does 2% crank +17%sc need a new belt? need any ecu upgrade or i can just install and run with stock ecu? does it have any effect with altanator with 2% crank install?

 

Are you coming from a stock supercharger pulley to a 17% reduction and 2% crank pulley? Or do you already have the 17% pulley and are only adding the 2% crank pulley?

 

i'm coming from stock setting, and looking to add all the pulleys at one time

 

should i do 2%+ 15% reduction?

 

2% and 15% = 17% effictive at the SC

a 2 and 17 = 19 (some would say your starting to flirrt with danger ....)

belt question ... YES get a shorter one
The JCW belt is shorter as they use a 16 pulley
a 2% crank pully will spin ALL pulleys faster. A smaller pully on the alt wouldnt hurt.

 

thank i will start with 15%