Which Mamba Monster Combo for 8ight on 4s?

[What's_nitro?]

I don't think the 2600 would be that bad. It's only ~39K rpm at most, and that's right at the peak eff% for the Neu motors. The 2200 on 4s is ~33K which is about the same as a nitro motor. Personally I'd go the faster route, even for racing. Top speed can always be adjusted with gearing choices.