Race Tracking Your Supra - Information exchange

[garudathree]

It's a track-dependent tire issue, not camber. I've failed PSS and PS4S in the exact same way on cars with solid track alignments. There's not enough sidewall strength so they roll over and peel the shoulders off.

what's the track alignment that you consider to be "solid"?

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[AHP]

what's the track alignment that you consider to be "solid"?

-2.6° and 0 Toe on the PSS failure and -3.0° and 0 Toe on the PS4S

 

[initialDnut]

I had the same alignment and i run the tires at 38 psi hot.
i am thinking about putting in a lower control arm for next season.

 

[garudathree]

that's not nearly enough camber, fast folks on track run ao52 with -4+ front camber on cars with way more roll stiffness than you guys have. i'm at -4.2 for re71rs and 1100lb front spring, to give you some context.

 

[FLtrackdays]

that's not nearly enough camber, fast folks on track run ao52 with -4+ front camber on cars with way more roll stiffness than you guys have. i'm at -4.2 for re71rs and 1100lb front spring, to give you some context.

I found out the exact same thing. Chewing the outside of my tires too quickly. One alignment shop would do what I asked. Another asked if I wanted it done right. Then proceeded to dial em way up. I’m going to ask if we can go some more (negative). I’m still wearing the outside, just not as quickly or (as harsh) as I did before. Times dropped as well with better stability.

 

[initialDnut]

that's not nearly enough camber, fast folks on track run ao52 with -4+ front camber on cars with way more roll stiffness than you guys have. i'm at -4.2 for re71rs and 1100lb front spring, to give you some context.

Can you get that camber on stock? I thought you need to put camber plates or new control arms to get to to that kind of camber.

 

[razorlab]

Can you get that camber on stock? I thought you need to put camber plates or new control arms to get to to that kind of camber.

No, you need plates and/or LCA. I run both for -4.

 

[AHP]

Purporting you need -4° is silly, IMO. HPDE Winner advice...

In the case of the car that shredded 3 pairs of PS4S with a good track alignment and a check-every-box list of SPL parts -- that was solved by switching to a more track appropriate tire. Zero other changes and never a tire issue again. No amount of negative camber is going to make a PSS or PS4S survive a fast driver. And I've run RE71RS (and many many other 100-200TW) without issue with -3 or less.

Look at the sidewall of the PS4S I posted above and tell me another 1-1.5° would have solved that.

 

[initialDnut]

For anyone in the Mid Atlantic area, or up for a trip like me, i am going to this HPDE event at Summit Point. It is with PCA with a great club based out of PA.

Always fun to show up those squished beetles with the engine in wrong place!

https://www.motorsportreg.com/event...-2024-motorsports-park-pca-riesentoter-096666

 

[garudathree]

Purporting you need -4° is silly, IMO. HPDE Winner advice...

In the case of the car that shredded 3 pairs of PS4S with a good track alignment and a check-every-box list of SPL parts -- that was solved by switching to a more track appropriate tire. Zero other changes and never a tire issue again. No amount of negative camber is going to make a PSS or PS4S survive a fast driver. And I've run RE71RS (and many many other 100-200TW) without issue with -3 or less.

Look at the sidewall of the PS4S I posted above and tell me another 1-1.5° would have solved that.

yup. i've gone through 7 sets of re71rs alone this season. including killing the outside shoulder on a set from testing -3.2 front camber after spring rate change.
all 3 cars here are running -4+ front camber. what results back up your views?

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[AHP]

The key distinction here is full-on race car vs dual purpose/street car.. An advanced driver with a basic track setup doesn't need -4 (and all of the hardware to achieve it) to be successful on an RE71RS or similar. If you've got all of the suspension, all of the aero and all of the power then yeah...

 

[garudathree]

The key distinction here is full-on race car vs dual purpose/street car.. An advanced driver with a basic track setup doesn't need -4 (and all of the hardware to achieve it) to be successful on an RE71RS or similar. If you've got all of the suspension, all of the aero and all of the power then yeah...

nope, the red one is a daily. only aero and suspension mods. you can see the front plate as well.

keep back tracking?

 

[AHP]

nope, the red one is a daily. only aero and suspension mods. you can see the front plate as well.

?‍

 

[garudathree]

your call, generally an inability to accept new views that are researched and tested is what will keep you from being an advanced driver. you can certainly improve your outside shoulder wear just by switching to a faster tire...by scrubbing less at the same speed, when you don't take full advantage of said tire.

 

[Todday1]

Where did you end up on the rear with -4 in the front.

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