Even I could tell that there was quite a difference in grip between my qualifying session (second session) and my race (eighth session). It didn't help that it was bloody freezing on track itself, so the track temperature can't have been very high at all. I was cold even in my race suit
For the race the top 6 were sat in their karts at the exit of the pit lane for the last 5 mins of the race, then positions 7-10 got karts fresh from the previous race. I'm good at these racing driver excuses
Apparently the Bristol ones are pretty new (obvs don't know about the Cardiff ones, altho apparently we might be going there soon :tilt
so there doesn't seem to have been to much difference in the ones I've driven certainly in terms of outright lap time, but there's definitely some with interesting characteristics - the one I drove in the Round 1 race just drifted everywhere 
) He tightened up the pin to hold the brake pads in, in like 7 Celsius temperatures.. I presumed the calipers expanded when they got hot and snapped the pin 
closest I've been too a good kart was dmax at start of this year :|