Suggestions for alignments settings on 255 40 17's
 

For several years I ran summer performance tires in 245/45/16 on stock FD wheels in PAX autocross and used Pettit's autocross alignment settings for 16" wheels here:
https://www.rx7club.com/3rd-gen-arch...-specs-182680/
I've since all but given up autocross and a couple years ago I pulled the trigger and moved to a set of 17x9 wheels for my car when 245/45/16's became near impossible to find. I've been running summer performance 255/40's since. Since the car is 90% + street driven these days, I'm wondering if there is a more optimal alignment setting for 255 17's to optimize handling and tire life. The -1.8 camber seems like a lot and despite a decent wear-rating, I only got a couple of summers out of these tires. Should I go with Pettit's settings for 17" wheels (-1.3) or does the 255 width require something less on the street? If anything, I still have a bit of over-steer with a slightly stiffer-than-stock (adjustable) front sway. I am so not verse in these issues, so any input is welcome. Thanks.

Hey Jim,

If you don't plan to autocross the car, then I would just go with -1.3 degree of camber in front and less negative camber in the rear. It should still give you some decent turning performance and your tire wear should still be ok with the amount of driving you do per year. I autocross my car and I have -2.5 degree of camber in front and -1,8 degree in rear.

Thanks James. And good to hear from you.

What he said. Somewhere around -1.0 to -1.2* front and about -0.8 to -1.0 rear.

Depending on what you are running for toe links, set rear toe-in between 1mm and 0 or so. Stock toe bushings are designed to deflect a bit under braking iirc... Damn memory...
A bit toe in gives a touch of stability in high speed sweepers and under braking.

^Thanks. Running stock toe-links with OEM bushings.

I ran -3 front -2 rear last year, Michelin PSS 245F/275R on the street and Nitto NT01 245F/275R track and street. For an all-street setup I think I'd still want at least -1.5 front and -1 rear.

FWIW, on my S2000 I got 20k miles on my last set of Hankook RS-3s with -1.25 front and -2 rear. Camber wear was not an issue, really.

I run around -1.8 camber front, -1.3 rear.

I don't notice much camber wear on my old tires, 265/35/18 Kumho XS.

I was running -1.5 and wear was VERY even ,

I now switched to a more performance based -2.6 and lets just say its noticable howmuch it eats the inside only 2k miles on the tires and I can tell quite the difference.

it would also be a good idea to rotate your tires fronm left to right , in order to combat that camber wear IF you still get it . with what ever alignment you decide to go with

Tires are directional, so they can't be rotated. I do move them occasionally front to rear.