My old RST was chipped - 170ish bhp and I would stay with Karl Norris in his 205 Mi16 with no difference in acceleration until an indicated 135 on both clocks.

Personally when I had one I wasn't that impressed it felt gutless compared to a Turbo car.

Where they really win is in the handling dept (if you can drive em) as they're light and stop well.

For a tear up around the lanes or point to point between islands they're a bloody good laugh though.