hey guys, i have a 98 cobra(with only 40000KM) with a p-1sc procharger that have a 3.60 pulley gives me around9psi on my gauge, and the beast is equipped with long tub headers and xpipe with cats and a side exhaust pipes and some other bolts on with the stock engine. My questions is i would want to run more boost is a 3.40 good idea, and my gears are 3.73 would it be better to have 4.30. And some people tell me that my side exhaust makes me slower or loose some good power is that true? in the next week am going to tune it with a tuner on the street not on the dyno is that enough to have it "will tuned". Guys how much power you thing am making??? appreciate your help!

 

Your supercharger is heavily reliant on rpm, so switching to 4.30's will keep you in higher boost while your racing... but a bit too much IMO for a daily driven street car... and it will suck doing roll ons for highspeed (140mph+)racing...

for your stock engine, i would not do more boost... 3.60 pulley is as low as i would go, unless you dont mind sacrificing a lot of reliability...

as for your exhaust, i would have to see HOW its routed...