[GTOGEORGE]

internet searching,

When you advance and retard the icl you are altering the dynamic compression ratio also. Too much advance can create too much cylinder pressure which will create detonation issues unless tuned around or a higher octane fuel is ran.

Retarding it does the opposite which will lose power and lower the dynamic compression.

Instead of just crutching a centrifugal like you are saying with advance you would use all of the cams specifications like duration and lsa to create the power band you want and not just relying on ICL advance.

Same with a roots supercharger, use the other cam specifications to create the power band you want.

The other thing you're missing is the intake manifold and cylinder heads. They will also play a big part and most of the time even bigger part in the RPM range that peak torque and horsepower are made in.

A set of stock cylinder heads and your intake manifold that is apart of that blower no matter what the cam timing is due to the runner length, plenum volume and runner design just won't make anymore peak power past 6200-6300 as Pred Z said.

That is why people will change out from the stock style type intake manifolds on say a nitrous car or a N/A H/C/I car to a single plane so that they can rev the motor higher while still staying in the peak power range of the motor. This is achieved by the shorter runners in the single plane and more plenum volume.

Your intake has long runners and less plenum volume therefore making it limited in the amount of rpm and peak power it can make along with making a lot of usable low-mid range torque.

GTO George