supercharged 4.6l ?????

stang869846 said:

so ur saying that just take p.i. intake and put it up to my n.p.i. heads? i thought they wont match up? and i didnt think that around 300 rwhp was to bad for pretty much a bone stock car stock exhaust manifold, throttle body, intake plenum, was to bad i mean hell these cars only make 180 rwhp stock and the supercharger added over 120 rwhp i mean i think thats pretty good i know it seems low for a blown car but i need to get it breathing right with headers bigger throttle body and heads and it needs to be intercooled too. but do u think if the tuner took alot of timing out of it because of the 12psi i could drop down to 8psi and see higher number is that what ur saying? would the more timing with the 8 lb pulley make more numbers than the 12 lb pulley and less timing? just curious.

Click to expand...

With your current set up, you could probably drop down to 8psi, have it retuned and make the same or slightly better numbers....yes, that's what I'm saying. Even spinning the blower as hard as you are, most of that additional volume of air is being backed up within the intake track and isn't making it into the engine. Not to mention being superheated. To give you an idea, most '99-up guys running 12psi (with some sort of aftercooling)through their stock cars with no other bolt ons are seeing in the 420rwhp range.

Like I said, the PI hardware in your current NPI heads and/or having them ported would be the way to go. That way, you get all of the flow benefits and compression ratio remains in the 9:1 range. The PI intake will bolt up to the NPI heads. All you need to do is run a thin bead of RVT around the water/port passages of the head along with the PI gaskets to guard against leaks. Literally hundreds of pre-99 Mustang and T-Bird/Cougar guys are doing this with 100% success.

If you're still not comfortable with that idea, Fox Lake Racing will open up and port a set of NPI castings to the same port shape and flow potential as a set of Ported PI's. There's enough meat around the ports in order for them to do so. If cost is an issue, keep in mind that the money you would have sunk into buying a set of PI heads will pay for over half of the port job. In the end you'll make more power with a set of properly ported NPI's that you will with just a strait PI swap. As for the rest of the cost.....a set of good flowing heads and intake will yield you more gains than pretty much all of the other bolt-ons you previously listed put together. Hell....cams alone will run you about $600....and with the kind of compression ratio a PI swap brings, all you're pretty much going to gain out of them is a lumpy idle.