im currently running 4lb boost(509 intercooled, good heads, blower pistons, cmi sport tubes 8-71 blower shop blowers) my question is, when i move my boost up to 8lbs will my rpm's increase at wot. currently at 5000 if so how much ??

Yes, you RPM's will rise! Its hard to say how much depending on several factors! Boat weight, FUEL, Prop,type of boat, ect! It wont be allot! On one of my Twin Turbo motors "Remember boost is boost" I have an adjustable wast-gate! I could go from 0 to 30 lbs of Boost on the fly. 0-20 I would see a 1800 rpm climb! I called it "turning up the volume"!

Bryan

you will definately gain rpm's,i would expect going from a 4lb pulley to a 8 lb pulley will give you a signifigant increase. 4lbs should give it another 100 hp even taking into account the extra friction&parasitic loss,400-800 rpm's depending how loaded down your hull is/prop etc,Smitty

Cafe,

Just curious. What cabs are you running, Jets. Power valves, are they boost referenced?

Don't forget you will have to Re-jet and most likely prop change!

Thanks

Bryan

i believe the carbs are 750's worked and boost referenced by c&j ???. dont have the jet sizes here with me. i think 84 72 i dont remember