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supercharged 4.5 liter

Justpunchit

NAXJA Member #1291
Location
Jaffrey, NH
as of right now in my 95 xj im running a 4.5 liter stroker engine with 10:1 compression ratio im looking into getting a supercharger, now i went on avengers website and they said 4.5lbs of boost on stock engine, well ok so what should I be looking at doing with a stroker engine besides lower compression pistions, or should I even be worried about my compression ratio being this high? I was going to put this in the street performance thread but my rig is not anything for the street
 
X2 on the compression being too high to start off with. If you can find some 8.5 or 9.0:1 forged pistons, that would be your best bet to start off with. If you are able to tune it right, pump gas won't be an issue. Might want to look into getting a better than stock replacement head gasket also, just for insurance. 4.5 psi isnt a whole hell of a lot, but look into a programable timing retard setup and bigger injectors or a 7th one that is activated at full throttle.
 
with going to a bigger injector like to the 5.0 injector swap, should i be going to a new fuel pump? and i kinda figured my compression was to high, what about renforced bottom end? i just went with a mopar crank nothing performance when i did my build, well thanks everyone for the advice as always
 
JJacobs said:
Well, you could always rebuild the fuel system and EFI to go E85! Probably a lot easier to change pistons though.


even better. leave the compression there, crank the boost way up, and go to propane.
 
Whoops, I meant change the computer to something capable of running E85. That's very likely what I'm gonna do with the Comanche soon. I have a wideband that'll tune alcohol and injectors big enough to support the engine. This one won't be blown, though; E85's cheaper than race gas and will support the 12.8:1 CR.

I hear boost coolers spraying nitromethane work well, too. :firedevil
 
It all depends.

You could run 10:1 compression, but you need to keep your inlet air temps reasonable. So you should look into either an air to air or air to water intercooler. And you can't run too much boost, but it should run strong.

My turbo Formy has a custom 8:1 setup, my stock compression was 10.1:1.
 
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