Learned a lesson today - Pilot Sport Cups need neg. camber

[EPIQTodd]

Had a GREAT day at Buttonwillow today - ran several 2:10's (which I came to find out was pretty darn good for race 13, clockwise, which is what we ran). Had two nice GT3's there and two new Z06's, plus one fantastic driver in a turbocharged E36 M3 that was as fast or faster than the GT3's, which both had great drivers, too.

Anyway, despite 'only' about 150 miles of track time (!!!) I had to cut my day early, at about 3:45 because one of my front PSC's corded. This after two days at Streets of Willow and this day at Buttonwillow - that's it. There is plenty of tread left, and the rears are wearing beautifully (and yes, I did the correct pressures, and checked after each run, and have all the input from Michelin's PSC research/presentation) because they have 2.5 degrees of negative camber, but the fronts have only .5 degrees negative so far - max for stock strut towers. Michelin states that PSC's really need 1.5-2.5 to be happy, and it is true. Soon the camber plates I commissioned to be created for the Boxster will be completed and I shall champion the resurgence of more track miles on PSC fronts! I shall be victorious, and have more money in my bank!

[986Jim]

hahah. Cool, sounds like you really had a good time. I would be interested to see the plates before you install them, maybe I could fashion a set on my mill with some pics of yours for my car. I have yet to get my car to the track being a new owner and all, but have some experience setting up a road/race car and I just dont wanna show up with a stock car that will do wierd things on me.

I'm not surprised that you corded the tires that quickly however, the fronts really take quite a beating at the track, but after only 3 events? Thats seriously fast...

[EPIQTodd]

Originally Posted by 986Jim

hahah. Cool, sounds like you really had a good time. I would be interested to see the plates before you install them, maybe I could fashion a set on my mill with some pics of yours for my car. I have yet to get my car to the track being a new owner and all, but have some experience setting up a road/race car and I just dont wanna show up with a stock car that will do wierd things on me.

I'm not surprised that you corded the tires that quickly however, the fronts really take quite a beating at the track, but after only 3 events? Thats seriously fast...

Actually, it's not that fast. PSC's are designed for 1.5-2.5 degrees of negative camber, and I had .5 on the front. With about 250 track miles of hard driving, the cords are gonna give way because the edges are taking too much stress without the proper camber.

[986Jim]

So you figure you could double the life with proper front camber?

[EPIQTodd]

Perhaps not quite double (which we'll call 100% more), but at least 70% more, yes.