Recommended track day tire size?

[JayG]

Go with 17's. They are a bit less $$ than 18's and no difference in performance
additionally 17" wheels may weight a little less that the same in 18". Same with the tires

RE$-71's are the goto tire. Just don't expect a long life, especially with a stock suspension as they are severely camber challenged.
You will see lots of wear on the edges

[WindS]

Thanks - really helps. My suspension is stock. Maxing out negative camber, but something is wrong in the back - can't get full -1.5, more like -1. Car is for racing and is a little banged up. Has the sport suspension 030 option!

Looks like the RE-71R can be swapped left to right. should help.

[steved0x]

Originally Posted by WindS

Thanks - really helps. My suspension is stock. Maxing out negative camber, but something is wrong in the back - can't get full -1.5, more like -1. Car is for racing and is a little banged up. Has the sport suspension 030 option!

Looks like the RE-71R can be swapped left to right. should help.

Something must be wrong back there, as I am not sure I could get to "just" -1 with my stock suspension, I was able to get up to -1.9. That is a pretty big gap. Can you share a picture that shows your rear camber eccentric along with the rest of the suspension on one side? Maybe that might reveal something?

[JayG]

About the only way to get real camber is to go with GT3 control arms. They are $$$

A good lower cost solution is to get the ROW 030 springs and add camber plates for the front
I run that setup M030 ROW struts and springs and tarret camber plates on the front
I get front -2.2 and rear -2.5

It made a HUGE difference in the car.

With GT3 arms, you can get camber in the mid to high 3's

[BrantyB]

Not sure what group you're planning to AutoX with, but check the rules because camber plates with PCA puts your car in a class you won't be competitive in. GT3 LCA's are great, but not close to free.

For autox I would suggest 18" wheels so that you can get the widest rear tire possible without losing sidewall stiffness. And you won't need to change sway bars. The car will have understeer, but I find that more useable than losing the back end. A lot will depend on how you drive the car.

RE-71's are terrific. You can flip the tires on the rim once the outer shoulder wears. I got over 100 runs from the fronts (50 before flipping). Rear outer shoulder is now spent, but I can flip and have enough tread for another season. The car has mild camber with 2*F/2.2*R because it sees a lot of commuter time too.

[JayG]

Originally Posted by BrantyB

Not sure what group you're planning to AutoX with, but check the rules because camber plates with PCA puts your car in a class you won't be competitive in. GT3 LCA's are great, but not close to free.

For autox I would suggest 18" wheels so that you can get the widest rear tire possible without losing sidewall stiffness. And you won't need to change sway bars. The car will have understeer, but I find that more useable than losing the back end. A lot will depend on how you drive the car.

RE-71's are terrific. You can flip the tires on the rim once the outer shoulder wears. I got over 100 runs from the fronts (50 before flipping). Rear outer shoulder is now spent, but I can flip and have enough tread for another season. The car has mild camber with 2*F/2.2*R because it sees a lot of commuter time too.

I personally prefer oversteer to understeer. At least you can rotate the car. With a stock suspension, yea, the Boxster is a great handling car, but the difference is dramatic with mods and the right alignment. It goes from great to super-duper

Yea, you go from a stock class to a points based class. In theory you are classed with cars that have similar performance. At the end of the day, it all comes down to the driver.

Putting GT3 control arms would also put you into a point based class. Yes you do get a lot more camber. You really need to look at the entire suspension together as a system.

I humbly disagree that 18's are better for AX. I suppose the slightly shorter sidewall may make a slight difference, but you will be paying a lot more for tires. I would go with 17's and save the $$

[Topless]

It does depend a lot on your local ruleset but here in SoCal I preferred running 17s. I liked 255 square for tight AX and 225/255 for the track. I did run square for a while at the track, but the data was pretty clear and favored 225/255, especially at Fontana and Laguna Seca.