try a 6mm or 7mm restrictor, it smooths the powerband out alot... I have a 2 gal old vspec that routinely smokes speeds all over the track cause theyre blowing the tires away.
My vspec setup:
13/46 gearing big tracks I'll run 14t bell
RC8 clutch
1.0/.9 springs depending on traction
stock alum shoes
6mm TKO restrictor
EPA limited about 20%
JP4 pipe
P3 plug
TQ 30% fuel
gets 11-12 mins runtime and fast as anything