Polini clutch springs

[NrgPower50]

Hey, have bought some polini clutch springs for my 05 Nrg Power a/c (Derestricted, 5.0g rollers, leo vince zx) because im having problems with it bogging down before 7000rpm and not moving, i have 4 sets of springs, red,yellow,blue,black and was wondering which do i need to fit for better acceleration as im not to sure, thanks a lot

 

[david14a05]

i am not sure what colour but the stiffest ones will engage clutch later that loser ones. giving you higher rpm when your clutch engages.