Quick tire question

[Phantom_9192]

Ok folks, I'm heading to CoTA with my FR-S for the first time. My PZeros got pretty mangled at TWS on the outside edges so I just bought a set of RE71's to put on my 17x7.5 wheels for the trip (225/45/17 like the PZeros).
I added negative camber to the front (from 1.3 to maxed at 1.9 using the camber bolts that were on it) and re-set the toe to a touch out both sides. I'm hoping this is enough to make the tires last longer.

I spoke with several people who recommended the RE71's highly so that was my choice.
Now to my question.

What pressures should I be shooting for? 37-38 hot?
I will push the car 10/10ths. 1.9 negative still doesn't seem like much camber to me but here's hoping.

Let me know ASAP on pressures please!
TIA!

(btw see below for evidence that I will be pushing the car 10/10ths... this car is too amazing to not push to the very limit).

[ame="https://www.youtube.com/watch?v=YDl0bydlsAs"]Scion FR-S Texas World Speedway 1:59.1 - YouTube[/ame]

[CSG Mike]

I would recommend you set your pressure by pyrometer, and get yourself more camber before you go.

[Phantom_9192]

I'll be alone so pyrometer isn't a viable option unfortunately (plus I'm not a big believer in the value of pyrometer readings even on my racecar).
I'll try low 30's and see how that feels.

No way to get more camber without significant modification. 1.9 is where it is. I do worry that I'm going to continue to maul the outside edges of the fronts but we will see how quickly she runs. I'll post results.

[strat61caster]

Most people run re71rs at 30-34 'hot' for autocross, no idea where they would want to be for extended lapping, good luck.

[Shneegle]

I would look at starting around 28psi cold. About 3 laps in they should be closer to 32-34 or higher if you really push. After than its up to feal.

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Stiffen the rear to help it rotate or soften the front to reduce understeer. Since you have whiteline sways it sounds like you could swap the stock sway back onto the front.

[wparsons]

You're probably not going to want toe out up front if you're looking for tire life, 0 toe would also be less nervous feeling.

Originally Posted by Shneegle

If the car is pushing a lot then soften the rear sway or remove it. For autocross its recommended to just remove the rear sway on these cars with stock shocks/springs. Your video mentioned the car was pushing.

If it's pushing and you soften the rear bar (or remove it) you're going to get even more understeer. You'd want to stiffen the rear or soften the front.

[Shneegle]

Originally Posted by wparsons

You're probably not going to want toe out up front if you're looking for tire life, 0 toe would also be less nervous feeling.



If it's pushing and you soften the rear bar (or remove it) you're going to get even more understeer. You'd want to stiffen the rear or soften the front.

Absolutely right, that's what I get for posting at 3:40am was thinking oversteer. You would want the front to be softer or stiffen the rear to allow it to rotate more to get rid of the understeer.