Bigpower

OK,

quick question...........

its my belief that improved exhaust flow (manifold) will not affect the boost level on a supercharged engine as its after the combustion process (opposite of a turbo where better exhaust flow increases boost/power)

I also think that a bigger intercooler will increase boost as will a induction kit/improved cold air flow

however its my belief anyone with more knowledge than me got any more info ?

why i ask is i have some manifolds that increase power on a N/A IS250 by 32 bhp and I'm hoping for + 40 bhp from my supercharged IS350 if i fit them. BUT the all alloy engine is not allowed past .4 bar and i'm worried this could do that...........

thanax for looking

You are correct that exhaust flow has no effect on boost levels with a Supercharger. A supercharger is belt driven from a pulley on the engine, it has absolutely nothing to do with the exhaust. To change boost levels on a supercharger you have to change the size of the pulley that drives it. There probably are other ways as well but none involve exhaust gases.
Thats the way I see it, someone may correct me.


Chris.

Going for bigger diameter outlets on an aftermarket manifold makes power as does going for a large diameter exhaust to loose to gasses as quickly as possible.

A bigger intercooler will lose boost pressure as there is a larger volume to fill and a SC will only move a fixed amount of air for every engine revolution, plus the cooler air is more dense.

What sort of supercharger is it fitted with and what bar is it running now?

running .4 bar with water to air intercooler

can't do more than .4 bar

How come they can only do .4 bar standard. Has anyone tried to go higher?

Only way to make cheapish power is to change the exhaust/manifold for a really free flowing system. After that sounds like built engine time.