Suspension set ups for road racing

uaoSTI · 10-09-2009, 05:12 PM

I have been running my 05 STI now at the Miller track outside of SLC for 2 summers and I would really love to learn how to improve the handling of my car. So I am looking for some feedback, set up tricks or other input to help me come up with a great set up for my car next spring.

Current set up:

H&R street perf coilovers

Stock swaybar front

Cobb swaybar rear

stock wheels with 225 or 235 R compound tires

front and rear strut bars (tien)

rear seats removed

spare tire removed (at track)

My thoughts on what I need:

- Camber Plates

-wider rims/tires (17x9 rims,245 tires)

Issues: TONS of understeer!

Please share your set ups!

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generalee69 · 10-09-2009, 05:41 PM

First I've got a bunch of questions for you
-What spring rates are you running on your coilovers?
-Which R comps are you running?
-Stock body work/aero?
-How are your tire pressures when you come off the track?

I personally like the car neutral to slightly loose. In order to get there with my car I have the compression rebound settings at full hard in the rear, and 3/4 hard in the front. Camber is at about -3* front, -1.5 (or -2.0) rear.
I'm running 10k front, 8k rear springs.

And then with the big wing on the back that is jack way up, I need the rear to be pretty firm compared to the front in order to get the car to rotate. Not saying my way is the best (definitely not the only), but so far it has been the only way I can get the car feel really good.

Then once it was all feeling pretty good... I broke the motor... again

Good luck.

Robbie_B · 10-09-2009, 05:41 PM

Quote:

Originally Posted by uaoSTI

I have been running my 05 STI now at the Miller track outside of SLC for 2 summers and I would really love to learn how to improve the handling of my car. So I am looking for some feedback, set up tricks or other input to help me come up with a great set up for my car next spring.

Current set up:

H&R street perf coilovers

Stock swaybar front

Cobb swaybar rear

stock wheels with 225 or 235 R compound tires

front and rear strut bars (tien)

rear seats removed

spare tire removed (at track)

My thoughts on what I need:

- Camber Plates

-wider rims/tires (17x9 rims,245 tires)

Issues: TONS of understeer!

Please share your set ups!

Camber plates are a must, 17x9 and 245 is a waste. Keep unsprung weight down and go 17x8. Performance alignment should be a must. A larger front bar and ALK would help too.

That said, where are you driving? HPDE? NASA? SCCA? Class? For fun?

uaoSTI · 10-09-2009, 05:45 PM

Quote:

Originally Posted by Robbie_B

Camber plates are a must, 17x9 and 245 is a waste. Keep unsprung weight down and go 17x8. Performance alignment should be a must. A larger front bar and ALK would help too.

That said, where are you driving? HPDE? NASA? SCCA? Class? For fun?

What is ALK?

I only drive for fun (local lap battles - AWD class with race tires)

Currently running R1's for tires on 17x8 stock rims

why do i need a larger front bar? i would like to get rid of understeer - would a larger front PROMOTE more understeer? (that is my impression anyways)

should also note: cobb rear sway bar is set to loosest (longer) set up of 3 options (shorter,stock,longer)

uaoSTI · 10-09-2009, 05:50 PM

-What spring rates are you running on your coilovers? NOT sure, will have to email H&R to figure this out

-Which R comps are you running? R1s currently

-Stock body work/aero? Front splitter, stock everything else

-How are your tire pressures when you come off the track?
i try to keep tires at about 40 psi all around (with R compounds, closer to 50 with street tires on track)

generalee69 · 10-09-2009, 05:54 PM

Quote:

Originally Posted by uaoSTI

-What spring rates are you running on your coilovers? NOT sure, will have to email H&R to figure this out

-Which R comps are you running? R1s currently

-Stock body work/aero? Front splitter, stock everything else

-How are your tire pressures when you come off the track?
i try to keep tires at about 40 psi all around (with R compounds, closer to 50 with street tires on track)

Are you coming off the track and finding a 2 or 3 degree difference between the front and the rear? Or are they pretty balanced?

How does the tread look on the outer edge of the tire? Pretty chewed up?

What pressures do you go onto the track with?

Before you go buying anything, you've got enough stuff already that you can play with to do a couple of things that will make you faster and make the car feel better.

ALK - is an anti-lift kit.. you can read about them in the FAQ's.

uaoSTI · 10-09-2009, 06:13 PM

I am going out next saturday (17th) and will pay attention to the temp differences.

The outside of the tires definitely get shredded but the sidewall holds up ok.

found the FAQ, thanks

growling_boxer · 10-10-2009, 02:15 AM

i believe the H&R coilover rates are around 460 front and 300 rear, which ended up being the reason i did not buy them. they were too front-biased compared to other setups i saw that were actually designed specifically for the STi. i wanted more front grip, and ended up with the RCE T0s, which are 400 front 340 rear. the TiC AST suspension was around 400 front and 300 rear.

generalee69 · 10-10-2009, 03:12 PM

Quote:

Originally Posted by uaoSTI

I am going out next saturday (17th) and will pay attention to the temp differences.

The outside of the tires definitely get shredded but the sidewall holds up ok.

found the FAQ, thanks

Perfect oppurtunity to play with things then. I'd start by running a couple more PSI in the rear tires than the front BEFORE you go on the track.

While you are on track be very gentle with the throttle, if you are off the line a little don't just hammer into the throttle to pull you out of the corner. That will for sure heat up the fronts, and make it push like crazy.

If you don't see an improvement, then soften up the front compression/rebound (or stiffen the rear). When you do this, make a pretty drastic change at first (go from full firm to half firm on the fronts). The car should start to handle like it is rear wheel drive and like the a$$ wants to come around on you.

If you can get to an alignment shop before your track day, try to get as much front camber as you can.

mav1c · 10-10-2009, 03:21 PM

You haven't mentioned your alignment settings, but I'm guessing it's fairly close to stock if you don't have front camber plates.

Surb00 · 10-10-2009, 03:34 PM

Quote:

- would a larger front PROMOTE more understeer? (that is my impression anyways)

Not on your STi. A larger front bar will help the front tires maintain a larger contact patch. It worked on my car and was confirmed with several drivers swapping between stock and a whiteline 24mm(relatively easy to do at the track). Try it they're relatively inexpensive.

jamal · 10-10-2009, 06:00 PM

rear springs at least as stiff as the fronts, more front camber, ALK, bigger swaybars front and rear.

with tires that sticky you should have a bit more roll stiffness than you do now.

uaoSTI · 10-11-2009, 08:48 PM

Alignement is in -1 range but nothing awesome due to stock settings. I will definitely pay more attention to PSI and look into ALK and front swaybar next spring. Car will be in winter mode soon but I wanted to use this thread to plan my spending spree for next tax season!

elirentz · 10-11-2009, 09:04 PM

Yeah it seems counter intuitive but a bigger front bar can actually help get rid of understeer on subies. With some extra front camber it can make a huge difference. I would look at a whiteline front bar and I really love my PDE camber plates as they can reliably be adjusted at the track to give you a street and track setting that stays same with the adjustments.

FromageTheDog · 10-12-2009, 01:27 PM

I have a WRX and not an STi, but since I have STi springs, I figure this discussion will benefit me too. I have an extremely mild suspension setup (sways/struts/springs, camber -1.5* front, -0.5* rear) that I'm starting to outgrow. I'm actually quite happy with the steady-state behavior: long sweepers, gentle side-side transitions, and so on. On the other hand, a ride-along in a coach's "stock as stock can be" Mazdaspeed3 also really illustrated to me just how abysmal my car was in terms of power-on understeer. What's the typical approach, here? Is the ALK the magic bullet?

This is also my daily driver, so I'm trying to avoid going the camber plate route -- but if the only answer is "a lot more camber," then I may just have to bite the bullet...

elirentz · 10-12-2009, 01:40 PM

Quote:

Originally Posted by FromageTheDog

This is also my daily driver, so I'm trying to avoid going the camber plate route -- but if the only answer is "a lot more camber," then I may just have to bite the bullet...

Curious as to why you want to avoid camber plates on a daily driver?

EROCK · 10-12-2009, 01:49 PM

Quote:

Originally Posted by FromageTheDog

This is also my daily driver, so I'm trying to avoid going the camber plate route -- but if the only answer is "a lot more camber," then I may just have to bite the bullet...

I have camber plates (whiteline) on my STi with stock struts and the NVH isn't bad at all. As others have said the adjustability from street to track settings is fairly quick and is a great option IMO even sticking with the stock strut setup.

575rider · 10-12-2009, 03:34 PM

OP: Back to the ALK (anti lift kit), I found it to make a huge diff on the track. Brake dive is not completely gone but the back end doesn't get near as light and "floatie" feeling as it used to. And, corner exit is far superior since the inside front doesn't get light and spin anything like it did. I'd recommend a larger fsb and endlinks all the way around. Adjustable bars preferred. Is your rsb adjustable? I've been able to get my car very close to neutral with a hint of oversteer using the following:
22 mm swaybars all the way around, with endlinks. 3 way adj rsb set at stiffest setting, 2 way adj fsb set at stiffest setting.
H-brace, ALK, upper strut tie bars fr and rr.
I have Eibach prokit springs and Tokico d-spec struts. I set the rear up with more compression and rebound than the front.
I'm getting camber plates soon. Before I bought the D-specs I had my camber set at -1.2 degrees front and rear, I can't get as much neg camber with the tokico struts unfortunately, that's why I'm getting the plates up front.
I was running tire pressure at 40psi all the way around, still playing with it a bit though.
Whiteling steering rack bushings helped make the car react and feel much better too.
My wagon and your STI are 2 diff animals but this info might help you out a bit.

growling_boxer · 10-13-2009, 12:34 PM

Quote:

Originally Posted by 575rider

OP: Back to the ALK (anti lift kit), I found it to make a huge diff on the track. Brake dive is not completely gone but the back end doesn't get near as light and "floatie" feeling as it used to. And, corner exit is far superior since the inside front doesn't get light and spin anything like it did.

I am so confused about what the ALK actually does. It sounds like it should do what you suggest it does from the name, and I have heard that from others as well. However, I have also read this, which says the opposite:

Quote:

Originally Posted by TurnInConcepts.com

Here's what it does:

Stiffer bushing gives a more solid mounting point for the suspension which does a few things. Most important of these is better toe control at speed/braking and crisper turn-in. Any stiffer aftermarket bushing (including the STI group N part) does this.
Extra caster which gives a stronger on-center feel to the steering as well as more "dynamic camber" during cornering.
Removes the anti-lift and anti-dive characteristics of the stock suspension. What this means is that it effectively softens your front suspension's movement during fore/aft weight transfer which allows the wheel to follow the road a little better during acceleration/braking in a corner.

06ICYWRX · 10-13-2009, 12:46 PM

Give me a call If you like Some setup notes. 215 837 8117

Klevis.

FromageTheDog · 10-13-2009, 02:17 PM

Quote:

Originally Posted by growling_boxer

I am so confused about what the ALK actually does. It sounds like it should do what you suggest it does from the name, and I have heard that from others as well. However, I have also read this, which says the opposite:

It should come as no surprise that TiC has it right. Whiteline has a nice, detailed write-up here:

http://www.whiteline.com.au/articles...WL%20ALK_b.pdf

growling_boxer · 10-13-2009, 02:41 PM

I assumed TiC got the theory right, but softening up the front didn't sound like something I wanted to do, especially with the higher rear end spring rate bias I have with the RCE T0s (400/340). However, this paper has me thinking maybe I do, since it is definitely not the same as softening the front springs.

sil0nt · 10-19-2009, 04:13 PM

I like the RCE T2 500/400 setup. I've run it for a couple years now and have no problems. A well designed coilover package will improve handling more than a few bushings here and there.

UFOpilot · 10-19-2009, 05:23 PM

IMO camber should be used to tune, tire pressure should be used to fine tune once you get there. If you are running stock camber settings, all that fine tuning pressure will get you is a compromise of masking the issue.

Just one more opinion in a sea of too many.

904scooby · 10-19-2009, 05:47 PM

Camber plates will be the easiest and most cost efficient way to get the camber you need, I'm still in the testing phases of my own race suspension set-up and am not happy with it yet, I like uber-stiff springs for racing with my cusco coilover set-up. My front - camber is at -2, I have been told numerous times its not enough, but I'm playing with it to get a better feel for my car instead of just taking it all the way to -3, back is at -.5.

10-09-2009, 05:12 PM	#1
uaoSTI Scooby Newbie Member#: 175957 Join Date: Mar 2008 Chapter/Region: RMIC Location: SLC, UT Vehicle: 2005 Subaru STI Silver	Suspension set ups for road racing I have been running my 05 STI now at the Miller track outside of SLC for 2 summers and I would really love to learn how to improve the handling of my car. So I am looking for some feedback, set up tricks or other input to help me come up with a great set up for my car next spring. Current set up: H&R street perf coilovers Stock swaybar front Cobb swaybar rear stock wheels with 225 or 235 R compound tires front and rear strut bars (tien) rear seats removed spare tire removed (at track) My thoughts on what I need: - Camber Plates -wider rims/tires (17x9 rims,245 tires) Issues: TONS of understeer! Please share your set ups! * Registered users of the site do not see these ads.

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10-09-2009, 05:41 PM	#2
generalee69 Scooby Specialist Member#: 106470 Join Date: Feb 2006 Chapter/Region: NWIC Location: Kent WA Vehicle: 2004 STI ICSCC #491 www.ClintonRacing.com	First I've got a bunch of questions for you -What spring rates are you running on your coilovers? -Which R comps are you running? -Stock body work/aero? -How are your tire pressures when you come off the track? I personally like the car neutral to slightly loose. In order to get there with my car I have the compression rebound settings at full hard in the rear, and 3/4 hard in the front. Camber is at about -3* front, -1.5 (or -2.0) rear. I'm running 10k front, 8k rear springs. And then with the big wing on the back that is jack way up, I need the rear to be pretty firm compared to the front in order to get the car to rotate. Not saying my way is the best (definitely not the only), but so far it has been the only way I can get the car feel really good. Then once it was all feeling pretty good... I broke the motor... again Good luck.

10-09-2009, 05:50 PM	#5
uaoSTI Scooby Newbie Member#: 175957 Join Date: Mar 2008 Chapter/Region: RMIC Location: SLC, UT Vehicle: 2005 Subaru STI Silver	-What spring rates are you running on your coilovers? NOT sure, will have to email H&R to figure this out -Which R comps are you running? R1s currently -Stock body work/aero? Front splitter, stock everything else -How are your tire pressures when you come off the track? i try to keep tires at about 40 psi all around (with R compounds, closer to 50 with street tires on track)

10-09-2009, 06:13 PM	#7
uaoSTI Scooby Newbie Member#: 175957 Join Date: Mar 2008 Chapter/Region: RMIC Location: SLC, UT Vehicle: 2005 Subaru STI Silver	I am going out next saturday (17th) and will pay attention to the temp differences. The outside of the tires definitely get shredded but the sidewall holds up ok. found the FAQ, thanks

10-10-2009, 02:15 AM	#8
growling_boxer Scooby Specialist Member#: 165744 Join Date: Dec 2007 Chapter/Region: Tri-State Location: Eastern PA Vehicle: 2000 LGT 2005 STi	i believe the H&R coilover rates are around 460 front and 300 rear, which ended up being the reason i did not buy them. they were too front-biased compared to other setups i saw that were actually designed specifically for the STi. i wanted more front grip, and ended up with the RCE T0s, which are 400 front 340 rear. the TiC AST suspension was around 400 front and 300 rear.

10-10-2009, 03:21 PM	#10
mav1c Hoodbridge! Moderator Member#: 560 Join Date: Nov 1999 Chapter/Region: MAIC Location: Woodbridge, VA Vehicle: 2006 STi, '05 Mazda3 Crystal Gray, Titanium	You haven't mentioned your alignment settings, but I'm guessing it's fairly close to stock if you don't have front camber plates.

10-10-2009, 06:00 PM	#12
jamal Scooby Specialist Member#: 71875 Join Date: Oct 2004 Location: Compton Vehicle: 98 2.5GT my wheels fit	rear springs at least as stiff as the fronts, more front camber, ALK, bigger swaybars front and rear. with tires that sticky you should have a bit more roll stiffness than you do now.

10-11-2009, 08:48 PM	#13
uaoSTI Scooby Newbie Member#: 175957 Join Date: Mar 2008 Chapter/Region: RMIC Location: SLC, UT Vehicle: 2005 Subaru STI Silver	Alignement is in -1 range but nothing awesome due to stock settings. I will definitely pay more attention to PSI and look into ALK and front swaybar next spring. Car will be in winter mode soon but I wanted to use this thread to plan my spending spree for next tax season!

10-11-2009, 09:04 PM	#14
elirentz Scooby Specialist Member#: 70082 Join Date: Sep 2004 Chapter/Region: South East Location: charleston, sc Vehicle: 2005 sti wrb 88 944 beater	Yeah it seems counter intuitive but a bigger front bar can actually help get rid of understeer on subies. With some extra front camber it can make a huge difference. I would look at a whiteline front bar and I really love my PDE camber plates as they can reliably be adjusted at the track to give you a street and track setting that stays same with the adjustments.

10-12-2009, 01:27 PM	#15
FromageTheDog Scooby Specialist Member#: 81095 Join Date: Feb 2005 Chapter/Region: BAIC Location: Left seat. Vehicle: 2005 WRX: Platinum Silver VeryVeryDirty	I have a WRX and not an STi, but since I have STi springs, I figure this discussion will benefit me too. I have an extremely mild suspension setup (sways/struts/springs, camber -1.5* front, -0.5* rear) that I'm starting to outgrow. I'm actually quite happy with the steady-state behavior: long sweepers, gentle side-side transitions, and so on. On the other hand, a ride-along in a coach's "stock as stock can be" Mazdaspeed3 also really illustrated to me just how abysmal my car was in terms of power-on understeer. What's the typical approach, here? Is the ALK the magic bullet? This is also my daily driver, so I'm trying to avoid going the camber plate route -- but if the only answer is "a lot more camber," then I may just have to bite the bullet...

10-12-2009, 03:34 PM	#18
575rider Scooby Specialist Member#: 112024 Join Date: Apr 2006 Chapter/Region: NWIC Location: Portland Vehicle: 03 vf34,AVO,STI, Cusco wagon/05 LGT too	OP: Back to the ALK (anti lift kit), I found it to make a huge diff on the track. Brake dive is not completely gone but the back end doesn't get near as light and "floatie" feeling as it used to. And, corner exit is far superior since the inside front doesn't get light and spin anything like it did. I'd recommend a larger fsb and endlinks all the way around. Adjustable bars preferred. Is your rsb adjustable? I've been able to get my car very close to neutral with a hint of oversteer using the following: 22 mm swaybars all the way around, with endlinks. 3 way adj rsb set at stiffest setting, 2 way adj fsb set at stiffest setting. H-brace, ALK, upper strut tie bars fr and rr. I have Eibach prokit springs and Tokico d-spec struts. I set the rear up with more compression and rebound than the front. I'm getting camber plates soon. Before I bought the D-specs I had my camber set at -1.2 degrees front and rear, I can't get as much neg camber with the tokico struts unfortunately, that's why I'm getting the plates up front. I was running tire pressure at 40psi all the way around, still playing with it a bit though. Whiteling steering rack bushings helped make the car react and feel much better too. My wagon and your STI are 2 diff animals but this info might help you out a bit.

10-13-2009, 12:46 PM	#20
06ICYWRX Scooby Newbie Member#: 131358 Join Date: Nov 2006 Chapter/Region: Tri-State Location: philly Vehicle: 2006 WRX Blue ECUTEK, JRZ	Give me a call If you like Some setup notes. 215 837 8117 Klevis.

10-13-2009, 02:41 PM	#22
growling_boxer Scooby Specialist Member#: 165744 Join Date: Dec 2007 Chapter/Region: Tri-State Location: Eastern PA Vehicle: 2000 LGT 2005 STi	I assumed TiC got the theory right, but softening up the front didn't sound like something I wanted to do, especially with the higher rear end spring rate bias I have with the RCE T0s (400/340). However, this paper has me thinking maybe I do, since it is definitely not the same as softening the front springs.

10-19-2009, 04:13 PM	#23
sil0nt Scooby Specialist Member#: 30584 Join Date: Nov 2002 Chapter/Region: MWSOC Location: Chicago Vehicle: 05 STi Black 07 S4 Avant Black	I like the RCE T2 500/400 setup. I've run it for a couple years now and have no problems. A well designed coilover package will improve handling more than a few bushings here and there.

10-19-2009, 05:23 PM	#24
UFOpilot NASIOC Supporter Member#: 189525 Join Date: Sep 2008 Chapter/Region: NWIC Location: Portland Oregon Vehicle: 2007 WRX Wagon Invisible Plain	IMO camber should be used to tune, tire pressure should be used to fine tune once you get there. If you are running stock camber settings, all that fine tuning pressure will get you is a compromise of masking the issue. Just one more opinion in a sea of too many.

10-19-2009, 05:47 PM	#25
904scooby Scooby Specialist Member#: 151518 Join Date: Jun 2007 Chapter/Region: South East Location: J-ville Vehicle: 2005 18g'd WRX CGM	Camber plates will be the easiest and most cost efficient way to get the camber you need, I'm still in the testing phases of my own race suspension set-up and am not happy with it yet, I like uber-stiff springs for racing with my cusco coilover set-up. My front - camber is at -2, I have been told numerous times its not enough, but I'm playing with it to get a better feel for my car instead of just taking it all the way to -3, back is at -.5.