Advise needed: track junkies w. square street tires set up

[wwjd15]

Previous set up:
Hankook R-S3 265/35 18 and 285/35 18
Track: Buttonwillow 13W
Everything was predictable, very easy to drive, but I experienced bouncy rear end issue at corner riverside at Buttonwillow.

Set up I have:
Hankook R-S3 285/35 18 all around
Track:
1 Big Willow
No problem at this track, just a bit oversteering during some tight corner exiting, but it's predictable.
2 Buttonwillow 13 CCW
Overall driving experience is better, less understeering. But it's harder to drive due to sensitive front end. Also, I experienced unstable front end after corner Riverside and during the entire corner Track Stop.

I'm not sure if my driving line was wrong or the car doesn't like square set up? I have asked some guys with square but they were on R-compounds so that's not the case.
Any input is welcome. Thanks!

[Gearhead999s]

My car on 275/35 18 NT05's on 18 x 10's is quite stable and easy to drive on with very mild understeer on turn in & mid corner with power on oversteer on exit.I am very happy with the overall balance with stock competion suspension.Here is a short video of it in action.

http://www.m3post.com/forums/showpos...6&postcount=40

[wwjd15]

^^ Thanks! have you driven through high speed but tight corners? How's that feel?

[Gearhead999s]

Originally Posted by wwjd15

^^ Thanks! have you driven through high speed but tight corners? How's that feel?

Yep at Watkins Glen & Mosport GP and it is just on the light understeer side of neutral which is great on both of those tracks for confidence and being able to stay on the throttle.

[wwjd15]

Originally Posted by Gearhead999s

Yep at Watkins Glen & Mosport GP and it is just on the light understeer side of neutral which is great on both of those tracks for confidence and being able to stay on the throttle.

Hmm, then it might be suspension or my driving. I'll try that out next month.
I don't have understeer problem other than some very low speed tight corners.

[aus]

Some have said this car is more prone to oversteer than the E46 M3, which had a lot of understeer, so a staggard set-up was more appropriate.

[Malek@MRF]

Originally Posted by wwjd15

Hmm, then it might be suspension or my driving. I'll try that out next month.
I don't have understeer problem other than some very low speed tight corners.

Ricky, what are your suspension settings. I will be more than happy to help you tune it out.

And you are right, the car does behave a little funny with square setup compared to the stock staggered setup, but it has tons of front end grip this way.

[Malek@MRF]

Originally Posted by aus

Some have said this car is more prone to oversteer than the E46 M3, which had a lot of understeer, so a staggard set-up was more appropriate.

This is correct. The E46 had front end camber issues at the limit too, so many would opt for a very heavy front sway bar with camber plates to minimize the problem.

The E92 is a better balanced car.

[The HACK]

This is akin to asking my surgeon to walk me through an open heart surgery over the phone.

And I'm not a doctor.

My advice to you is, next time you're at Buttonwillow, see if someone familiar with the set-up/chassis will ride with you for a few laps to observe what the car is actually doing, plus what you're doing when the car's dong what it's doing. There are simply too many variables to offer any useful and objective recommendations.

[paradocs98]

I also run a square track setup--275/35-18 Nitto NT01s on 18x10 in Forgelines. This is the setup that Turner recommends. Some have (probably correctly) suggested that it is better to run a square setup with DSC off, because the computer sensors see a staggered tire setup (slightly taller overall rear diameter) as baseline, and the relatively smaller rear diameter of a square setup would cause the rear wheel/tire combo to rotate relatively faster, which could be interpreted by DSC as rear wheel slip. The computer might then be imperceptibly applying braking on individual wheels to compensate, upsetting the balance of the car.

[ShadeD1]

I run 285/30 all the way around. I have 10mm spacers in the rear and 12.5 in the front. I've experimented with various configs and this is the best I've found. I tried 12.5 front and nothing in the rear and the rear end gets really loose, maybe that could be part of your issue?

[trackm4]

Originally Posted by paradocs98

I also run a square track setup--275/35-18 Nitto NT01s on 18x10 in Forgelines. This is the setup that Turner recommends. Some have (probably correctly) suggested that it is better to run a square setup with DSC off, because the computer sensors see a staggered tire setup (slightly taller overall rear diameter) as baseline, and the relatively smaller rear diameter of a square setup would cause the rear wheel/tire combo to rotate relatively faster, which could be interpreted by DSC as rear wheel slip. The computer might then be imperceptibly applying braking on individual wheels to compensate, upsetting the balance of the car.

I run a 275/35 square setup and the DSC note above is pure BS. Never experienced any odd DSC behavior on the track or the street

[ShadeD1]

I've been running a square setup for about 6 events and usually leave MDM on and have had zero issues with the DSC.

Originally Posted by paradocs98

I also run a square track setup--275/35-18 Nitto NT01s on 18x10 in Forgelines. This is the setup that Turner recommends. Some have (probably correctly) suggested that it is better to run a square setup with DSC off, because the computer sensors see a staggered tire setup (slightly taller overall rear diameter) as baseline, and the relatively smaller rear diameter of a square setup would cause the rear wheel/tire combo to rotate relatively faster, which could be interpreted by DSC as rear wheel slip. The computer might then be imperceptibly applying braking on individual wheels to compensate, upsetting the balance of the car.

[paradocs98]

wwjd--Can you post a couple pics of your car? From your avatar it looks nice!

[R A W L S]

OP - I don't have any advise I'm just wondering - do you have any rubbing up front with the 285/35 18 RS-3's? Also, what width are your wheels? Thanks.