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-   -   This is the roll center, suspension pickup, and steering angle modification thread. (#/f/showthread.php?t=296725)

Def 12-30-2009 01:19 PM

Quote:

Originally Posted by PoorMans180SX (Post 3209841)
They were talking about the URAS ones, which are a different design and less quality.

Driftworks designed theirs to be better.

I'll quote:

It doesn't matter how much "better" they design the materials, that part still puts the steering rack into bending when it wasn't designed to handle that(inner tie rods pivot, and it doesn't locate the front spindle at all, so no bending). The rack might handle it for a bit, but I imagine the seals aren't up for that kind of beating.

white92_s13 12-30-2009 06:56 PM

i have a few question just pertaining to basic angles and mods.

So I have a corolla and i have played with angle a little bit.

My first setup was some steering rack spacers, stock inners and megan outer. ran great got good angle. and to correct the roll center i used battle version NRCA.

so now i have a fresh chassis to play with.

I want to get MORE angle by modifying some stock knuckles.

MY idea.....?
take a stock knuckle off. take a pre measured chunck out. not much. and then heat it with a torch and weld it back together. shortening the knuckle with increase the leverage and gain more angle?

so with shortened knuckle length, megan tie rod ends, battle version roll center adjusters, t3 camber plates, and some battle version steering rack spacers, a fresh alignment i should have a good angle setup? in theory should be more then i had before with not having shorten'd knuckles.

i dont have to worry about the tie rod hitting the lower control, and i already have my roll center adjusted with the battle version nrca.

PoorMans180SX 12-30-2009 08:10 PM

Quote:

Originally Posted by Def (Post 3210092)
It doesn't matter how much "better" they design the materials, that part still puts the steering rack into bending when it wasn't designed to handle that(inner tie rods pivot, and it doesn't locate the front spindle at all, so no bending). The rack might handle it for a bit, but I imagine the seals aren't up for that kind of beating.

Good to know. I guess the only way to correctly do this is to actually move the rack forward. Fabrication time.

mmdb 12-30-2009 09:02 PM

Another FYI (sorry i know). I'm using the GP Sports Hyper knuckle right now, and because it spaces the lower control arm and the spindle it added a bit of negative camber. It's likely that during compression the front suspension cambers inward, and by fixing the roll center it's added much negative camber. This could take a toll if your camber plates are out of adjustment which doesn't allow you to run less negative camber. Currently I'm stuck running 1.8' negative camber and out of adjustment.

PoorMans180SX 12-30-2009 09:50 PM

Quote:

Originally Posted by mmdb (Post 3210838)
Another FYI (sorry i know). I'm using the GP Sports Hyper knuckle right now, and because it spaces the lower control arm and the spindle it added a bit of negative camber. It's likely that during compression the front suspension cambers inward, and by fixing the roll center it's added much negative camber. This could take a toll if your camber plates are out of adjustment which doesn't allow you to run less negative camber. Currently I'm stuck running 1.8' negative camber and out of adjustment.

Found this in a Sport Compact Car article:

Quote:

Originally Posted by Sport Compact Car
On MacPherson strut-equipped cars, the wheel will gain negative camber under roll as long as the lower control arm is positioned less than 90 degrees relative to the strut axis. Unfortunately, many enthusiasts with MacPherson strut-equipped cars lower their cars too much and make this angle greater than 90 degrees. Beyond 90 degrees, the suspension will gain positive camber instead of negative as it compresses, significantly compromising grip

http://i24.photobucket.com/albums/c2...iondiagram.jpg

I don't know why it would be a problem, as gaining negative camber in a corner is good. Do you mean if you have already adjusted your camber plates to run a lot of negative camber, then correct your roll center, your car will run too much camber in corners?

Jonnie Fraz 12-30-2009 10:17 PM

Quote:

Originally Posted by PoorMans180SX (Post 3210912)
Found this in a Sport Compact Car article:



I don't know why it would be a problem, as gaining negative camber in a corner is good. Do you mean if you have already adjusted your camber plates to run a lot of negative camber, then correct your roll center, your car will run too much camber in corners?

This is a great graphic! I remember reading this series in SCC back before the mag went to shit.
This also explains why I have seen some of these super low cars running retarded front camber. That would also get the angle below 90.
I like changing the pick-up points better, but to each is own. Please keep filling this thread with great info.
One thing that I keep thinking about is with suspention set-ups as stiff as have been discussed earlier what kind of compession travel are we talking about?

mmdb 12-30-2009 10:46 PM

I can't hit more than 2.3' of negative camber. This is probably due to my shock manufacterer being partially misinformed, but it could be a potential problem for others as well. Another problem that could arise is the shock length. When the knuckle is raised the shock is also compressed. Shocks with a separate perch and preload adjustment will be ok.

s13silvia123 12-30-2009 10:56 PM

i should of started this thread years ago when i was curious about this and wanted to learn more back then.

VIPDRFT 12-31-2009 12:11 AM

I stumbled upon this. They make knuckles that look like the Driftworks ones. Flame away.

http://www.cens.com/cens/publication/9/512/56551_l.jpg

PoorMans180SX 12-31-2009 12:29 AM

Quote:

Originally Posted by white92_s13 (Post 3210649)

MY idea.....?
take a stock knuckle off. take a pre measured chunck out. not much. and then heat it with a torch and weld it back together. shortening the knuckle with increase the leverage and gain more angle?

Yeah, that should work, just be careful welding on cast iron, it's hard to get good penetration! Also, make sure the tie rod holes stay in the same position in relation to the knuckle, just moved in closer. This will keep your steer feel the same.

Quote:

Originally Posted by Jonnie Fraz (Post 3210943)
This is a great graphic! I remember reading this series in SCC back before the mag went to shit.
This also explains why I have seen some of these super low cars running retarded front camber. That would also get the angle below 90.
I like changing the pick-up points better, but to each is own. Please keep filling this thread with great info.
One thing that I keep thinking about is with suspention set-ups as stiff as have been discussed earlier what kind of compession travel are we talking about?

Hmmm...I would say about 4 inches, give or take a few? Most coilovers run 8/6, and cars roll very little with these and even stock anti-roll bars. Heck, most coilovers don't have more than 4-6inches of shock travel anyway.

I know with my 10/8 there was pretty much zero roll, and with my 12/10 there was absolutely no roll. But then again, this was with less-than-grippy tires.

Maybe the grip guys running slicks can comment on body roll a little more.

But anyway, part of the reason you run a stiff suspension is to reduce camber and toe change with body roll. So with a corrected roll center, this should allow you to run just a little less static camber. I guess it depends on how your strut is angled and how low your car is. Those guys running extended front lower brackets on their coilovers are actually at a disadvantage there; they make the angle greater.

Quote:

Originally Posted by VIPDRFT (Post 3211106)
I stumbled upon this. They make knuckles that look like the Driftworks ones. Flame away.

Taiwan? Making a knock-off?!?! What?!?!? Hahahaha.

mmdb 12-31-2009 12:44 AM

Quote:

Originally Posted by VIPDRFT (Post 3211106)
I stumbled upon this. They make knuckles that look like the Driftworks ones. Flame away.

The Taiwanese company could have copied a Japanese manufacturer initially; I know I've seen this before. Though, the design would be somewhat similar between manufacturers, the geometry might have changed. Anyway, I would rather have a part made in England rather than in Taiwan... but I guess it could go both ways (a part failing that is).

GripTerror 12-31-2009 04:58 AM

Driftworks GeoMaster Hub Knuckles - Drifting forum - Driftworks

SoSideways 12-31-2009 09:00 AM

Dang, 695 pounds for all 4... that's about the price of just the GP Sports front knuckles.

Good deal, but who imports their stuff?

GripTerror 12-31-2009 09:03 AM

Yeah I would hope someone imports this stuff as its gona be arm and a leg on customs/taxes rape as well as shipping. This is the most awesome part ever imo

scottie 12-31-2009 10:39 AM

They (DriftWorks) cant estimate shipping? I wonder who rhdjapan uses for shipping because their stuff wasnt that bad on shipping charges to be honest. I wouldnt be surprised if they can ship international through USPS for a fair price. I may need to email them about shipping international.

GripTerror 12-31-2009 12:01 PM

yeah but they charge arm and a leg on the product itself. I've bought from rdhjapan before... insane prices on stupid simple stuff just because its jdm... seriously... but they are friendly.

95KA-Turbo 12-31-2009 12:13 PM

I have a friend stationed in the UK, I don't see why he couldn't get the spindles shipped to him, then ship them out through the base USPS and get very reasonable rates on shipping.

SoSideways 12-31-2009 12:26 PM

Quote:

Originally Posted by 95KA-Turbo (Post 3211692)
I have a friend stationed in the UK, I don't see why he couldn't get the spindles shipped to him, then ship them out through the base USPS and get very reasonable rates on shipping.

Yeah but not everyone has a hook up in the UK for the purpose of shipping something.

I think what we were trying to get at is to have a more permanent solution to the shipping dilemma for Drift Works stuffs.

95KA-Turbo 12-31-2009 01:07 PM

Right, I should have worded it a little differently. If anyone is serious about wanting them I can talk to my friend.

roboticnissan 12-31-2009 01:11 PM

So the basic idea is to try to get all arms parralel with the ground while under load and keeping all arms as even as possible at the same time??

95KA-Turbo 12-31-2009 01:22 PM

Right, a more correct way of saying it might be - preserve the stock suspension geometry as much as possible.

I believe there are improvements that can be made to the stock geometry, but that is much more complicated then just correcting it back to stock. I figure if you make everything adjustable, you can tweak it at the track and get it set up for your own personal preference.

d0pe240 12-31-2009 06:12 PM

i was wondering would these greddy and moonface ball joints/roll center adjusters be enough to make the control arm straight enough for a slammed 240sx?

http://www.rhdjapan.com/media/catalo...mal/Image2.jpg

http://www.rhdjapan.com/media/catalo...mal/Image1.jpg

95KA-Turbo 12-31-2009 06:20 PM

No, at most those give 1/3-1/2 inch of adjustment.

The only ones that actually do anything are the top of the line Moonface ones....IMO 1/2 inch of adjustment isn't worth 450 bucks.

d0pe240 12-31-2009 06:33 PM

Quote:

Originally Posted by 95KA-Turbo (Post 3212158)
No, at most those give 1/3-1/2 inch of adjustment.

The only ones that actually do anything are the top of the line Moonface ones....IMO 1/2 inch of adjustment isn't worth 450 bucks.


yeh they didnt look long enough, like how your setup is. how much do you think your set up cost, just for the roll center adjusters?

PoorMans180SX 12-31-2009 06:41 PM

Remember, if they space the ball joint UP, then they don't actually do anything. The pivot point has to remain the same, the shank is what is supposed to be taller.

95KA-Turbo 12-31-2009 06:44 PM

Quote:

Originally Posted by d0pe240 (Post 3212183)
yeh they didnt look long enough, like how your setup is. how much do you think your set up cost, just for the roll center adjusters?

Since you have to ream the spindle to accept the shank I am using and weld parts to the LCA, it will have be a LCA + spindle package. I will talk to Danny and let you know. It should be pretty affordable compared to whats out there.

articdragon192 12-31-2009 08:07 PM

Pardon my ignorance, but what does overcentering mean? And why is it bad?

GSXRJJordan 12-31-2009 08:25 PM

Quote:

Originally Posted by articdragon192 (Post 3212278)
Pardon my ignorance, but what does overcentering mean? And why is it bad?

That's when you pass the point at which more side-to-side movement moves the knuckle out, and the knuckle comes back in - then you go to turn the other way and the tie rod is stuck. Hard to explain, hopefully that gives you a visual.

udon! 12-31-2009 08:33 PM

so for a basic (begginer) roll correction setup on a slammed 240sx you would want inner/outer tie rods, tension rods, and the ruca and rear toe rod?

sorry im a little new to the suspension stuff...

articdragon192 12-31-2009 08:34 PM

Ahhh, I got it now. Ok makes sense.


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