Originally Posted by AW106

Depending on what surface you race on I've heard good things and seen goos things of the Surpass v4s for carpet. For outdoor on longer tracks where you want revs the R1 V21 is popular. If you want something a bit different the SMC low rider was equal if not better on KV than the R1 in a test I watched and I've loved running the motor personally
For options this is a guy who runs a small shop in the UK and does some of the most detailed motor reviews I've seen
https://www.youtube.com/watch?v=uUbHBAy9iyg
https://www.youtube.com/watch?v=xlWHrcuRd1Y