I´m building a low budget sprint race SuperBravo for a local event next spring.
The race distance will be only 75 meters and I need one advice from you who have more experience:

To achieve the best acceleration I might get some different rolls to use in the tryout but which weights is likely the ones I will need?

The setup is like this:

* Cylinder will be a Dr Evo 43 millimeter or a Malossi DEPS 43 mm (the regulations says maximum 70 cc´s so a 46 is out of the question), I have these two cylinders and time will tell wich one I will use.

* Side intake with reed valves combined with a 17,5 or 19,5 PHGB carb, again time will tell wich one I use.

* Exhaust will be a Polini Top One

* I plan to remove some material from the flywheel to lose some rotating weight (CDI ignition)

* Malossi variator, this is delivered with 4,7 gram rolls and this is of course where I need your support.
I can get Malossi rolls in weights from 2,7 grams up to 10 grams but I think I have to go lighter than the 4,7 to increase the revs where the variator beginns to work and this is where I need your experience.

Have anyone tried the lighter weights or have you all went for higher top speed using heavier weights?
What weights would you suggest that I start with or wich ones to get for a tryout session?