cobra_fanatic said:
Yeah I'm wanting to go the centrifugal route. And as far as my CR I'm not sure. Everything is stock except the pistons are a 16cc dish. All other measurements would be stock but I'm not sure what they are. And I have the B heads. I was *hoping* I could run 12-20 psi.
I think there are other questions here too, as in what do want the car to do? Having the biggest BHP numbers will cost loads, probably be unreliably, certainly not very usable on the road and not nesecarily the fastest at the track either.
If its just massive bhp and track use maybe consider a different engine altogether, as you are limited by cc and general design of the engine.
If you want big usable power then a twin screw blower would be your best bet, lower peak numbers than a centrifugal but more power more of the time.
A Turbo setup would be cool, but very pricy and the comp ratio you have (not sure what it is exactly) is still WAY too high for really high boost from a turbo, the downside is if you lower the CR further you can add more boost, which should equal more power, but it also means when you are off boost you have no power at all, a higher CR will mean less boost and potentially less peak power, but it should have more go when in low/off boost situations.
Have a look here
Kenne Bell twin screw , do remember as your CR is lower you will not have as much power now so your increase will not produce the same numbers either (the % increase should remain though). With a slightly lower CR you should be able to run a little more boost and be as safe and produce the same or more power.
Here is a good article from MM&FF they built a high CR and low CR 4.6 mod and bench makred them as n/a and with a supercharger. They ran exactly the same spec on each except for the CR. The low CR unit produced around 10% less power, it would have been nice to see if they could have gotten more from it by raisng the boost.
MM&FF article