Sway bars

[LA_phantom_240]

Doing a little reading about how upgrading/changing different suspension components affects the car's handling characteristics and ride quality (cause my s14 is my dd lol)... and read (in short) that upgrading the front bar and not the rear will increase understeer, while upgrading just the rear will increase oversteer. Now what about when you upgrade both bars (non adjustable, of course)? I'm guessing that if their increase in stiffness retains the factory proportions, then the car should be tighter without changing the more basic oversteer/understeer characteristics of the car through a corner. Would I be correct in assuming so?

[racepar1]

It depends on the sway bars. 240's like to have no rear sway or a stock rear sway combined with a beefy front sway for the track. This is due to the eccessive amounts of anti-squat in the rear suspension, especially on the s-13's. Running a soft rear sway or none at all helps transfer more weight to the rear of the car and keep the ass planted coming off the corners. It will give the car slightly more understeer off the throttle, but that can be tuned out of the car using other suspension adjustments. For a beginner it is better to have a car that has a small amount of understeer anyways as the car is more stable and consistent. For drift you want thicker front and rear bar as it will quicken the transition to on-throttle oversteer. Most 240's came with 24mm front and 15mm rear sway bars, I have also seen 25mm front bars and 17mm and 21mm hollow (hicas/jdm) rear sway bars that came from the factory too (those are for the s-13, IDK about the s-14's). That is a difference of 9mm between the front and rear bars. Making that difference smaller or larger is what will affect the balance of the car.

[MrChow]

Funny you ask now. I just finish resetting my coils to match my new front sway bars.

The feeling you will get when you put on a aftermarket sway bar is the cornering feels "flat" aka anti-roll bars.

Now I know I'm not expert but I'll give my opinions (<- check it people don't flame) about this. Also excuse my english if it isn't the best.

I also have S14 that i DD. My was a base model so no rear sway bar. When I put on my rear sway bar on it was just amazing. It felt like I cut over 50% of the roll. Also characteristics of the car changed. I didn't understeer as much and oversteer well oversteer was already crazy in the rear without it but now it smooth as it didn't just snap out.
Now with the front it was the same thing, then again I've only had it for a week now with no good front tires... But it did cut back more roll which I wanted cuz I was use the coils to do that but then I couldn't transfer the weight of my car like I wanted. But so far it I haven't gotten to do too much with it on.
Sway don't really increase under/oversteer IMO it more less it coming up so fast. I'm pretty sure some is going to post something better. I just wanted to give you my opinion.

[MrChow]

It depends on the sway bars. 240's like to have no rear sway or a stock rear sway combined with a beefy front sway for the track. This is due to the eccessive amounts of anti-squat in the rear suspension, especially on the s-13's. Running a soft rear sway or none at all helps transfer more weight to the rear of the car and keep the ass planted coming off the corners. It will give the car slightly more understeer off the throttle, but that can be tuned out of the car using other suspension adjustments. For a beginner it is better to have a car that has a small amount of understeer anyways as the car is more stable and consistent. For drift you want thicker front and rear bar as it will quicken the transition to on-throttle oversteer. Most 240's came with 24mm front and 15mm rear sway bars, I have also seen 25mm front bars and 17mm and 21mm hollow (hicas/jdm) rear sway bars that came from the factory too (those are for the s-13, IDK about the s-14's). That is a difference of 9mm between the front and rear bars. Making that difference smaller or larger is what will affect the balance of the car.
^^ that works. Interesting... I can't wait to get on the auto-x or the track with my friend and see what he say about it. Skip barter drivers are cool to have as friends. =P

[MikeisNissan]

So having just a front beefy sway bar is better than having both front and rear?

[racepar1]

I can confirm that a stiffer rear sway makes a large difference in the overall roll of the car. With my s-13 I had godspeed sway bars (30mm hollow front, 28mm hollow rear). I found myself chasing the tail all around the track at the streets of willow and a couple corners at big willow as well. I then changed the rear bar out for the 21mm hollow hicas bar and it hooked up much better. I was at an autocross event with that set-up and was basically drifting half the course, so I decided to remove one of the rear endlinks (basically dis-ables the sway bar). The car was 100% more planted and I didn't notice anymore understeer there. I then changed out my front bar for a cusco 28mm hollow bar and left the rear sway out for my last event at the streets. The car was 2 seconds faster on a track that was 1-2 seconds slower due to rain the night before and new pavement. I noticed more understeer off the throttle than I would like though, which I will adjust out in other ways. On an s-14 the rear grip problem is not as significant as on s-13's because they have less rear anti-squat. It is probably a good idea to upgrade both bars and try to keep the difference between the front and rear swaybar diameters as close to stock as possible to start with.

[racepar1]

So having just a front beefy sway bar is better than having both front and rear?

For grip on s-13's yes it is.

[OptionZero]

also note that sway bar bushings will affect some feel as well

part of the improvement of adding new swaybars is that our old ones (if u had 'em) might have worn bushings

Progress bars come with a spherical bushing, and SPL sells some as well (but they are baaank)

Some member here or on another forum pieced together his own

[MikeisNissan]

I have Godspeed front and rear waiting to be installed on my s14. Do you guys know where I can get better bushings than the one Godspeed includes? Like Racepar said it is 30mm up front and 28mm in the back.

[LA_phantom_240]

Well my s14 is an SE and so it has the sway bar from the factory. I hate how the car feels around longer corners around 60-80mph, like when I'm trying to get through New Orleans' elevated highways there are a couple of turns that scare the shit out of me... and in all my s13s that has never happened even when I was running Tein S-Tech springs on KYB GR-2's on my black s13. My s14 seems to want to understeer a LOT more than it should. I'm running 215/45/ZR17 BF-Goodrich G-Force KDW's up front on 5-Zigen FN01R-C's 17x8, and 225/45/ZR17 Falken Ziex tires stretched (cause I bought the rims like that LOL) on 17x9 FN's in the rear. I'm going to get coilovers soon cause my stock suspension is worn out, albeit better than it was when it was lowered.

[racepar1]

Dude your set-up is not consistent at all, that is most likely why the car feels weird. Your tires are staggered and different tires front and rear to begin with, that will definitely make the car feel strange. Before you spend money on sway bars you need to get a good set of tires on the car. The car will most likely feel pretty much the same with sways, just with less body roll.

[racepar1]

I have Godspeed front and rear waiting to be installed on my s14. Do you guys know where I can get better bushings than the one Godspeed includes? Like Racepar said it is 30mm up front and 28mm in the back.

I took a set of energy urethane bushings for my stock s-13 sways and machined them out to fit the godspeed bars. As far as I know there is no off the shelf solution.

[LA_phantom_240]

Dude your set-up is not consistent at all, that is most likely why the car feels weird. Your tires are staggered and different tires front and rear to begin with, that will definitely make the car feel strange. Before you spend money on sway bars you need to get a good set of tires on the car. The car will most likely feel pretty much the same with sways, just with less body roll.

Rears only have about 35% life left in them. Any suggestions? And the fronts have about 80% left on them. I like the front tires, honestly. They're a bit noisy, but I have yet to lock them up under, "Fuck fuck fuck fuck fuck fuck!" kinda braking, and they do well in the rain. When I replace them I'm going a little wider with a 225/40 and the rears will get 245/40's. I also have other underlying problems with the car such as bad motor mounts, bushings that need replacing, etc.

[4bangers]

racepar1 - so you'd recommend same tire brand for all corners and size? I'm asking b/c I saw many people on here got different tires for front and rear, also run stagger. Is that only good for drifting since they don't want grip anyways? but for track it's different? thanks for all of your informative comments.

[Forge_55b]

what i did when i used to autox (miata tho) is run the same tire and size all around on the same size wheels just cause it was consistent in regards to grip on every corner, a miata is close to 50/50 weight distribution tho so on a 240 i guess tire sizes may need to compensate for it

that said, don't expect suspension components to make up for non grippy tires. grippy tires on a stock suspension will usually be more predictable then crap tires on a non-stock suspension

[LA_phantom_240]

what i did when i used to autox (miata tho) is run the same tire and size all around on the same size wheels just cause it was consistent in regards to grip on every corner, a miata is close to 50/50 weight distribution tho so on a 240 i guess tire sizes may need to compensate for it

that said, don't expect suspension components to make up for non grippy tires. grippy tires on a stock suspension will usually be more predictable then crap tires on a non-stock suspension

I need to take a little air out of my fronts, cause I usually run them a little high. But they are supposedly some of the best street tires there are.

[ScarredOne]

Is this all for street driving, or a specific type of track use? If you haven't already, you can try getting an alignment--I'm curious as to what your current settings are. Wider front tires would be nice as well, I like the Federal SS595 for street tires. If you really don't care about looks and just want grip, you should be able to fit up to a 255 on your front 8" wheels. I typically like running as much rubber as possible on all corners of the car for grip driving (I don't care about tramlining); it's definitely not something to shy away from for the sake of the staggered look. You could go wider on your 9's though.

[racepar1]

racepar1 - so you'd recommend same tire brand for all corners and size? I'm asking b/c I saw many people on here got different tires for front and rear, also run stagger. Is that only good for drifting since they don't want grip anyways? but for track it's different? thanks for all of your informative comments.

Of course it is best to have the same brand and model tires on all 4 corners for grip driving! That's just common sense right there. Unless you have pretty high HP it is a good idea to run the same size tires on all 4 too. I have 255/40/17 azenis on all 4 corners of my car and my car is unquestionably stupid fast in the corners, the stock KADE is starting to hold me back now.

Is this all for street driving, or a specific type of track use? If you haven't already, you can try getting an alignment--I'm curious as to what your current settings are. Wider front tires would be nice as well, I like the Federal SS595 for street tires. If you really don't care about looks and just want grip, you should be able to fit up to a 255 on your front 8" wheels. I typically like running as much rubber as possible on all corners of the car for grip driving (I don't care about tramlining); it's definitely not something to shy away from for the sake of the staggered look. You could go wider on your 9's though.

The widest you can go with those wheels is 255 front, 275 rear. That will be a bit bulging though. I would personally reccomend 235's in the front and 255's in the back. That set-up will be pretty much square, actually just a BIT undersquare with the wheels

[LA_phantom_240]

Of course it is best to have the same brand and model tires on all 4 corners for grip driving! That's just common sense right there. Unless you have pretty high HP it is a good idea to run the same size tires on all 4 too. I have 255/40/17 azenis on all 4 corners of my car and my car is unquestionably stupid fast in the corners, the stock KADE is starting to hold me back now.



The widest you can go with those wheels is 255 front, 275 rear. That will be a bit bulging though. I would personally reccomend 235's in the front and 255's in the back. That set-up will be pretty much square, actually just a BIT undersquare with the wheels

Really? Well here's a pic of the car right now (back on stock suspension). Mind you I know the offset is ULTRA weak, cause they came off of an s13 so if you're gonna say anything about weak offset then fuck off. I know its weak. I needed newer rims that weren't bent and didn't have steel belts poking out. Yes all four stock rims were bent. I picked these up on the cheap, for less than the cost of the front tires. The fronts are pretty square. The rears are stretched to hell though lol.

http://i5.photobucket.com/albums/y152/phantom240/Headlight008.jpg
http://i5.photobucket.com/albums/y152/phantom240/Headlight002-1.jpg

I'm saving up to get some Work VS-XX wheels, so these will do for now.

Oh, and my car is a daily driver. Its my only car in fact. I drive it hard, and will eventually start attending local autocross events. At which point I'll get another set of wheels that will be more function over form. Right now I'm running a mix of form and function lol.

[4bangers]

my car is unquestionably stupid fast in the corners, the stock KADE is starting to hold me back now.


can you post your suspension set up please. I just want to have an idea of what part is needed and tune to make the car fast in a corner but still stable. I'm building my suspension right now and I want it to be as good as possible. Thanks

[slider2828]

I have ST Sways all around 22mm in the rear, and 27 or 29 in the front. Forgot what was ST's Specs, but its awesome... I run RT615s 225 in teh fronts and 245 SS595 in the rear.... Full megan track so 12/10 setup which I hate on street tires cause the front doesn't dip enough to put pressure on the tires to have good bite....

Thinking going 10kg/mm all around.

So far the car turns on a dime, but then it includes CS tension, Johnny Fraz Brace, New inner and outer tie rods, full SPL rear links, all around poly bushings, dun have fender braces, ... But everything ads up. Just doing small things like sway, tension arms bushings, and coilovers or good setup like GC Coils and Koni shocks.... Its a pretty good formula....

[racepar1]

can you post your suspension set up please. I just want to have an idea of what part is needed and tune to make the car fast in a corner but still stable. I'm building my suspension right now and I want it to be as good as possible. Thanks

Check out my vb pic gallery I have a full mod list and pics there.

[racepar1]

I have ST Sways all around 22mm in the rear, and 27 or 29 in the front. Forgot what was ST's Specs, but its awesome... I run RT615s 225 in teh fronts and 245 SS595 in the rear.... Full megan track so 12/10 setup which I hate on street tires cause the front doesn't dip enough to put pressure on the tires to have good bite....

Thinking going 10kg/mm all around.

So far the car turns on a dime, but then it includes CS tension, Johnny Fraz Brace, New inner and outer tie rods, full SPL rear links, all around poly bushings, dun have fender braces, ... But everything ads up. Just doing small things like sway, tension arms bushings, and coilovers or good setup like GC Coils and Koni shocks.... Its a pretty good formula....

The car doesn't "bite" because the suspension and wheel/tire packages are poorly chosen and set-up. The rear sway is too big for grip, the spring rates are too stiff for grip, the tires are different brands and totally different tires altogether. Don't get me wrong, I am not trying to put you down and talk shit to you. Your car is clearly set-up for drift and I am willing to bet that your set-up works for drift pretty well. As a grip set-up though that is pretty weak and I just want the OP to know that. As far as the OP's wheels go, it is not that bad of a set-up. Sure the offsets are pretty weak, but FN's are good, strong wheels. Rather than saving for another set of "baller" wheels right off the bat I think you should get some good tires for the ones you have and set-up the suspension. Baller wheels are pointless if your car is still sitting at stock ride heighth with cheap tires. Get spme tires and suspension and start enjoying the car man, fuck "baller".

[Rnz520]

I like this thread, very imformative.
Racepar1 are you saying you dont reccomend running an aftermarket rear sway bar or a sway bar at all for grip?, because from doing research I have heard of a lot of people saying the same thing.
Also what spring rates do you reccomend for grip, not drift?

[spool_sample]

Some member here or on another forum pieced together his own

Spherical endlinks are very easy to make. It's $30-$40 bucks in McMaster parts... a male/female set of 3/8" rod ends, jam nuts, bolts, and spacers. They're easy to mount, too, if you have Whiteline bars, since they directly replace the stupid S bushing clusterfuck thing. If you wanted to use them with other bars that use stock endlinks, you would have to have a bracket made to be able to mount them to the control arm correctly.

The ones that come with the Progress bar are made from Aurora rod ends, which is pretty nice, considering that you can get the whole sway bar package for under $200.

[Jza]

Wow,... very good info. Since everyone is asking questions. Here is mine. :)

I ahve a 91' SE hatchback with HICAS.
-Whiteline front and rear tower bars.
-Whiteline front (measured ~25.5mm)and rear (measured 22mm) sway bars.
-AGX adjustable shocks with Whiteline springs.
-Rota Grid Off-Road wheels 16x8+10 with 225/50R16 Sumitomo HTR Z tires all around.

I cannot tell if I like the balance for under/over steering yet. BUT, I have alot of body roll when I make tight turns. I was told that the suspension setup is very good for most 240sx. However, I don't feel that way because of the body roll. What can I do to eliminate the body roll? I am not sure if the body roll was caused by the HICAS. I didn't disable it because I have not decided if I will my 240sx for grip. Well, I bought the 240sx for grip driving initially.

I was thinking to get the Godspeed sway bar set because they are much thicker. But, after I read this thread. I don't know what I should do next. Please help!

[91SuperS13]

Man I wish this thread was here like 5 months ago. I just bought some adjustable whiteline sways for front and rear. I think what I've read so far though is I'm going to set the rears for the lowest stiffness setting. I still want to eliminate the roll.

good moves I've made, according to this thread, is energy master bushing kit, inner and outer tie-rods, tension rods, and Koni yellows. For the most part, the only part that I really bought with performance in mind were the sways. The rest of the stuff I bought was just to replace worn out OEM equipment.

ironically my car is in the shop right now. I get it back early this week and can't wait to dial it in...

[S14SwimShark105]

I think it's stupid to run without a rear sway bar. Just set it to the softest setting if you have to. I have whiteline sway bars front and back in my S14 with stock endlinks with polyurethane bushings and it handles great.

I don't know why some people run without a rear sway bar, maybe they are just adding gas too early coming out of a turn and end up getting a little loose and think the sway bar is too stiff. Find some other way to get the car to put down power but don't entirely remove the rear sway bar.

[slider2828]

Like I said, this is what I said lack of bite for street use. As per track use, I don't have a problem as I run 225 slicks in the front and 245 slicks in the rear. I run Goodrich R1's all around. Hence, like I said spring rates are not good for the street hence I rather run 10/10's all around for the street. Aragosta/AST Run 9.7 and 7.3 I believe which is good for the track or street because of their superior dampening.

I don't have money for a second set of coilovers and so I will see if I can reduce the spring rate with some future swift springs, but those run 300+ for 4 springs and I doubt the valving would match the springs..... So oh wellz what can I do.... Run it and try it....

Without knowing other suspension settings and what I use the settings for it might be difference. I run autox in this setup and actually run quick well. I also have 300zx fronts on hence the bias between the large fronts and the stock rears don't help as well, but that is partly rectified through balancing the rear with more aggressive pads. With proper preload and dampening adjustments, I don't have a problem running track as well. I have also raced bikes for 3 years in different series as well and do my own setup and tuning. I prefer to have more oversteer as I run less camber than most people allowing me to modulate better which makes my car transition a lot better as well and corner entry.

But like I said, I wouldn't suggest my setup for the street use, but with corect tire choices on teh track and pending on surface with autox, I don't have that problem. I make pretty good HP on my SR, but I don't get spin because of controllable boost curve at speed. Sort of my own tranction control through updated Greddy Profecs and more "response" oriented cam setup.

Eh... but whatever to each their own... But some people don't run rear sways and some people do... it all depends on the driving feel and I prefer more oversteer, some maybe less, it all depends....

[Forge_55b]

Yeh, slider you made the most important point, that it really comes down to personal preference and experience.

i think a lot of the problems that people have is that they do all these mods to their car without the knowledge of why you should do it in the first place or how to even tune it correctly, etc etc.

so instead of getting "upgrades" get a set of good tires and lightweight wheels (VS-XX are tanks and FN01's are actually decent) and seat time for the track or autox

also having non-flush offsets is actually good in regards to suspension geometry fwiw

[Wiisass]

For the original question, aftermarket sway bars do not maintain the same front to rear balance as the stock sway bars. Most of them will stiffen the rear bar a much greater percentage than the front, this may not be a bad thing depending on how much it is actually stiffened.

Another thing to understand is that sway bars are just springs and they are meant to work with the other springs on the car which are the suspension springs and the tires. The sway bars need to be matched with the suspension springs and the rest of the car to get the best balance. This is hard for most people because they don't have all those numbers and many people don't really understand how everything works together.

For a street car, stiffer sway bars at both ends will usually be fine depending on suspension spring rates. With coilovers on a street car, I would recommend just sticking with stock sway bars. For a track car, I would recommend softer than stock sway bars in the front and stock or slightly stiffer in the back. I know a lot of people run successful autox cars with a stiff front bar and no rear bar, but it's an autox setup and by definition they make no sense at all.

I am not a fan of stiff sway bars, they are not needed when you're running stiffer springs. Even the stock front bars on every car that I've measured have been much stiffer than I would like. But people don't realize that and I guess people can really feel the difference between 0.2 degrees of roll at 1g after upgrading their stock sway bars to some aftermarket ones when they already have coilovers on the car. But I don't get how people can feel that 0.2 degree change in roll at 1g and they don't realize that the dampers they're running on are crap.

Oh, and anti-squat has nothing to do with total weight transfer. It has to do with the distribution of weight transfer under acceleration. But it's the same thing as roll center, just in the side view. People don't understand it and think its a bad thing and then try and figure out ways around it because they don't know how to make it work for them. Essentially, it just means that more of the load is transferred directly through the suspension arms instead of through the springs. But no one knows what percentage of anti-squat these cars have or what the side view instant center height is.

But anyway, sway bars. In my opinion, if it's a street car and you have coilovers, don't even waste the money, get better bushings for the stock ones and make solid endlinks and you will be more than fine. For a track car, do the same and if you have to get sway bars get something you can adjust. At least put some thought into your setup.

I just get worried that there are too many answers but not enough reasons. Too many people think they know what they're doing or think that because some band-aid worked for them, that's the way you fix things. People are just adjusting what they can and whatever they don't understand is bad or causing problems for the car. But whatever.

[racepar1]

All I know is this, when I removed the rear sway bar the car picked up at least 1.5 seconds on the track and was much more controllable and balanced on the throttle. I understand that this set-up will not be everyone's cup of tea, but it is perfect for me. With a rear sway in the car the car was very prone to on-throttle oversteer, even with toe in in the rear. Without a rear sway the car was perfectly neutral on the throttle and was actually lifting the inside front tire coming off the slow corners. Wisass you say that anti-squat has nothing to do with weight transfer, but I beg to differ. Anti squat prevents the rear suspension from compressing under load. If the suspension can't compress as much then less weight is being transfered there. If you set your car on a level surface, let's say the weight distribution is 50-50. Now if you have that same car sitting on a mildly sloped driveway I will guarantee you that the weight distribution is no longer 50-50. Whichever side is lower will pick up more weight. That's very simple logic right there. Are there other ways to adjust out some of the on-throttle oversteer problems that i was having, of course there are, but removing the rear sway worked extremely effectively.

[LA_phantom_240]

Hmm... maybe the crappy spring/strut combo I had was also contributing to understeer. The front struts I can barely compress with my weight, and I weigh like 280lbs lol. The rears however I could compress a good bit. Maybe too much weight was being transferred back there and not enough weight being on the front not making the tires bite like they should.

[Wiisass]

I'm not saying less rear roll stiffness is not the answer. But there is more to it than blankly saying that no rear sway bar is the best setup. It's not as simple as that. And just because it works for people does not mean that there is a better place that they could optimize their setup. Removing the rear sway is the quick fix, but probably not the best.

And you're going to try and argue about anti-squat with me? Really?

You don't understand how anti-squat works. Go look it up and read about it and understand it. It's the same principle as roll center. It's just in the side view.

Anyway, just to quickly prove you wrong. Weight transfer under acceleration is a function of acceleration, mass, wheelbase and CG height. It is governed by the laws of physics. The weight transfer still happens no matter what the suspension geometry is. So when you accelerate, weight is tranferred from the front to the back. The acceleration times the mass of the vehicle creates a force that is acting at the CG. This force is the distributed based on the suspension geometry into elastic load transfer and geometric load transfer. Geometric load transfer goes through the rigid suspension links and elastic load transfer is what compresses the suspension.

If you have a side view instant center at the same height as the CG, you can have no elastic load transfer and the suspension will not move at all, but load will still be transferred. The only time load will not be transferred is if the CG height is at ground level. Which will never happen.

So now hopefully you understand it a little better. There are more detailed explanations out there. But that's the basic idea. So load transfer still happens, it just is distributed through the suspension and through the springs.

[Wiisass]

Hmm... maybe the crappy spring/strut combo I had was also contributing to understeer. The front struts I can barely compress with my weight, and I weigh like 280lbs lol. The rears however I could compress a good bit. Maybe too much weight was being transferred back there and not enough weight being on the front not making the tires bite like they should.

What struts/shocks and springs are you running? The you should always be able to compress shocks a little by just putting your weight on them. It sounds like either there's something wrong with the fronts or the rears are blown.

But a shock bases the amount of force is puts out on the speed at which the shaft is traveling. So by loading it like that, after you overcome and stiction, as long as you're putting enough force to compress the gas in the damper and the spring, it should move. So if you have lowering springs on the front and it's not moving much, then something is definitely wrong.

I would get that figured out before you even think about sway bars.

[S14SwimShark105]

There are too many ways to tune how the car handles, and sway bars are just one of them. I'm sure some of you guys have heard of the small bar stiff springs or big bar soft springs theory. You can try to mess around with the size of the sway bars and the stiffness of the springs as well as the dampeners.

Racepar1 I think I remember you mentioning somewhere that you have a stock ka24de. I don't understand how you can get throttle-on oversteer with the stock bar. You shouldn't even be accelerating the car through a corner. If you are doing anything else but unwinding the steering wheel or smoothly letting off the brakes, you might be doing something wrong. Instead of trying to adjust the car, try to adjust your driving style first.

And you said you are lifting the inside front tires coming off of slow corners? Something is wrong with your set-up or your driving style. You don't want to be lifting ANY tires off the ground at any time.

I also have a somewhat stock ka24de, intake headers and exhaust. Sure I can get it to throttle-on oversteer if I wanted to, but thats not what I want, so I don't.

[racepar1]

Wow,... very good info. Since everyone is asking questions. Here is mine. :)

I ahve a 91' SE hatchback with HICAS.
-Whiteline front and rear tower bars.
-Whiteline front (measured ~25.5mm)and rear (measured 22mm) sway bars.
-AGX adjustable shocks with Whiteline springs.
-Rota Grid Off-Road wheels 16x8+10 with 225/50R16 Sumitomo HTR Z tires all around.

I cannot tell if I like the balance for under/over steering yet. BUT, I have alot of body roll when I make tight turns. I was told that the suspension setup is very good for most 240sx. However, I don't feel that way because of the body roll. What can I do to eliminate the body roll? I am not sure if the body roll was caused by the HICAS. I didn't disable it because I have not decided if I will my 240sx for grip. Well, I bought the 240sx for grip driving initially.

I was thinking to get the Godspeed sway bar set because they are much thicker. But, after I read this thread. I don't know what I should do next. Please help!

After setting the godspeed front bar next to a cusco one I would not reccomend the godspeed bars. The distance between where the bar goes through the sway bar to frame bushing to where the endlink bolts on is somewnere around 3/4" longer on the godspeed bar than it is on the cusco bar. That means the suspension has more leverage on the sway bar making a lot of that extra bar thickness useless. The sway bar that I like the best is the progress sways. They come with spherical endlinks on the front bar and from what I have heard from other owners the range of adjustment is pretty wide in comparison to other adjustable sways. For about $200 for the front bar it is a pretty damn good buy. For the money the godspeed front bar is ok, the rear is waaaayyyyyyyy too thick though.

I think it's stupid to run without a rear sway bar. Just set it to the softest setting if you have to. I have whiteline sway bars front and back in my S14 with stock endlinks with polyurethane bushings and it handles great.

I don't know why some people run without a rear sway bar, maybe they are just adding gas too early coming out of a turn and end up getting a little loose and think the sway bar is too stiff. Find some other way to get the car to put down power but don't entirely remove the rear sway bar.

"Handles great" is a relative term. I would most likely not bew happy with your car and you would most likely not be happy with mine, different drivers like different set-ups. There is no such thing as "adding gas too early" the earlier you can pick up the throttle, the better 100% of the time. I think that it is generally better to run a rear sway of some sort if you can get away with it, but if the car feels better without one, why not run it like that. I did not come to my opinions on rear sways by blindly following what other people told me on the forums. I went out and tried several different rear sway set-ups and ended up liking no rear sway the best so far. I think for the next event I will try it with thw stock (15mm)rear sway and see how I like that.

Yeh, slider you made the most important point, that it really comes down to personal preference and experience.

i think a lot of the problems that people have is that they do all these mods to their car without the knowledge of why you should do it in the first place or how to even tune it correctly, etc etc.

so instead of getting "upgrades" get a set of good tires and lightweight wheels (VS-XX are tanks and FN01's are actually decent) and seat time for the track or autox

also having non-flush offsets is actually good in regards to suspension geometry fwiw

Most people don't understand that drastically changing wheel offsets changes the steering geometry. The scrub radius designed into the steering was designed with the stock wheel offset, drastically changing the offset can negatively affect that. As I understand it the scrub radius is pretty much non-adjustable, but maybe wisass could shine a bit of light on that as he is better with geometry than me. +1 for you my friend!

Hmm... maybe the crappy spring/strut combo I had was also contributing to understeer. The front struts I can barely compress with my weight, and I weigh like 280lbs lol. The rears however I could compress a good bit. Maybe too much weight was being transferred back there and not enough weight being on the front not making the tires bite like they should.

The first thing you need to get sorted if you want your car to handle well is the spring/shock combo. Sway bars will be a waste of money with shitty suspension and tires.

[racepar1]

I'm not saying less rear roll stiffness is not the answer. But there is more to it than blankly saying that no rear sway bar is the best setup. It's not as simple as that. And just because it works for people does not mean that there is a better place that they could optimize their setup. Removing the rear sway is the quick fix, but probably not the best.

I tend to agree with you here. It is definitely not the best answer, but it works well and requires no money and very little time. Most of us don't have the money and time to change springs and alignment settings for every event untill we find what works. Much less the knowledge (and time) to find and calculate what would be the best CG, roll centers, roll axis, anti-squat angle, camber and toe curves, steering geometry, etc........ (the list goes on and on) so we have to make the simple adjustments to get the car to work.

And you're going to try and argue about anti-squat with me? Really?

You don't understand how anti-squat works. Go look it up and read about it and understand it. It's the same principle as roll center. It's just in the side view.

Anyway, just to quickly prove you wrong. Weight transfer under acceleration is a function of acceleration, mass, wheelbase and CG height. It is governed by the laws of physics. The weight transfer still happens no matter what the suspension geometry is. So when you accelerate, weight is tranferred from the front to the back. The acceleration times the mass of the vehicle creates a force that is acting at the CG. This force is the distributed based on the suspension geometry into elastic load transfer and geometric load transfer. Geometric load transfer goes through the rigid suspension links and elastic load transfer is what compresses the suspension.

If you have a side view instant center at the same height as the CG, you can have no elastic load transfer and the suspension will not move at all, but load will still be transferred. The only time load will not be transferred is if the CG height is at ground level. Which will never happen.

So now hopefully you understand it a little better. There are more detailed explanations out there. But that's the basic idea. So load transfer still happens, it just is distributed through the suspension and through the springs.

Of course load is transfered, that is simple logic, fuck physics. Anti-squat re-directs the force trying to compress the suspension to effectively bind the suspension and prevent compression. I don't think that significantly binding the suspension is the right way to control suspension movement and in the end diminishes our ability to adjust the car to suit or preferences. If removing the rear sway has no effect on load transfer than why does it change the balance of the car so significantly? It obviously DOES effect load transfer as if there were no more load on the rear tires the car would feel pretty juch exactly the same only with more body roll. And who is arguing, this is a discussion. Arguing involves feelings, specifically anger, I am not getting upset, only interested. I take up every single opportunity that presents itself to learn something from you and a select few other zilvia members that really know what's up.

[Forge_55b]

ok i just checked something and there was no explanation on what sway bars or anti roll bars actually do mechanically so i think this link should give more incite on sway bars

http://auto.howstuffworks.com/question432.htm

[wangan_cruiser]

i have a largus sway bar front and back with tokico blues and eibach springs. it feels solid no roll or anything compare to stock. i only set it to the softest (3 holes each side L and R stiffness adjustment from inside hole to outside. mine is on the last hole from outside) i like these sway bars. but they are bank haha. i need better links anyone know where i can get stock type links?

[racepar1]

Racepar1 I think I remember you mentioning somewhere that you have a stock ka24de. I don't understand how you can get throttle-on oversteer with the stock bar. You shouldn't even be accelerating the car through a corner. If you are doing anything else but unwinding the steering wheel or smoothly letting off the brakes, you might be doing something wrong. Instead of trying to adjust the car, try to adjust your driving style first.

What are you talking about? Ideally you want to be full throttle from the apex of the corner on. The on throttle oversteer came on as I picked up the throttle at or just after the apex.

And you said you are lifting the inside front tires coming off of slow corners? Something is wrong with your set-up or your driving style. You don't want to be lifting ANY tires off the ground at any time.

Ideally you are right it is always better to have all 4 tires down, but with the inside front is the air I can feel no loss of directional control of the car. The one time that the car started to understeer there I just blipped the throttle a bit and it began rotating as it should. It is quite common for fast RWD cars to pick up the inside front on tight corners. My set-up is absolutely not perfect by any means, but trust me it works very well for what I have.

I also have a somewhat stock ka24de, intake headers and exhaust. Sure I can get it to throttle-on oversteer if I wanted to, but thats not what I want, so I don't.

Wouldn't it be better if the car was sooo planted in the rear that you couldn't really get on-throttle oversteer if you tried, just nice smooth rotation? That is the point that my set-up is at right now, it is quite difficult to really get to the point of describing it as "oversteer" but it ROTATES on the throttle quite nicely. As far as my driving style goes, I'm sure we'll see eachother at the track one of these days and we can have our little pissing match about whose driving style needs work there, on the track where it really matters.

[S14SwimShark105]

haha I wouldn't mind running with you at the track racepar1 any day man. No need for any pissing matches here, I'm always down to learning new things, espcecially driving styles. I wasn't saying your driving style sucked, but if you were continueing to get power-on oversteer then obviously you were pushing the car beyong what it can handle and that will only result in slower times. I'll be out with NASA on the 21st and the 22nd at ButtonWillow if you want to join.

Randall

[Jza]

After setting the godspeed front bar next to a cusco one I would not reccomend the godspeed bars. The distance between where the bar goes through the sway bar to frame bushing to where the endlink bolts on is somewnere around 3/4" longer on the godspeed bar than it is on the cusco bar. That means the suspension has more leverage on the sway bar making a lot of that extra bar thickness useless. The sway bar that I like the best is the progress sways. They come with spherical endlinks on the front bar and from what I have heard from other owners the range of adjustment is pretty wide in comparison to other adjustable sways. For about $200 for the front bar it is a pretty damn good buy. For the money the godspeed front bar is ok, the rear is waaaayyyyyyyy too thick though.


Just wonder if the HICAS play a role in body roll?

[a_ahmed]

get rid of hicas urgh, worst shit nissan could put on a car :(

[Jza]

get rid of hicas urgh, worst shit nissan could put on a car :(


But, HICAS could do some good on grip driving.

[luftrofl]

[quote=racepar1;2080900]
Of course load is transfered, that is simple logic, fuck physics. Anti-squat re-directs the force trying to compress the suspension to effectively bind the suspension and prevent compression. I don't think that significantly binding the suspension is the right way to control suspension movement and in the end diminishes our ability to adjust the car to suit or preferences. quote]

From what I can tell, anti-squat allows weight to go to the rear without compressing the springs. I think that the advantage of this would be to allow for softer rear springs, softer rear shocks, and less rear suspension travel to be used without worring about bottoming out on bumps under acceleration.

I'm hardly an expert, but this quote from whiteline stuck with me: "[anti-squat] has the effect of increasing the spring rate, as the rear end does not compress as much during acceleration."
-from www.whiteline.com.au/articles/WL_Solid_Axle_Antisquat.pdf

I reserve the right to be completely wrong :sadwavey:

[LA_phantom_240]

What struts/shocks and springs are you running? The you should always be able to compress shocks a little by just putting your weight on them. It sounds like either there's something wrong with the fronts or the rears are blown.

But a shock bases the amount of force is puts out on the speed at which the shaft is traveling. So by loading it like that, after you overcome and stiction, as long as you're putting enough force to compress the gas in the damper and the spring, it should move. So if you have lowering springs on the front and it's not moving much, then something is definitely wrong.

I would get that figured out before you even think about sway bars.

Well I traded a guy locally some of my spare parts for a set of Tokico blues with dropzone springs (shut up, I don't want to hear it. I'm back on stock now lol). Those springs were SO shitty.... Mind you, visually the car was amazingly low, but I dunno if it was the springs or the struts, but the car was REALLY unstable on bumps and the highway, and the fronts had a nasty habit of smashing the top of the strut way too easily... And the springs on the rear were so short that they didn't sit snug against the perches and with them off the car... so I'm thinking maybe they were s13 springs and the fronts were sweating?

[racepar1]

But, HICAS could do some good on grip driving.

Hicas is not what you want. It makes the rear of the car somewhat un-predictable and very vague feeling. It almost feels as if the rear suspension is connected to the rest of the car with a rubber band. Driving feel is everything when you are really pushing a car hard and hicas diminishes your connection (as a driver) to the car.

[Wiisass]

Well I traded a guy locally some of my spare parts for a set of Tokico blues with dropzone springs (shut up, I don't want to hear it. I'm back on stock now lol). Those springs were SO shitty.... Mind you, visually the car was amazingly low, but I dunno if it was the springs or the struts, but the car was REALLY unstable on bumps and the highway, and the fronts had a nasty habit of smashing the top of the strut way too easily... And the springs on the rear were so short that they didn't sit snug against the perches and with them off the car... so I'm thinking maybe they were s13 springs and the fronts were sweating?

So is it the stock ones that won't compress or the old ones? If it was with the dropzone setup, it sounds like you were just on the bumpstops the whole time. Which will make it feel very stiff because nothing is able to compress.

I would really do shocks/struts and springs before doing anything else.

I tend to agree with you here. It is definitely not the best answer, but it works well and requires no money and very little time. Most of us don't have the money and time to change springs and alignment settings for every event untill we find what works. Much less the knowledge (and time) to find and calculate what would be the best CG, roll centers, roll axis, anti-squat angle, camber and toe curves, steering geometry, etc........ (the list goes on and on) so we have to make the simple adjustments to get the car to work.



Of course load is transfered, that is simple logic, fuck physics. Anti-squat re-directs the force trying to compress the suspension to effectively bind the suspension and prevent compression. I don't think that significantly binding the suspension is the right way to control suspension movement and in the end diminishes our ability to adjust the car to suit or preferences. If removing the rear sway has no effect on load transfer than why does it change the balance of the car so significantly? It obviously DOES effect load transfer as if there were no more load on the rear tires the car would feel pretty juch exactly the same only with more body roll. And who is arguing, this is a discussion. Arguing involves feelings, specifically anger, I am not getting upset, only interested. I take up every single opportunity that presents itself to learn something from you and a select few other zilvia members that really know what's up.

It's not just the adjustments, it's the people chasing their tails because they're trying to account for their new sweet ebay parts that they paid less than the materials would be worth if they were actually decent materials. It's stupid purchases with no thought. It's trying to pair things together that shouldn't work together. And it's the fact that there are only a couple people on here that really understand suspensions.

Physics is awesome, deal with it. Anti-squat does not bind the suspension, it just forces the car to react the loads differently. Look up jacking and roll center heights and then apply it to the side view.

When did I say that anti-roll bars do not affect load transfer? The anti-squat discussion is only in reference to longitudinal accelerations. ARB's do affect load transfer, but again, not the amount, but the distribution, but in the lateral direction. Roll rate distribution and suspension geometry determine how the lateral force is distributed.

After setting the godspeed front bar next to a cusco one I would not reccomend the godspeed bars. The distance between where the bar goes through the sway bar to frame bushing to where the endlink bolts on is somewnere around 3/4" longer on the godspeed bar than it is on the cusco bar. That means the suspension has more leverage on the sway bar making a lot of that extra bar thickness useless. The sway bar that I like the best is the progress sways. They come with spherical endlinks on the front bar and from what I have heard from other owners the range of adjustment is pretty wide in comparison to other adjustable sways. For about $200 for the front bar it is a pretty damn good buy. For the money the godspeed front bar is ok, the rear is waaaayyyyyyyy too thick though.



"Handles great" is a relative term. I would most likely not bew happy with your car and you would most likely not be happy with mine, different drivers like different set-ups. There is no such thing as "adding gas too early" the earlier you can pick up the throttle, the better 100% of the time. I think that it is generally better to run a rear sway of some sort if you can get away with it, but if the car feels better without one, why not run it like that. I did not come to my opinions on rear sways by blindly following what other people told me on the forums. I went out and tried several different rear sway set-ups and ended up liking no rear sway the best so far. I think for the next event I will try it with thw stock (15mm)rear sway and see how I like that.



Most people don't understand that drastically changing wheel offsets changes the steering geometry. The scrub radius designed into the steering was designed with the stock wheel offset, drastically changing the offset can negatively affect that. As I understand it the scrub radius is pretty much non-adjustable, but maybe wisass could shine a bit of light on that as he is better with geometry than me. +1 for you my friend!



The first thing you need to get sorted if you want your car to handle well is the spring/shock combo. Sway bars will be a waste of money with shitty suspension and tires.

Your whole first paragraph is just poor observations. What are the rates of the two different bars? What additional roll rate do they provide? Do you realize that even with the longer moment arm, the Godspeed bar could be stiffer than the Cusco bar? And why do you think a super stiff bar is really necessary? So you know what percentage of the roll rate the bars are providing versus the spring?

The progress bar is a good choice. I still wish that it would go softer in the front than it does, but it is at least stock stiffness.

And I'm so sick of the driver preference argument. It's like saying that you like your car to handle like crap because you can drive it faster. The driver is the most important part and sometimes it's a remove and replace part.

Driver preference will play a little into it, but it should be in the fine details and not the course adjustments, especially on comparable cars. I just think people use it as an excuse to either justify their poor setup or use it as excuses for something else.

And there is a point where you can get on the gas too early, it sounds like that's the situation you are in. If you're getting on the gas super early and you're not putting down anything then it's too early. Do you think you were faster on the slower course becasue you weren't trying to overdrive the car, you weren't letting the inner drifter in you out and you were taking better lines and your timing was better? Could that be possible? It kind of sounds like it?

I'm not trying to criticize your driving because I've never seen you drive, but just from what you've been using as your examples in this thread. But I will say that I think something is wrong with your setup. If you're having power on oversteer problems with a stock KA, then something is wrong. You're either getting into it way too early, or your balance/alignment/tires/dampers are just not set correctly at all and you're losing rear grip for another reason. I don't know, something doesn't sound right.

Steering geometry is another thread. There's already enough crap in this one, so if you want to talk about it, start another thread. But I will say that scrub radius doesn't matter as much as people think.


ok i just checked something and there was no explanation on what sway bars or anti roll bars actually do mechanically so i think this link should give more incite on sway bars

http://auto.howstuffworks.com/question432.htm

Do not read that, it's horrible. It's not very good information. Just search on here for stuff that I've written about sway bars. They all have my views on the best way to use them, but the information with both sides is there as well. It will be a better read and much more informative.

What are you talking about? Ideally you want to be full throttle from the apex of the corner on. The on throttle oversteer came on as I picked up the throttle at or just after the apex.



Ideally you are right it is always better to have all 4 tires down, but with the inside front is the air I can feel no loss of directional control of the car. The one time that the car started to understeer there I just blipped the throttle a bit and it began rotating as it should. It is quite common for fast RWD cars to pick up the inside front on tight corners. My set-up is absolutely not perfect by any means, but trust me it works very well for what I have.



Wouldn't it be better if the car was sooo planted in the rear that you couldn't really get on-throttle oversteer if you tried, just nice smooth rotation? That is the point that my set-up is at right now, it is quite difficult to really get to the point of describing it as "oversteer" but it ROTATES on the throttle quite nicely. As far as my driving style goes, I'm sure we'll see eachother at the track one of these days and we can have our little pissing match about whose driving style needs work there, on the track where it really matters.

I already covered the always being on the gas thing. You do want to get on the gas as early as possible when you can use that power to move the car. If you're just getting into the gas to spin the tires, then you might as well just be drifting.

4 wheels will produce more lateral force when evenly loaded than 2 wheels carrying the same load. Again, something is wrong with your setup. I would really look into that. It just sounds like you're trying to make your car feel faster than actually be faster.

[racepar1]

It's not just the adjustments, it's the people chasing their tails because they're trying to account for their new sweet ebay parts that they paid less than the materials would be worth if they were actually decent materials. It's stupid purchases with no thought. It's trying to pair things together that shouldn't work together. And it's the fact that there are only a couple people on here that really understand suspensions.

I totally agree with you here. The propensity of 240 enthusiasts to buy cheap crap because it supposedly "does the same job" as other higher quality parts is staggeringly stupid. And then when they finally concede that the parts they are buying are crap they use the "I'm not a pro driver so who cares" excuse. Suspension geometry and design is so incredibly complicated that it takes years to really absorb, I'm working on it but not there yet.

Physics is awesome, deal with it. Anti-squat does not bind the suspension, it just forces the car to react the loads differently. Look up jacking and roll center heights and then apply it to the side view.

When did I say that anti-roll bars do not affect load transfer? The anti-squat discussion is only in reference to longitudinal accelerations. ARB's do affect load transfer, but again, not the amount, but the distribution, but in the lateral direction. Roll rate distribution and suspension geometry determine how the lateral force is distributed.

A soft rear sway will still have a marginal effect on the longitudinal load transfer because the rear of the car (specifically the outside rear) will be lower with a softer bar. This will marginally at best increase the total amount of weight transfered to the rear of the car. Taking out anti-squat will have a much more pronounced effect most definitely and probably without some of the negative side effects of running without a rear bar.

Your whole first paragraph is just poor observations. What are the rates of the two different bars? What additional roll rate do they provide? Do you realize that even with the longer moment arm, the Godspeed bar could be stiffer than the Cusco bar? And why do you think a super stiff bar is really necessary? So you know what percentage of the roll rate the bars are providing versus the spring?

The progress bar is a good choice. I still wish that it would go softer in the front than it does, but it is at least stock stiffness.

I think a stiffer front bar is better because a good amount of successful autocross cars run a stiff front bar with no (or a stock) rear bar. It works and there is no denying that. What makes you think that a softer front sway is any better? You have yet to explain that. I am operating on one major, but most likely correct, assumption when I state that the cusco bar is stiffer. The cusco bar is almost certainly made of higher quality steel than the godspeed one. Also the godspeed bar is only 2mm thicker than the cusco bar and with that much longer of a moment arm I don't see how it could possibly be stiffer.

And I'm so sick of the driver preference argument. It's like saying that you like your car to handle like crap because you can drive it faster. The driver is the most important part and sometimes it's a remove and replace part.

Driver preference will play a little into it, but it should be in the fine details and not the course adjustments, especially on comparable cars. I just think people use it as an excuse to either justify their poor setup or use it as excuses for something else.

Of course the set-up differences are in the details, but driver preference does make a difference.

And there is a point where you can get on the gas too early, it sounds like that's the situation you are in. If you're getting on the gas super early and you're not putting down anything then it's too early. Do you think you were faster on the slower course becasue you weren't trying to overdrive the car, you weren't letting the inner drifter in you out and you were taking better lines and your timing was better? Could that be possible? It kind of sounds like it?

I was driving the car harder this last event than the previous one at that track. I was picking up the throttle earlier and going full throttle instead of partial. The lines were exactly the same except in the re-paved section as I no longer had to straddle the split in the pavement. I have no inner drifter my friend, I am a driver to the death. You say that you are not trying to criticize my driving in the paragraph below, but it sure sounds like you are. I have been driving since I was a little kid, starting with a go-kart, and have always been one of the fast guys. That is not to say that my driving is perfect and I have nothing else to learn, just to say that the driving is not the main issue. Maybe I'm conceded, but the driving has never been hard for me.

I'm not trying to criticize your driving because I've never seen you drive, but just from what you've been using as your examples in this thread. But I will say that I think something is wrong with your setup. If you're having power on oversteer problems with a stock KA, then something is wrong. You're either getting into it way too early, or your balance/alignment/tires/dampers are just not set correctly at all and you're losing rear grip for another reason. I don't know, something doesn't sound right.

Of course there is something wrong with my set-up! It starts with the tein flex coilovers. If I had 8611's and could actually make a difference in how the car handles with my shock adjustments, rather than just how it rides, I'm sure I could do a lot more fine-tuning. I really haven't played with the knobe very much on my flexes because I am pretty convinced that it is futile. Shock tuning is the final step in tuning the suspension as well as it will make the smallest difference in the car. Now don't get me wrong, I am not saying that shock tuning does nothing. I'm pretty sure "getting into it way to early" isn't the problem, figuring out how to make all the various parts and pieces work together is. It takes a lot of tinkering to get it right and I know that. The initial lack of rear grip problem was the stupid stiff godspeed rear bar, since I have removed that I have not noticed any significant rear grip problems at an actual racetrack.

[Forge_55b]

tein flex....NO!!!! get a good inverted monotube setup with external reservoirs and 3 way adjustments, or just make things easy with konis and GC springs, then get it corner weighted assuming you have someone able to tune your suspension if you want to make things simpler but then......errr there are SOOO many more things that can be considered when it comes to suspension setup but things can be way too complicated so ill just make it simple

sway bars are great if you don't want to roll as much, they can make you faster or slower all depending on what your level of driving is and how your car is setup

[LA_phantom_240]

tein flex....NO!!!! get a good inverted monotube setup with external reservoirs and 3 way adjustments, or just make things easy with konis and GC springs, then get it corner weighted assuming you have someone able to tune your suspension if you want to make things simpler but then......errr there are SOOO many more things that can be considered when it comes to suspension setup but things can be way too complicated so ill just make it simple

sway bars are great if you don't want to roll as much, they can make you faster or slower all depending on what your level of driving is and how your car is setup

Corner weighted? Who the fuck corner weights their daily driver?

[Neejay]

Omg Cliff Notes Plz?!?

[Wiisass]

I totally agree with you here. The propensity of 240 enthusiasts to buy cheap crap because it supposedly "does the same job" as other higher quality parts is staggeringly stupid. And then when they finally concede that the parts they are buying are crap they use the "I'm not a pro driver so who cares" excuse. Suspension geometry and design is so incredibly complicated that it takes years to really absorb, I'm working on it but not there yet.

It's not even just cheap parts, it's poorly thought out parts. And everyone does not need to understand everything about suspension geometry and design, there's just too many myths and false information floating around that it hurts more than it helps.


A soft rear sway will still have a marginal effect on the longitudinal load transfer because the rear of the car (specifically the outside rear) will be lower with a softer bar. This will marginally at best increase the total amount of weight transfered to the rear of the car. Taking out anti-squat will have a much more pronounced effect most definitely and probably without some of the negative side effects of running without a rear bar.

Sway bars by definition only affect roll. The only effects you would see in pure longitudinal acceleration would be the friction generated at the mounting bushings which should be negligable. That is unless you have a car that is uneven and the sway bar is preloaded at static height.

How will it be lower? How will more weight be transferred to the rear of the car under longitudinal accel because of the sway bar?

So explain to me why you think taking out the anti-squat will really do that much? And how much anti-squat is designed into the rear suspension? I mean do you have real reasons for thinking any of this? Like quantifiable data saying that it's that big of a problem. You seem like a real proponent against anti-squat without really understanding what it does.

Don't get me wrong, I'm not saying that anti-squat is good, but it's not necessarily bad either. It's just another geometry effect that needs to be factored in. So give me some real reasons to back up what you're saying here.


I think a stiffer front bar is better because a good amount of successful autocross cars run a stiff front bar with no (or a stock) rear bar. It works and there is no denying that. What makes you think that a softer front sway is any better? You have yet to explain that. I am operating on one major, but most likely correct, assumption when I state that the cusco bar is stiffer. The cusco bar is almost certainly made of higher quality steel than the godspeed one. Also the godspeed bar is only 2mm thicker than the cusco bar and with that much longer of a moment arm I don't see how it could possibly be stiffer.

Basing a setup off of other people's successful setups is not always a bad idea, but a lot of people don't know how to set up a car to begin with. And it's autox, those guys run all kinds of weird stuff to try and get an advantage in some way through their little parking lot courses.

Anyway, a sway bar transfer load across the axle, it will take load away from the inside wheel and load the outside wheel. So while it stops body roll, it also increases load transfer to the outside wheel. If you look at the load sensitivity of tires, you will see that the coefficient of friction of the tire falls off as the load increases. So the lateral force capacity for a tire carrying all of the axle's load is less than the lateral force capacity for a 2 tires evenly carrying the load. So 2 more evenly loaded tires are better for higher lateral force.

And with even stock sway bars contributing to a large percentage of the total roll rate at the front, it's just transferring the load to the outside tire and hurting the total amount of lateral force that can be produced. I don't remember the numbers off of the top of my head, but I think the stock front sway is about 50% of the total roll rate when paired with a normal coilover setup. It might be a little less than that, but it's still really close. And stiffer bars are even worse.

As for the Cusco versus godspeed stiffness. You're major assumption is flawed. Go look up the shear modulus for cheap steel and high quality steel. They aren't very much different. So in terms of stiffness, as long as they're both steel, it's not going to be any different. Fatigue life will be effected and the longer term effects, but just in terms of strength that will not be. And you also don't know the wall thickness, which is a huge part in how stiff a torsion tube will be.


Of course the set-up differences are in the details, but driver preference does make a difference.

In my opinion, the car should be set up and dialed in by someone that knows what they're doing and then small driver preference issues can be factored in. I think too many people get used to bad setups because they claim it to be driver preference and when most drivers don't know what a good car is supposed to feel like their preference doesn't matter. They should be working to learn how to drive a properly set up car rather than possibly degrading the car to make it feel like something their used to. I'm not saying that the driver should be made uncomfortable, but like I said before, the driver is just another part.


I was driving the car harder this last event than the previous one at that track. I was picking up the throttle earlier and going full throttle instead of partial. The lines were exactly the same except in the re-paved section as I no longer had to straddle the split in the pavement. I have no inner drifter my friend, I am a driver to the death. You say that you are not trying to criticize my driving in the paragraph below, but it sure sounds like you are. I have been driving since I was a little kid, starting with a go-kart, and have always been one of the fast guys. That is not to say that my driving is perfect and I have nothing else to learn, just to say that the driving is not the main issue. Maybe I'm conceded, but the driving has never been hard for me.

I'm not really criticizing your driving. Just your mixed review of what the car was doing. It seemed to be all over the place. Maybe it was just how you explained it. But from what you wrote, it sounded like there were a lot more issues there than just removing the rear sway.


Of course there is something wrong with my set-up! It starts with the tein flex coilovers. If I had 8611's and could actually make a difference in how the car handles with my shock adjustments, rather than just how it rides, I'm sure I could do a lot more fine-tuning. I really haven't played with the knobe very much on my flexes because I am pretty convinced that it is futile. Shock tuning is the final step in tuning the suspension as well as it will make the smallest difference in the car. Now don't get me wrong, I am not saying that shock tuning does nothing. I'm pretty sure "getting into it way to early" isn't the problem, figuring out how to make all the various parts and pieces work together is. It takes a lot of tinkering to get it right and I know that. The initial lack of rear grip problem was the stupid stiff godspeed rear bar, since I have removed that I have not noticed any significant rear grip problems at an actual racetrack.

From what you were saying, it sounded more like a spring issue than a damper issue. Although with the cheap dampers, they can contribute to weird effects when driving. 8611's will help, but only if you pick the right springs and bars to go with them. Otherwise the damper will now be the strong point and the springs could be holding you back. It's important to get the right balance to start and then fine tune it, otherwise you will just be chasing yourself.

[racepar1]

Sway bars by definition only affect roll. The only effects you would see in pure longitudinal acceleration would be the friction generated at the mounting bushings which should be negligable. That is unless you have a car that is uneven and the sway bar is preloaded at static height.

How will it be lower? How will more weight be transferred to the rear of the car under longitudinal accel because of the sway bar?

Without the rear sway There will be more load transfered to the outside rear with less resistance to suspension compression. More load and more compression means that the outside rear of the car will be lower than the rest of the car, since it is lower it will pick-up more weight and a small amount of the extra weight on the rear will end up on the inside tire too because it is impossible to transfer weight to only one tire, it always at least marginally effects the amount of load on the other tires. Maybe my logic is a bit flawed but I do know that the lowest corner of the car picks up more weight.

So explain to me why you think taking out the anti-squat will really do that much? And how much anti-squat is designed into the rear suspension? I mean do you have real reasons for thinking any of this? Like quantifiable data saying that it's that big of a problem. You seem like a real proponent against anti-squat without really understanding what it does.

Don't get me wrong, I'm not saying that anti-squat is good, but it's not necessarily bad either. It's just another geometry effect that needs to be factored in. So give me some real reasons to back up what you're saying here.

Once again I am basing it on real world set-ups that seem to work pretty well. The XS engineering R-32 has the anti-squat removed from the rear suspension and really helped the amount of rear grip. Also it is common for track s-chasis guys to switch to the s-15 subframe or to use the solid bushings with the spacers to adjust out some anti-squat. SOME anti-squat is a good thing, but I KNOW that the s-13 rear subframe has an absolutely stupid amount of anti-squat designed into it and that is one of the main reasons that s-13's are such good drift cars. All that anti-squat quickens the transition to on-throttle oversteer and I want to slow that transition. Now on a soild rear axle car anti squat is a VERY good thing as the torque response of the axle actually drives the tires into the ground and produces more grip. With independent rear suspension that is not so, it simply prevents compression which lessens the amount of total weight transfer to the rear tires.

I'm not really criticizing your driving. Just your mixed review of what the car was doing. It seemed to be all over the place. Maybe it was just how you explained it. But from what you wrote, it sounded like there were a lot more issues there than just removing the rear sway.

From what you were saying, it sounded more like a spring issue than a damper issue. Although with the cheap dampers, they can contribute to weird effects when driving. 8611's will help, but only if you pick the right springs and bars to go with them. Otherwise the damper will now be the strong point and the springs could be holding you back. It's important to get the right balance to start and then fine tune it, otherwise you will just be chasing yourself.

The car is actually nothing but consistent, the inconsistency that you are getting is from the different set-ups that I have tried. With each set-up the car was very consistent, just with a different balance for each set-up. It went from massive oversteer to controllable but still too much oversteer to basically no oversteer but just a bit of understeer. I really don't think my springs are a big problem. I am running 9k fr and 7k r springs. That is certainly not 100% perfect, but I'm pretty damn sure that I am in the ballpark. What I am figuring out is how to make it all work together and what adjustments do what and how much.

[S14SwimShark105]

Maybe I'm conceded, but the driving has never been hard for me.

Honestly, if driving has never been hard for you, you aren't pushing yourself enough, you aren't trying hard enough. If you were to ask a "professional" race driver if driving was easy I'm sure he'd say " HELL NO".It seems like you are limiting yourself mentally. Sure if we had this car part, this type of tire, this amount of tuning it would make us faster. But who cares about IF we had those things, put your mind to what you have and how you can improve it. I think the driver is very important. I always thought understeer and oversteer are driver errors *pertaining to road racing*. If you get either, you are overdriving the limit of the car and what it can handle and will only result in going slower.


I'm surprised no one has mentioned Swift Swaybars. You can't simply look at how thick a sway bar is from company to company and tell how it will perform. Some are sway bars are hollow, some are solid, some are steel and other materials. Like what Swift mentions on their website is they rate their swaybars in Torsion Rate instead of how big/thick a bar is.

Randall

[Forge_55b]

Corner weighted? Who the fuck corner weights their daily driver?

when i autox'ed i had my car corner weighted and aligned about every 3 months or so

[slider2828]

This is just going way overboard with the question being asked.... I would always suggest, have the guy try it.... All it comes down to is steering feel, rotation of the car, and traction....

Seriously I think the answer is try it first. If it doesn't work try something else... Suspension setting is an art hands down. You don't tell Van Gogh how to paint its an expression. Suspension tuning is not cheap and not something you can say I bolt this on and bolt that on and here WALLA done..... Just go drive and try it out... If there are bumps or quirks, then just remove and have someone check if stuff is blown.

Another point is if you feel somethign is wrong, then something is wrong. Do something about it, but overall just replace all the worn stuff and get the car NEW again with bushings and good maintenance and operation. I am sure everyone has seen cars with expensive as heck parts but drives like ass and leaks everywhere. If maintained right, I think the 240 is a great base that most will fail to handle very well due to its attitude.

Drive and change drive and change. Just do it.... Every car is different, every driver is different, no one can tell how come it feels like that know it for yourself is the only way....

[Forge_55b]

i was gonna say that too slider but i enjoyed the debate that was going back and forth lol

[luftrofl]

Sway bars by definition only affect roll. The only effects you would see in pure longitudinal acceleration would be the friction generated at the mounting bushings which should be negligable. That is unless you have a car that is uneven and the sway bar is preloaded at static height.

How will it be lower? How will more weight be transferred to the rear of the car under longitudinal accel because of the sway bar?



The softer rear sway bar would allow for more roll and therefore more compression of the outside rear spring. This compression would be greater than that which would be allowed by a stiffer rear sway bar. Wouldn't the former setup with the lower rear (assume front compression is unchanged) result in more weight on the rear wheels? :confused:

[racepar1]

Honestly, if driving has never been hard for you, you aren't pushing yourself enough, you aren't trying hard enough. If you were to ask a "professional" race driver if driving was easy I'm sure he'd say " HELL NO".It seems like you are limiting yourself mentally. Sure if we had this car part, this type of tire, this amount of tuning it would make us faster. But who cares about IF we had those things, put your mind to what you have and how you can improve it. I think the driver is very important. I always thought understeer and oversteer are driver errors *pertaining to road racing*. If you get either, you are overdriving the limit of the car and what it can handle and will only result in going slower.

When I say "not hard" I am talking about picking up the line, finding my braking points, feeling the limit of grip before I spin off the track, etc.... Really pushing a car to it's limits is extremely difficult. It requires 100% of your concentration all the time. At the end of a track event I don't want to drive anywhere for at least a day because my mind is sooo damn over it! LOL! Ya know what I mean? I have generally found that when you relax a bit and just drive the damn car rather than really trying to push it you pick up a bit of time because like you said you are not overdriving the car.

I'm surprised no one has mentioned Swift Swaybars. You can't simply look at how thick a sway bar is from company to company and tell how it will perform. Some are sway bars are hollow, some are solid, some are steel and other materials. Like what Swift mentions on their website is they rate their swaybars in Torsion Rate instead of how big/thick a bar is.

Randall

I honestly didn't know that swift made sway bars, I'll have to look into that. Good suggestion.

[racepar1]

Well, I just checked out the swift sways. They are only available for s-14 and s-15 and I think the rear rate increase is too much. The front is a 49% increase in rate and the rear is a 79% increase in rate. I think that is more than I would want, although the s-14 and 15's don't have as much of a problem with rear traction so maybe not.

[Wiisass]

Without the rear sway There will be more load transfered to the outside rear with less resistance to suspension compression. More load and more compression means that the outside rear of the car will be lower than the rest of the car, since it is lower it will pick-up more weight and a small amount of the extra weight on the rear will end up on the inside tire too because it is impossible to transfer weight to only one tire, it always at least marginally effects the amount of load on the other tires. Maybe my logic is a bit flawed but I do know that the lowest corner of the car picks up more weight.

It works the other way. The stiffer end takes more load. Think of how adjusting sway bars affects the chassis. If the car is tight, you soften the front to give it more grip, which means that the front end will be more evenly loaded and that it will shift the total lateral load transfer distribution more towards the rear. The stiffer end transfers load faster. If you remove the rear sway bar, it decreases the total lateral load transfer at the rear, so that means less load on the rear during cornering.

The lowest corner only picks up more weight on banked surfaces. If you're corner balancing a car, you raise the corner to add weight to it.

And again, weight transfer is a function of accelerations and cg height and vehicle dimensions. It doesn't matter how much the wheel travels or what happens. It doesn't mean more weight. For lateral accelerations, you can adjust the distribution between the front and rear, but the overall weight transfer remains the same.


Once again I am basing it on real world set-ups that seem to work pretty well. The XS engineering R-32 has the anti-squat removed from the rear suspension and really helped the amount of rear grip. Also it is common for track s-chasis guys to switch to the s-15 subframe or to use the solid bushings with the spacers to adjust out some anti-squat. SOME anti-squat is a good thing, but I KNOW that the s-13 rear subframe has an absolutely stupid amount of anti-squat designed into it and that is one of the main reasons that s-13's are such good drift cars. All that anti-squat quickens the transition to on-throttle oversteer and I want to slow that transition. Now on a soild rear axle car anti squat is a VERY good thing as the torque response of the axle actually drives the tires into the ground and produces more grip. With independent rear suspension that is not so, it simply prevents compression which lessens the amount of total weight transfer to the rear tires.

So where's this data on the XS car? I'm not sayin that you're wrong, I just would like to see it for myself. Did they make any other changes at the same time that might have affected it as well?

So what qualifies as an absolutely stupid amount of rear squat?

There are some benefits of anti-squat. It helps to control the pitch attitude of the car. It can help to control the camber under acceleration because there will not be as much camber gain due to less travel. It will also transfer weight quicker, which you were right, it is good for drifting. But it can also be good for road racing if the suspension is properly setup. With the right tires and the right dampers and spring, you can take advantage of this quicker load transfer. I know you will say that because of the anti-squat the spring and damper do not compress as much, but you have to remember that there are forces from two different directions, both from the CG and from the road.

And again, compression does not equal load transfer. Repeat it, remember it, learn it.

The car is actually nothing but consistent, the inconsistency that you are getting is from the different set-ups that I have tried. With each set-up the car was very consistent, just with a different balance for each set-up. It went from massive oversteer to controllable but still too much oversteer to basically no oversteer but just a bit of understeer. I really don't think my springs are a big problem. I am running 9k fr and 7k r springs. That is certainly not 100% perfect, but I'm pretty damn sure that I am in the ballpark. What I am figuring out is how to make it all work together and what adjustments do what and how much.

But could it be better? People always clain there car is good and drives well, but it can always be better. Your springs may be alright, but it really depends on weight distribution and roll center heights and a variety of other things. There's a lot that goes into it, but you might be close.



This is just going way overboard with the question being asked.... I would always suggest, have the guy try it.... All it comes down to is steering feel, rotation of the car, and traction....

Seriously I think the answer is try it first. If it doesn't work try something else... Suspension setting is an art hands down. You don't tell Van Gogh how to paint its an expression. Suspension tuning is not cheap and not something you can say I bolt this on and bolt that on and here WALLA done..... Just go drive and try it out... If there are bumps or quirks, then just remove and have someone check if stuff is blown.

Another point is if you feel somethign is wrong, then something is wrong. Do something about it, but overall just replace all the worn stuff and get the car NEW again with bushings and good maintenance and operation. I am sure everyone has seen cars with expensive as heck parts but drives like ass and leaks everywhere. If maintained right, I think the 240 is a great base that most will fail to handle very well due to its attitude.

Drive and change drive and change. Just do it.... Every car is different, every driver is different, no one can tell how come it feels like that know it for yourself is the only way....

Suspension tuning isn't really an art. It may be for people who don't understand it. But when you do, it's more of a science than anything else. There are some educated guesses, but they're based on a lot of experience and research. And there is a right way to set up a car and a wrong way. People will do it the wrong way and blame something else on it.

Depending on how much design goes into a setup and how good the numbers you are basing it on, you can be very close to where the car should be without having to test it over and over again. It will never be perfect the first time, but I guarantee with good design and thought put into the setup, you will be closer than any of the off the shelf stuff.

Driving and changing gets expensive and some people can't afford to try a setup and then sell it if they don't like it and buy another one. It's just not time or cost effective. Figuring out what they want out of a setup and doing the best to pick the right parts the first time will really go a long way.


The softer rear sway bar would allow for more roll and therefore more compression of the outside rear spring. This compression would be greater than that which would be allowed by a stiffer rear sway bar. Wouldn't the former setup with the lower rear (assume front compression is unchanged) result in more weight on the rear wheels? :confused:

Nope. Read above.

And just in case, again, more compression does not mean more load.



Tim

[luftrofl]

And just in case, again, more compression does not mean more load.


That may be true but I'm talking about weight, not load. When the rear end is lower than the front (eg while under compression), the center of gravity shifts to the rear- thus more weight is on the rear.

I've spent 1000 billion hours in my high tech photo editing software to illustrate this. Please assume that the compression is a bit more realistic and that the wheels are actually touching the ground. I've obviously exaggerated these aspects. Just take note of how the center of gravity shifts toward the rear when the rear end is lower than the front(The CoG is the red dot, if you couldn't tell from the genius drawing :keke: )

http://img356.imageshack.us/img356/7421/weighttransferxf9.jpg
http://img356.imageshack.us/img356/7421/weighttransferxf9.jpg

[Wiisass]

You guys are all over the place. You talk about roll and then you talk about pitch. They're different and have different loading conditions.

And weight is load, load is weight. It's the same thing.

You said in roll, with no rear sway bar, the spring will compress more. This is true because there is no additional roll rate from the sway bar. But more spring compression does not mean more load on the outside rear wheel during roll. It means less because the total lateral load transfer distribution would now be biased more towards the front of the car.

What you said was like trying to say that because a 100lb/in spring compresses 10 inches with 1000lbs on it, it has more load than a 500lb/in spring that compresses 2 inches with the same 1000lbs on it.

And your drawing is not wrong, it's just not applicable. I understand it is exaggerated, but you under normal conditions, the car does not pitch that much and the change in CG movement is very low. And it does not contribute much to the actual wheel loads.

The change in wheel loads is a function of acceleration on a mass because F = ma. The magnitude of this force depends on the dimensions of the vehicle and the height of the CG. Under longitudinal acceleration, it is usually splot pretty evenly between the front or rear wheels. Under lateral acceleration, it is split based on the distribution of the roll rates and suspension geometry differences.

[luftrofl]

Sorry, I meant weight transfer. Weight transfer and load transfer are similar, but not the same. Short of wikipedia, I can't find anything online to cite for my point.

You asked "How will it be lower? How will more weight be transferred to the rear of the car under longitudinal accel because of the sway bar?" and I showed you and you agreed (albiet not to the extent that I'm saying).

I do think that weight transfer due to a shift in the CoG is made insignificant as shock travel decrease, ride height decreases, and springs become stiffer. Weight transfer due to a shift in CoG can, however, remain significant at the ride height that our 240s have.

Edit: In your spring example, I'm not saying that there is greater load on the softer spring, but rather that the softer spring will cause the CoG to shift to the rear and put more weight on the rear.

[Wiisass]

Alright, so you're not getting it.

So what's your point about load transfer and weight transfer being different? Are you just trying to say that load transfer is based on forces at the CG and weight transfer is based on the change in wheel load due to the change in CG position due to chassis movement? Is so, it's really not applicable.

So how are you misreading my statements? When I said "How will it be lower?" it was in reference to lower than with a rear sway. And since we were talking about longitudinal acceleration, the rear sway doesn't really play a part there. So there would be the same load transfer to the rear with or without a sway bar. So there will not be more weight (meaning more than with the rear sway bar) on the rear of the car under longitudinal acceleration.

This is just more of you guys switching between lateral and longitudinal accelerations. I don't know if you just don't realize what you're doing or if you're just trying to prove a point without enough info. But anyway, keep the difference between lateral and longitudinal accelerations in mind.

Anyway, if you really think the CG position is going to change things that much, then run the numbers and prove it. Assume a 2500lb car, 18 inch CG height, 97.4 inch wheelbase, 53% front weight distribution, 240lb/in ride rate. And then tell me what you come up with. If you come up with the same answer that I did, you will realize that the longitudinal displacement of the CG will be very low.

Even if you use stock numbers, it's not going to be that great of a change. Run the numbers and you will find out. You can even use stock numbers if you want, or the numbers I posted above. But run them and prove how significant it is or find out that it's really not.

[racepar1]

Since the suspension is compressing more it will not only just roll, but also pitch. That is our point. With no rear sway the outside rear compresses more which not only increases roll, but also pitch. If you average out the amount of suspension compression (side to side) and compare the numbers between the front and rear with and without the rear sway the average rear compression with the rear sway will be less than without it, so there is also more pitch. More pitch means more overall weight transfered to the rear, which means more traction. I am not saying that we're necessarily 100% right, just trying to explain what we're talking about in the fancy "engineering" terms that you seem to need to hear to be able to understand. You know there is such a thing as overengineering right dude?

[Wiisass]

It will not increase pitch. How do I have to explain this for you to understand it?

Alright, so let's compare, with or without a rear sway bar. For roll, the rear is stiffer with the rear sway bar and takes more of the lateral force because of this, it also rolls less because the car is stiffer. Without a rear sway, the roll rate is lower, the car takes less of the lateral force and the car rolls more.

For pitch, with or without a rear sway, does not matter. It has the same pitch stiffness whether or not there's a rear sway on the car.

So I've been breaking this down between lateral and longitudinal accelerations to make it easier to understand. But it seems like you really want to talk about a mixed loading condition, like corner exit. You realize that this loading scenario is more complex and if you guys are understanding what I'm saying when we're talking about one acceleration, how are you going to follow with two?

And didn't I already say, that more pitch or more roll does not equal more load? Or did you miss that part?

But where is this pitch coming from? Are you trying to say that under roll the angle in the horizontal plane will be different depending on what rear sway is on the car? So you're trying to make the same point the last guy did. And say that because the car may be tilted back a little more under roll with no rear sway, that there is more weight on the back? You guys should run those numbers, then you will see how little of an effect small angles of body attitude have on the CG position. And without longitudinal accelerations, the weight transfer from the front to the rear will be negligable.

If that's what you're trying to claim as you being right, then it's not that you're wrong, it's just so small of a difference that it does not matter. Run the numbers and you'll see. What you're trying to say with that point, is like saying that you shouldn't let your rear tires wear because it will change your final drive ratio. Which, while it is true, is so small of an effect that it can be ignored.

But if you're talking about a situation like corner exit and you're comparing two cars under the same loading conditions. Even if you assume 1g lateral and 1g longitudinal, the car without the rear sway will have less load on the outside rear wheel than the car with the rear sway. You have your load transfer from roll and your load transfer from pitch. And since your load transfer from roll is less without the rear sway and your load transfer from pitch will stay the same, you will have less load on the outside rear wheel.

And feel free, if you guys want to, figure out the load transfer from the CG position change. If you really want to prove your point, then post your calcs and the results. I mean, since you don't seem to believe that it will be a small number that won't mean anything. Prove that is will mean something.

So please, post some facts or data or calculations, that show that you're right. And sorry about using the proper terminology to describe what's happening. It helps to keep people from getting confused and makes the message easier to understand. And these are all basic terms that anyone who thinks they know about racing and motorsports should easily be able to understand.

And there is a such thing as overengineering, that's not what this is at all. But you need to know that there is also such a thing as not fully understanding a concept.

[MrChow]

aahhh.. Sooo much reading... lol, if read the words weight transfer again I'm shooting something... =o

But if you're talking about a situation like corner exit and you're comparing two cars under the same loading conditions. Even if you assume 1g lateral and 1g longitudinal, the car without the rear sway will have less load on the outside rear wheel than the car with the rear sway. You have your load transfer from roll and your load transfer from pitch. And since your load transfer from roll is less without the rear sway and your load transfer from pitch will stay the same, you will have less load on the outside rear wheel.
I know what your talking about here. I never knew how to explain that feeling but now I do. =o

[racepar1]

Wisass: You finally got to talking about what we are talking about, dynamic load transfer where there is more than just one force acting on the chasis. What a car does on a piece of paper in a "perfect" mathematical world does not translate directly to what happens to the car on the track. Like I said we are not necessarily right, but we are now all talking about the same scenario. I can see that the inside tire would become unloaded without a rear sway, but then why does it stick so good? With the inside tire unloaded it should lose rear grip, not gain it. But I can assure you that it did gain rear traction, actually just a bit too much rear traction. I decided to re-install the stock 15mm rear sway and see if that brings the balance of the car to where I am happy with it.

[luftrofl]

And feel free, if you guys want to, figure out the load transfer from the CG position change. If you really want to prove your point, then post your calcs and the results. I mean, since you don't seem to believe that it will be a small number that won't mean anything. Prove that is will mean something.



I did the calculations while bored on a plane. I'll concede that while weight transfer due to CoG shifting longitudinally due to the sway bars under lateral acceleration does happen (and isn't that what I was trying to say originally? :angel: ), it's much less than I thought it'd be. Hooray for thinking that the CoG was higher than it could be :aw:

IIRC, for my calculations, I used a car with the following details: 2.5m wheelbase, 1m track, 0.5m high CoG, 1000kg mass, lateral acceleration of 2.5m/s/s.
In the end, about 100N (or 10kg or 22lb). ended up going to the rear due to the lateral acceleration alone-not as high as I thought it'd be. This was a very rough figure and I'd actually doublecheck my calculations if it really mattered.

Edit:
I can see that the inside tire would become unloaded without a rear sway, but then why does it stick so good? With the inside tire unloaded it should lose rear grip, not gain it. But I can assure you that it did gain rear traction, actually just a bit too much rear traction.

Too much load on the outside, probably. The inside rear picks up some of the load when there's a weaker/no rear sway bar. These two events result in more grip.

[Wiisass]

Well maybe you guys need to be clear in what you're actually talking about. For the most part, it sounded like you were talking about the effects of the sway bar on longitudinal acceleration and the effects of anti-squat on lateral accelerations.

And I was trying to simplify it for you guys. You have to understand each loading scenario before you can accurately picture a more complex situation.

And if your model is good, you can get a very good approximation on paper of what a car will do on the track. Depending on how good the model is, the biggest variable will be the driver. But with a good driver, the model and real life are very easy to correlate and then you can save a lot of money and time. At least that's how every real race team does it.

So who said the inside tire would become unloaded without a rear sway? I said there would be less lateral weight transfer without the rear sway, that means that the inside tire would have more load it and the rear would be more evenly loaded than with a rear sway.

And Luftrofl, what numbers did you use for stiffnesses with and without a sway bar? And roll center heights? With the numbers you posted, I don't see how you could get anything really representative of what is actually happening.

But I guess you at least did some kind of calculations that showed you that the CG position does not move enough to cause any relevant change in wheel loads. And I never said that it didn't, I just said it was so small that it was negligable. Like I said, you weren't wrong, it just didn't matter.

[racepar1]

So who said the inside tire would become unloaded without a rear sway? I said there would be less lateral weight transfer without the rear sway, that means that the inside tire would have more load it and the rear would be more evenly loaded than with a rear sway.

If the rear tires are more evenly loaded without a rear sway then why is is so stupid to run without one? S-13's are NOTORIOUS for having problems with rear traction. This whole conversation started when you said that it is a bad idea to run without a rear sway bar, but in the above statement you just contradicted yourself. More evenly loaded tires = more rear grip, which is a major issue on s-13's, therefore no swaybar = better.

[luftrofl]

And Luftrofl, what numbers did you use for stiffnesses with and without a sway bar? And roll center heights? With the numbers you posted, I don't see how you could get anything really representative of what is actually happening.



I don't remember the exact values. I do remember, however, that they were realistic. The sway bar in the front was pretty damn stiff and there was no rear sway bar.

[Wiisass]

If the rear tires are more evenly loaded without a rear sway then why is is so stupid to run without one? S-13's are NOTORIOUS for having problems with rear traction. This whole conversation started when you said that it is a bad idea to run without a rear sway bar, but in the above statement you just contradicted yourself. More evenly loaded tires = more rear grip, which is a major issue on s-13's, therefore no swaybar = better.

I feel like I'm talking in circles.

But anyway, I said that I think that no sway bar in the back is not the answer. I like a soft sway bar back there, just enough to give you the roll rate that the car should have and enough to be able to use it to adjust the balance of the car. No sway bar would keep the tires more evenly loaded. But you also have to consider camber gain and bumpsteer and balance and desired roll gradient and a bunch of other things.

Just removing the rear sway bar, makes the rear of the car too soft in roll and too understeer biased especially because people seem to think that a stiff front bar is a good idea. By running a stiff front bar and no rear sway, you're making the front take too much of the lateral load transfer. And since there's more than just one axle on a car, that's important.

When it comes to suspensions, you can't just consider one part, you have to look at it as a whole. Each part contributes to the rest of it. There are some compromises that need to be made and some parts and design goals take priority over others, but you still need to look at the big pictures. If you look at like you just stated in that post, you'll never figure it out.

I don't remember the exact values. I do remember, however, that they were realistic. The sway bar in the front was pretty damn stiff and there was no rear sway bar.

So give me a ballpark on what's realistic. I mean if you have all the installation ratios and roll center heights and all of that, then you can come up with a very good approximation. But because you approximated the track at 39" when it's a good bit wider than that, makes me think that your numbers were not right.

[luftrofl]

So give me a ballpark on what's realistic. I mean if you have all the installation ratios and roll center heights and all of that, then you can come up with a very good approximation. But because you approximated the track at 39" when it's a good bit wider than that, makes me think that your numbers were not right.

Oh, I didn't base it at all on 240s. I just picked some numbers that I thought would be easy to use for the purpose of illustrating a point, not winning a nobel prize, while maintaining somewhat realistic forces. :bite:

I want to say 150N/mm for the front sway bar... and I think that I put the roll center @ 300mm off the ground.

I saved it on the borrowed laptop I was using so I can probably dig it up.

Did you calculate it out for the 240? I'd be interested to know what you got.

[racepar1]

Wow this has gotten silly now. Wisass The whole point of running a stiff front sway and a soft or no rear sway is to change the balance of the car more towards understeer. That is exactly why people run that set-up. 240's, especially s-13's, are far biased towards oversteer at the limit especially on the throttle. You started off by arguing against the above mentioned sway bar set-up and now you confirm that it does EXACTLY what it is supposed to. Hell I can tell it is overloading the outside front tire off the throttle just by what the car does on the track, I don't need a bunch of numbers to tell me that. The fact that the car handles perfectly as soon as I even touch the throttle, because it transfers some of the load to the rear, tells me that the front is overloaded. I am pretty certain that with the progress adjustable front sway and 8611's I could tune the car to work pretty much perfect with no rear sway. I would have to run the sway bar probably in the middle position, change the alignment some, and use the shocks to slow the weight transfer to the front of the car and encourage weight transfer to the rear (stiff front compression/soft front rebound, soft rear compression/stiff rear rebound, relatively speaking of course). Why would we concentrate on the sway bars alone for lateral acceleration and anti-squat alone for longitudinal acceleration? Those two things work together and where on the track are you only going to have lateral or longitudinal accel/decel? There is ALWAYS more than one force acting on the car on the racetrack. I think the problem here is that we think differently. You are thinking of what a car does on a piece of paper whith whatever force you decide to apply to it. I am thinking of a car on a racetrack whti multiple forces applied to it in constantly varying amounts. Since we don't think the same we seem to end up in totally different places.

[nisans13turbo]

It depends on the sway bars. 240's like to have no rear sway or a stock rear sway combined with a beefy front sway for the track. This is due to the eccessive amounts of anti-squat in the rear suspension, especially on the s-13's. Running a soft rear sway or none at all helps transfer more weight to the rear of the car and keep the ass planted coming off the corners. It will give the car slightly more understeer off the throttle, but that can be tuned out of the car using other suspension adjustments. For a beginner it is better to have a car that has a small amount of understeer anyways as the car is more stable and consistent. For drift you want thicker front and rear bar as it will quicken the transition to on-throttle oversteer. Most 240's came with 24mm front and 15mm rear sway bars, I have also seen 25mm front bars and 17mm and 21mm hollow (hicas/jdm) rear sway bars that came from the factory too (those are for the s-13, IDK about the s-14's). That is a difference of 9mm between the front and rear bars. Making that difference smaller or larger is what will affect the balance of the car.

So would you recommend godspeed f/r swaybar for drifting and drifting only?

[LA_phantom_240]

The Godspeed bars are crush bent rather than mandrel bent, right? If so, I wouldn't really recommend them because you're losing stiffness through the shitty bends, and the thicker bar makes up for it, which means more weight.

I've been told the Cusco bars are nice.

[nisans13turbo]

actually its mendrel bend.

[tschad]

im jus curious. wat 240 is best for handling.
s13 coup
s13 fb
or s14?

[tschad]

im just curious. wat 240 is best for handling?
s13 coupe
s13 fb
or s14?

[LA_phantom_240]

S14s have more neutral handling, with the S13 tending to oversteer. Unfortunately, the S14 is heavier than the S13... but I love my s14's road manners much more than any s13 i've had.

[nisans13turbo]

im just curious. wat 240 is best for handling?
s13 coupe
s13 fb
or s14?

For the s13, I was told coupe would be better at handling assuming its body structure, more metal compare to fastback, fastback has 3 large windows in the back.

About the mendrel bend on the godspeed, i just took a quick glance at mine, but I will verify it but im sure its not crush bent.

[OptionZero]

im just curious. wat 240 is best for handling?
s13 coupe
s13 fb
or s14?

the differences are negligible given that the build will produce far too many variables

and to be an asshole

if you need to ask, it probably doesn't matter

[LA_phantom_240]

the differences are negligible given that the build will produce far too many variables

and to be an asshole

if you need to ask, it probably doesn't matter

lol.:ddog: