Tyre wear analysis needed Toyo R888s on our race car

[B_giB]

How are the rear tyres wearing? Any pics?

[Bazda]

+1 for rims being too narrow.

The narrow rims will be pulling the sidewalls in, and the center of the tyre will be ballooning out.

May not be visible, but during hard cornering the tyre flexes a lot, and if its not sitting as flat on the rim as possible, you will run into issues.

Look at how much a tyre flexes during cornering: http://www.youtube.com/watch?v=v-DMkO3g2SI

Now imagine your rim being too narrow, it isn't going to support the edge of the tyre of optimum grip.

If the rim was too narrow the side walls would also be worn quite bad as the tyre rolls over the edge. But looking at the pics this doesn't look like the case.

Like I said I ran the same tyre, same rim width. Never had an issue and got really even wear.

[85AW20v]

Seeing as you've got the springs, try the 8's in the front and then the 6's to see how it goes. With the problems you've got. it's not going to hurt to try.

Usually to reduce understeer you need to stiffen the rear or soften the front to transfer more wieght to the front. To reduce oversteer you soften the rear or stiffen the front.

I don't think a front swaybar will help the understeer issue at all but might reduce bodyroll.

[Emperor]

Use them on my RX7 (Pro 7 / SS2000), never had that issue heh!
Most of the time (our series is summer), I've run them at 22psi at pukekohe and manfield.. Taupo a little harder.

I'll go have a look at our old sets, but don't think they look that bad.

[85AW20v]

You might also want to have a read of this. Might help with your setup and tire wear. The theory behind it is the same for race tyres as street tyres, just the psi ranges will probably be different.

http://www.turnfast.com/tech_handling/handling_pressure3

Playdayontrack have got an event at Hampton Downs on 4 August which would be good to sort your tyre pressures as you can make changes and go in and out pretty much all day without being in a practice/race situation.