Hi All, long time since I last posted!

I’m putting a 1999 SEIW hillclimb car back on the road and getting it ready for an MOT.

It’s currently got 7x 15” Oz superleggra alloys on it with 205/50/15 tyres.
I’ll keep the 15’s for road use, but I’m adding a set of 13’s for track use. I’ve picked up a second hand pair of 6x13 compomotive CXR’s for the front, which I’m happy with, and will be ordering rears to match. The car has a 265bhp duratec with around 200ftlb so I’m looking for slightly larger rears to deal with this. I don’t want to screw up the balance or handling however, so wondering whether to go for 7” or 8” rears. Ive got detachable rear arches and from rough measurements, the 8” will fit.

Looking for feedback on what others are running and also optimum tyre widths.

Thanks in advance.

Caterham Standard set up for around that power is 6 inch fronts with 185 Avon ZZR/ZZS and 8 inch rear with 215 ZZs/ZZR if that helps.

I run that set up with 235hp on a Caterham.

Cheers

Ian

Thanks Ian, that does help. It’s 185’s I’ve got on the two 6” fronts so would be similar. I just don’t want to end up turning a well balanced car into one that understeers like a pig due to far more rear than front grip. I know there’s more to it than just tyre widths, but do you find the tendency for understeer with this setup?

Drives great, 185s I think are too small for your power...