Let's hunt the perfect SM setup... S13/S14

[HaLo]

Hey guys!

How many of you SERIOUSLY auto-x? I am curious. I want people to share their info to find the BEST tire / suspension setup for a DSP or SM 240sx. I am a bit disappointed to see that for 2 consecutive years, NO 240sx were at the Nationals at Topeka.

Our enemy? SM Supercharged M3s, SM Civics...

First of all, what are you guys running, what are you settings and what are the pros/cons of your setup?

Suspension:
D2 Coilovers with camber plates 7/5
Urethane TC rod bushings
Front and rear STBS
-2.3 deg in front, -1.8 deg in rear
Hicas

Tires:
Yokohama A032R, 225 front, 245 rear

Pros:
Seems very neutral, has little body roll. Very predictable steering.

Cons:
Seems to understeer at the limit.

To improve my setup, I plan on:
getting 245 ALL around
getting sway bars (whiteline)
getting more camber, -3 in front.

With my current setup, I did 2 top 3 finishes in my 2nd year, was 4th in standings before my engine blew.

What about you?

[thx247]

Never had a chance in SM around here. You can thank Vic Sias for that.

I think you might be ok just using a larger bar in the rear (Whiteline) of your car and even wheels all around.

[LanceS13]

I think I've missed one local autocross in 3 years and attend about 6-8 out-of-region autocrosses a year...so, yeah, I guess I'm pretty serious.
I've done well in DSP...Mississippi PAX Champion 2002 and 2003...working on 2004. I attribute that partly to the "easy to be the big fish in a small pond" theory. But I win or do well in a lot of out-of-region events, too...and I can usually keep up with John Thomas in PAX when he visits.
But I just bumped myself to SM with RUCA's and adj. tie rods...but with basically a stock engine at the moment (i/e).
My DSP setup probably wasn't the best, but it worked ok. I drove around the underdamped AGX with KGMM SS springs. -2/-1 camber, 0/0 toe, whiteline bars at full stiff front/full soft rear, and 225 Victoracers. I've gotten pretty good at inducing oversteer with left foot braking. I rarely had understeer problems. Slow/tight coners on wet/gritty surfaces would cause understeer, but that could be attributed to taking the corner too hot for the conditions and the lack of lsd.
I'll be tuning my new KTS coilovers and the rest of the suspension for the rest of the year. Actually having decent damping should make the car even better. I'm trying to get an LSD in the car, too.
I think a good driver in a properly developed 240SX could do well in DSP or SM at Nat'ls.
My plans over the next couple (several?) years are:
-finish my KAT and put it all in.
-all adjustable control arms to help alleviate the front roll center problem and solid bushings everywhere to eliminate compliance.
-basic 6pt. cage to stiffen things up and give me something to tie myself to.
-anything I can do to legally lose weight (c/f hood, remove backseat, 1pc seats, etc.)
-cram some 275's into the fenders.
-take it to Nat'ls by 2006 whether it's finished or not.
I think it could be every bit as competive as the current SM dominators.
BMW=big power (~400hp) but heavy (~2900lb)
Civic=less power (~250hp) but light (~2200lb)
240SX=decent power (~320hp) but not that heavy (~2600lb)
And there really isn't any inherent disadvantage (that can't be fixed w/i the SM rules) that I can see in the overall design of the 240 compared to these cars. But the M3 and Civic don't really worry me...I'm waiting for somebody to find a decent RWD chassis that weights the 2400lb minimum weight, cram a 3L f/i engine in it, and develop the suspension. The first thing that pops to mind is a Supra TT-powered AE86...don't know if that swap is possible, but you get my point.

[HaLo]

Actually, SM M3s have been know to lower their weight down all the way to 2600 lbs with aluminium doors and other things.

Why isn't there more serious Auto-x drivers going around in 240sx? There is 3 240s in the whole Quebec province, and I can only say 2 of them are serious about it. I plan to do nationals some day, but I need to find the right setup. And the right setup is mostly a suspension thing.

[nocomedown]

i'm trying to get into it seriously, but it's not easy when you're 900 miles away from your car :(
i'll hopefully be tailoring it to AutoX when i go back home this summer

[AceInHole]

Umm.... i'm sort of serious about autox i guess. I go to a *few* events per year.

My next year's setup (if it's done in time. If not, I'm running STS in a Civic HX):

Engine:
KA24DET (sorry Halo) at around 350rwhp
7300 RPM redline

Drivetrain:
Unknown 6 puck sprung clutch
J30 VLSD (in much need of a Quaife. 250rwhp kills the J30. adding more power won't help that much)

Suspension:
D2's with 9/7 springs pretensioned as much as possible (probably equivolent to 10/8)
Whiteline sways on full stiff all around
Poly bushings everywhere
Pillowball adjustable TC and RUCAs
Camber: -4f/ -3r

Tires:
Hoosier AS304 275/40/R17 up front
Hoosier AS303 315/35/R17 in rear

Eventually going fiberglass front fenders, cf hood, and all SM legal weight reductions


Pros:
Awesome autox setup. Very little to complain about besides the diff and some tire clearance issues still not being resolved yet.

Cons:
Expensive
Horrible for daily driving

[HaLo]

I was planning to add an S15 diff to my car... Get an S14 SR20DET engine... and see what that does.
I also have spare springs (pair of 9) to do a 9/7 setup for my D2 coilovers too... I was thinking about a carbon hood (with or without vent) and maybe fenders.

But is weight reduction such an issue at our power level?

[Rennen]

But is weight reduction such an issue at our power level?

Take a look at the prep level of the previously mentioned M3s and that will be rhetorical. :)


The reason we have not seen a 240SX do well at nationals is that it was never the car to have. No Nationals level driver has ever chosen to campaign it. While alot of people talk about its potential, no one has stepped up on the Nationals stage with the right combination of balls and budget to get into the trophies.


That said, I think a 240SX could trophy or even win SM at nationals in the next few years. Any turbo application can produce the power as the class leading M3s in SM, and as AceInHole has shown, we can fit enough rubber under the car. The rest is gearing and fine tuning the suspension.


Personally, I autocross alot, but I don't consider myself to be autoXing seriously. My long term plan is to be competitive in DSP in the next couple years. I will run a carb'd KA24E in my fastback for simplicity and weight, lightweight battery, header->high flow cat-> straight pipe, coilovers 9/7 most likely, whiteline sways, poly bushings everywhere, widest Hoosiers I can fit under bolt on flares on light wheels. That's pretty vague, but after I graduate, I should be able to afford it, then spend the rest of the time fine tuning my setup, and hopefully you will see my name on the trophies list at Topeka in 2006 or 7

-Matt

[HaLo]

Gearing is another nice issue to raise. Final drive, would you change it or not? If you do, to what?

[hurleyboi514]

ok, this is the 3rd time im replying to this... its always messing up, uber gay. anyways...

ive run both SM and DSP in my S13 fastback. i started in SM b/c i had adjustable rear arms and most of the interior was gutted. i ran SM with Azenis and i did ok, mid pack, but it was also my first year of autoxing. this winter, i returned the car to a DSP prep. sold the illegal parts, then set the car up to maximize the DSP rules. so, this year, ive run DSP all year. i also made the jump to race rubber (victo racers, 225/245). ive won about half of the autox's ive run. the guys im racing against have been doing this for much longer, have better cars (ie more prepared), and usually run Hoosiers (doh!), so im pretty happy with my results. the car does pretty well, it could use wider wheels/tires with some fender flares to maximize grip, but other than that, it does pretty well. anyways, here is my set up:

engine:
battery located intake with Apexi filter
OBX header
test pipe
65mm HKS hiper (would like something lighter maybe)
ASP crank pulley
fidanza flywheel
exedy sport clutch (gay, i loved my dual friction so much more)
removed AC, clutch fan, and all emmissions
SAFC II

suspension:
D2 coilovers (7/5) i need to change springs, stiffer!!
Whiteline sway bars
Whiteline bushings (all of them)
generic strut tower bars
helical LSD (s15)

other:
Momo wheel Mod 7
Sparco speed seat

i like this set up, and their isnt much more to do to it. i can still rebuild the motor (shave head, bore out a little, port match head, port intake manifold), and add a roll cage. other than that, its about maxed out. it does well, ive just gotta get it all dialed in. if i were 100% hard core into autox, what it'd do next is put fender flares on it and try and put a 275 front and rear on the car!! :)

[HaLo]

Interesting. Where are you in your standings? I finished 5th, some 0.2 % off 3rd place, 1% off first place.

[hurleyboi514]

1st in one region (south carolina region), i think 2nd or 3rd in another (central carolinas region).

hey, HaLo, think you could locate an OEM rear valance maybe? id like one, but im having a hard time finding one. i can run aero parts as long as they are OEM. the rear wing is open (minus functional wings), and you can add a lip to the front bumper. i used to have the PDM lip but it got destroyed. im gonna get another, but id like a urathane rear valence. thanks...

[HaLo]

i'll see what i can source... but they are very hard to source... pdm sells the same, in fiberglass.

[hurleyboi514]

alright, sounds good... thanks! only reason i want oem is so i dont get protested... yah i know thats gay, but damn, i got bumped out of the lead in CCR b/c i didnt have my back seat cushion in. yah, the bottom piece, not the whole thing, just the bottom foam piece. shiesh!!

[AceInHole]

after next may i should start working full time = go to SCCA Nats. Should be equipped to hang with the best... just need to increase my level of focus while autocrossing. Even at Canadian Nationals, I don't think I had the same focus as when I felt I was driving my best.

[HaLo]

PJ, if you go to Nationals, I might go with you... see what we can do there.. :D

[Bbandit]

I havent seen any perfect SM 240sx (At least here around my area).
I dont know much about S14 but all I know is that S14 handles a bit better than S13 in a same given mods. I drove my buddy's S14 (Similar suspension mods with mine) in an autocross practice once.. and boy.. I can surely say that S14s are more predictable and stable.

I currently run in SSM (Street Tire Unlimited) in my club and STU in any other autocrosses.
I've used FM901s before and they sucked. Now I'm using avs es100s. es100s are pretty good for the price.. but If you're doing 8 autocross runs (have someone co-drive with you).. you're pretty much running on butter for the last 4 runs. Now I'm thinking about going with the new falkens thats coming out soon.
I don't want to jump into SM and run Rs yet cuz I don't think I'm ready yet. The car needs a lot of work and so does my driving.

Here's my setup
Tein HE (I dont really like how this coilover perform in autocrosses.. it feels like the damper and the spring doesnt co-operate that good)
2 way helical LSD (4.368 final gear): I like the gearing but after the turbo... I'm not really a fan of it. Rear tires spin too easy at the exit. Doesnt matter if you late apex or early apex.. whatever you do... it will break loose the first second or two you put your foot on the gas pedal.

Stock sways: I think I need to upgrade... but I dont want to upgrade anything until I can figure out why I cant push the car to its limit yet.

Front camber is set to -2.0: I'm going to try and set it down to -1.5 and see what happens... at -2.0 the turn ins are good

Rear Camber is prolly around -3.0 ~ -3.5 (I dont have Adjustable rear links): I should invest some money in this area cuz I'm 90% sure that this is the one thing thats holding me back.

I finished 5th (out of 25) in my class (SSM) in the first autoX of this semester, but I was pretty dissappointed. I got beat by a z06, sti, evo8, and B4C camaro. I know I can cut off 1-2 more second out of my time but the car wont let me.

One more thing I noticed with S13s is that the front end doesnt feel solid enough. It feels like its flexing during turn ins and back to back fast/narrow slaloms.

I dont know.. my car feels twitchy right now.. I just think that S13s are a tricky car to tune (suspension/handling wise).. Thats why we havent seen any perfect SM 240s (S13)

[Cr0usEEE]

ok people...im trying to get this exact problem theory settled with my personal project that is going into its 1st year since start...

current goals and parts...
vg30et engine with upgraded rods and pistons, and t5 tranny
5 lug all around with 300zx rear uprights, brakes, and mc
currently have a set of 300zx tt rear wheels for r compounds.
tec II tomfoolery

working on now...
suspension...making my own adjustable control arms out of chromoly...with the ability to change roll center of the car.
planning on going with koni shocks all around with ground control springs, works great on its cars, and my roommates rx-7
lsd...quaifle would be great, sticking with either the stock 4.10s or maybe 3.73's.

things i would like to try...
wheels in 15x10 or 15x12 inch sizes that clear brakes...its possible i know it, or just wider 16's. 17's imo are not with the higher cg and weight. 315's all around would be nice.

after i finish doing all this to my car, i will probably rip it all out and find a 89 240sx base coupe and start with that. fastback owners are already at a disadvantage...but i like the fact that i can fit my race tires in the back of my car at the event.

benefits of coupe...

lighter with no heavy rear hatch or window. rear truck lid can be replaced with carbon fiber, along with front fenders and hood.
no sunroof would be helpful too.

i will build a nationally competitive 240sx...to take on the current ringer 95 m3 coupe lightweight....damn that run of 1200 production lightweight m3's...(alum doors, trunk, hood, and extra rear bracing brought over from the m3 convertable.)

[thx247]

Is that legal to change the roll center on SM cars?

[240sxconversion]

the M3 and Civic don't really worry me...I'm waiting for somebody to find a decent RWD chassis that weights the 2400lb minimum weight, cram a 3L f/i engine in it, and develop the suspension. The first thing that pops to mind is a Supra TT-powered AE86...don't know if that swap is possible, but you get my point.
I am not into auto x yet, but that is because i am in Pheonix arizona and my car is in Pennsylvania. Anyway, is it legal to drop a rb30 into the 240sx. Even if i went with a N/A setup, which i am not planing on, but it makes low end HP and torque. here is my possible rb30 setup.
http://members.cardomain.com/240sxdrifter04
I could just get rb26 pistons, and then the compresion would be around 10:1 i believe or is that the NA rb30 pistons, ok, i am not sure for the moment.

[Rennen]

Is that legal to change the roll center on SM cars?


I am not sure, the only suspension restriction is that they attach the original mounting points....

I don't know if that means the LCA can be modified or not since it would be moving a suspension mounting point, but not a mounting point on the chassis? :confused:

-Matt

[Cr0usEEE]

only mounting points that matter from my interpretation of the rules are the ones that attach to the frame/body and not to the actual arms...if that was the case then adjustable upper and lower control arms would be illegal since you can move the lower shock mounting point by about a 1/4" either way by adjusting the inner heim joints.

also subframe spacers are techincally illegal in sm, but delrin replacement bushings are not.

[LanceS13]

I wasn't aware that the M3's had gotten that light...forgot about the Lightweights. No wonder they're so fast.

You can change roll center at the hub end of the arm, but not at the chassis attachment point.

And a c/f trunk and a c/f hatch are no different...both are illegal in SM. Doors, roof, trunk/hatch, and rear quarter panels must remain stock. The only exception would be the rule that allows fender flares added to the quarter panels and spoilers added to the trunk/hatch.

[AceInHole]

things i would like to try...
wheels in 15x10 or 15x12 inch sizes that clear brakes...its possible i know it, or just wider 16's. 17's imo are not with the higher cg and weight. 315's all around would be nice.
where are you getting 315 wide 15's or 16's??

[Cr0usEEE]

I wasn't aware that the M3's had gotten that light...forgot about the Lightweights. No wonder they're so fast.

You can change roll center at the hub end of the arm, but not at the chassis attachment point.

And a c/f trunk and a c/f hatch are no different...both are illegal in SM. Doors, roof, trunk/hatch, and rear quarter panels must remain stock. The only exception would be the rule that allows fender flares added to the quarter panels and spoilers added to the trunk/hatch.


i could have sworn i read in fasttrack that a new rule was proposed to allow replacement trunks and such....

btw ace...i said 315's would be nice not that they exist...to bad you cant run pure race tires in street mod, oh well.

[98sr20ve]

This is not that hard. First thing you have to do is realize that you have to spend money to win. D2's will not cut it. Not at the national level on the bumpy courses that they run. Do you really think the M3 guys are buying cheap coilovers? This stuff matters. Cheapest thing that might work would be the Advance design stuff GC makes. It would be a start. Then, fenders flares, Wide tires, Great LSD, Turbo KA or SR, 350whp with very little lag is the starting point. All the weight reduction you can do, all the suspension work you can do, all the stiffening that you can do of the chassis. Chassis stiffening is the primary issue to get fixed I think. The suspension can get you there if you do it right, Power is also not going to be a problem with the turbo KA or SR. Honestly the turbo SR with the 2.2 kit would probably be the best from a weight and HP point of view. The problem is that no one has spent the money to make the car capable of winning. It's as simple as that. After that you need a great driver and someone who knows how to set it up.

[Cr0usEEE]

if you really want to be serious, you dont go forced induction in sm, you go na. vq35 in a 240 would be light and could make around 350 horse if it was worked correctly

from what i was told, nationals isnt that bumpy, sure its big ass concrete slab but its gotta be somewhat level.

[AceInHole]

$$$ isn't the only thing that's gonna matter. Even revalved Konis have been working great for a lot of people I know that are regularly competative on the national level.

I wouldn't mind a custom 3-way ohlins setup.... though.

[98sr20ve]

$$$ isn't the only thing that's gonna matter. Even revalved Konis have been working great for a lot of people I know that are regularly competative on the national level.

I wouldn't mind a custom 3-way ohlins setup.... though.

Koni's are good.

[thx247]

where are you getting 315 wide 15's or 16's??

Diamond makes wheels in that size for a reasonable cost but I don't know if they will fit.

[hurleyboi514]

you may be able to get a wide 16 wheel, but still, the problem is there are no wide 16" tires...

[98sr20ve]

You need Hoosiers or the new Kuhmo to compete. They make a 275/45/16 for the hoosier and a 265/45/16 for the Kuhmo. If you want wider you need to go to 17's.

[thx247]

SM can't run slicks? I should find out for myself but Im lazy and @ work! Shhhhhh

There are lots of wide small slicks, but not DOT approved. Once again, I forget sm rules.

[98sr20ve]

SM can't run slicks? I should find out for myself but Im lazy and @ work! Shhhhhh

There are lots of wide small slicks, but not DOT approved. Once again, I forget sm rules.

The tires I listed are DOT tires. They are the ideal SM tire. They are the standard tires of the class.

[thx247]

Ok so no slicks then?

[LanceS13]

no slicks...only DOT tires

[HaLo]

Hoosiers and Kumho V710 can be almost considered as slicks..

[98sr20ve]

Hoosiers and Kumho V710 can be almost considered as slicks..

Yes, they are that sticky. BUT If you are not running them or a tire like them you will lose at the national level. Simple as that.

[HaLo]

Actually, no tires are alike the V710 or the Hoosier A3S04s...
You can try running RA1, A032R. V700, but you'll never be close enough.

[98sr20ve]

Actually, no tires are alike the V710 or the Hoosier A3S04s...
You can try running RA1, A032R. V700, but you'll never be close enough.

I agree. I was leaving room for some of the euro spec tires that I know nothing about but that tire rack recently started carrying. Avon springs to mind.

[AceInHole]

don't forget that size does matter
http://www.engr.uconn.edu/~corrales/carsIM/wheeltest/IMG_8458.JPG

[HaLo]

Size does matter to a certain extent.

If your suspension cannot fully use the grip of your tires, then size does not matter. ;)

[98sr20ve]

don't forget that size does matter

So what size is that and what size did you run before. Were they similiar tires as well. How do you like that HUGE tire on the car.

[AceInHole]

that is 315/35/R17. up front is 275/40/R17. All Hoosier. Before was 245/45/R16 Victoracer. Lots of grip now. Still getting used to it. Tweaking suspension to utilize it.

[HaLo]

To fully user your tires, I believe custom Ohlins with independant fluid reservoirs might be a nice choice.

I should send the D2s to have them dynoed (at Koni), see how well they do. On thing is for sure, my next setup will be re-valved Konis with custom ground control springs. :D

[AceInHole]

To fully user your bank acccount + credit limit, I believe custom Ohlins with independant fluid reservoirs might be a nice choice.

I'm probably gonna cheap out and get revalved Zeal Super Functions instead.

[HaLo]

How do the Zeal fare out compared to other coilovers?

[hurleyboi514]

i wonder if the d2 bodies could house a koni??? :)

[HaLo]

that's something to explore.... :D