I have my Indy set up a while back now and it was great.

However after a bit of fiddling etc and a change of tyres the car turned to crap.

I managed to get the front pretty decent again as it had horrendous understeer.

However I cant get the back end sorted, even going slow into corners it is sliding all over!

I'm not sure which direction to go with it.... more camber? less camber? more or less pressure? (19psi)

Can anyone suggest what sort of camber and pressure I should have?

195/50/15 R888

I run my 888s at 16 psi max

On camber mine is set at zero, with half a degree toe in. Like Lewis I run my R888s at 16 psi on the road.

I run 13" wheels though which is a lot better IMHO.

[Edited on 30/9/15 by SJ]

Minimal camber and tow. On the rear tow in will make a massive difference, fells almost like having 2 flat tyres. It just washes out without invite.

R888 are cold 18PSI for me. A deg here or there in not going to make a difference.

Check you have free movement and nothing is binding at the rear.

Changing wheel size would not make as much of a difference as changing tyre grade.

I don't think the toe is adjustable on the rear of mine?

Good that you mention to check for something binding.... I suspected a rear brake was binding last time I was out but forgot to check it when I got home.

I put maybe 1 to 1.5 degrees camber on the rear to help balance out the positive camber when cornering... Is it better to leave it with no camber and just let it do its own thing?

Thanks

1 degree worked on mine, with 14-16psi. I found that the car was very fidgety on any more than 18psi.