Originally Posted by Ekskaar

I've had the chance to put the car with 21" wheels to the ultimate (to me) test onthe Dutch F1 racing circuit.
it was not bad at all, the tires circumference was bigger than standard, with some effect as expected..

Good: better in getting the power down, much more grip (315-30-21 CUP2) in the rear. Easier to throw around in less carefull manner without having the nose of the car directing in opposite direction;-).

Maybe less good:
the 315-30 rears ate up the wheel liners when pushing for fast laps

And although the standard brakes with Yellowstuff held up well, I felt I needed to stand on the pedal with more force. Did not enter in ABS activation.
This by the bigger wheel/tire circumference I expect.. (255-35-21 fronts, wanted 30s but that would trigger faults with the big rear tires beyond 5% bigger)

All in all, nice experiment.
Next experiment is electric brake cooling, and back to 19" with smaller than standard wheel/tire circumference. (See if laptimes can go up)

Originally Posted by jahummer

For track (and street), try real track pads like Pagid yellow 29, perfect mix for multi-use. I never had good results with EBC on the track.

Originally Posted by Ekskaar

Not sure how wide your rims are.
But one size widh extra should be possible I expect.
on 20" standard is 255/285 correct?