We race a 2T on an oval track and run in 2nd from about 3500RPM to about 6500RPM. We could only find 46mm o/s pistons regretably with 2mm top and 2nd rings instead of 1.5mm. I notice all high performance motors run 1.5mm rings and smaller. I have found 2mm chrome rings locally so we don't have to run the cast iron rings the piston came with.

My question is how much difference is the 2mm ring going to make compared to 1.5mm in a race application? Your input / comments would be appreciated.