After racing a 1.8 SM for two years I can say with much certainty that a 4.1 is not optimal on any of our tracks here in the SE. You want at aleast a 4.3 on any of the tracks we race in the SE I would think. You would want to go to a 4.77 at RA as it is straight drag race out of turn 7. Maybe even the same at VIR because of Oak Tree.

I agree with Bowie that with Roeblings long sweeping corners where you have to be smooth, you probably want a taller gear, but I still think that 4.1 is a little too tall. I have raced against a similarly prepped 1.8 with a 4.3 and the difference was noticable.