Are 17" alloys a major no no with BEC's. what would be the downside to using 17's over 15's and do 17's fit under front and rear arches? my car is running a 3.62 LSD diff and has 2001 carbed R1 engine.

get the diff changed 3.38 or even better 3.14 the bigger wheels will give better top end very slightly, but they will dull the accleration. dont know what it will handle like with them on either the ubsprung weight could be an issue.

3.14 is supposed to be a bad choice for carbed R1. a guy on here told me that he had one which did 80 mph in first

no expert on r1 engine i would have thought a 3.38 would be better suited the 3.62 i had ran out of puff at 110 changed to 3.14 now off to rockingham tomo so i will see what happens driven it on the road and it feels about right for thet engine. never been a fan of big wheels on kits i think some nice 15s look more in proportion but its personal choice.
rob

cheers mate.i will stick to 15" wheels. its just i saw some very cheap pro race 2's and was wondering what they would be like.

i would sat too big ran 16's and now gone down to 15's ( not run them yet )you need a good bit of sidewall in these IMHO.

regards

Agriv8

I have 17"s on mine with a 3.62 diff and it runs fine, i had thought about going down to 15"s but only to reduce unsprung weight. People do say that when a car with big wheels lets go you struggle to catch it, having said that mine has been sideways a few times and it is still in one peice, one plus point with big wheels is more rubber on the road.

I might be rather biassed (just a bit) but change the diff and if you dont want to stretch to R888s go for A539s from Polleysport.