347 Stroker Questions

[Pittmac816]

I have a 95 GT with a 347 stroker with Roush Sr. heads, performer II intake and forged bottom end. I am looking at putting a supercharger or a single turbo setup on the car. It is running 9.5:1 compression and my question is how much boost could be ran if it is tuned correctly? Also how much power am I looking at getting with either a turbo or supercharger? I am new to the power adders and I am not sure what one to get. Any help would be great!!

 

[BlackVert]

welcome to the board!

these blocks can handle up to about 500 horses or so before you start worrying about breaking them.

as you probably know, boost is actually only a measure of back pressure. more boost doesn't necessarily mean more power, it means more air backed up trying to get forced through. the better an engine flows N/A, the more air it will flow with forced induction, and the more power it will make with a blower, even with low boost numbers.

if the motor makes 350 horses naturally aspirated, then you can make 500 horses with about 6# of boost. usually, 14# of boost doubles the power output.

what is your goal/purpose for the car?

 

[revhead347]

The compression ratio is a little high, but not high enough to seriously offset the decision to use forced induction. A good intercooler will be the best way to combat the higher compression ratio of the engine.

Kurt

 

[Joe 5.0]

6-8 psi out of a turbo or supercharger will prob put you around 500rwhp, more if you decide to go the meth injection route.

I would seriously consider staying NA and trying to wring some more power out that way, because your block will become a consideration with even mild amount of boost.

Also, what kind of power does it make right now?

 

[Pittmac816]

It pushes out 375 to the wheels now but I am wanting around 500rwhp. I do not know any other way to get that kind of power on NA without going to a bigger motor. The motor only has 600 miles on it right now so I do not want to start over. I want to use it as a weekend driver and a track car. I have other cars to drive daily so I am not worried about that. What is a good block that would hold a lot of power?

 

[1slow95]

Dart block will take anything you throw at it.

Making 375rwhp NA and 9.5:1 compression it won't take much to get to 500rwhp. Probably 5-6# with a turbo or 6-8# with a S-Trim should get you there with pump gas. With your compression I wouldn't go much over that without running meth or 100+ octane.

 

[Pittmac816]

What is the benefit of running meth injection? I have heard of it but I am not familiar with why people run it. Sorry I'm new to this forced induction stuff lol. How large of a mass air and throttle body should be put on if I were to boost it? Also how large of a turbo should I put on the car? 70mm?

 

[bayellowstang]

70mm will probably be too small or run out of steam up top. I'm looking at a 76mm for on mine. We are in about the same boat mine is just over 9.75:1.
Meth injection cools the air charge temp so you are less likely to detonate with the high compression and boost. I will be running intercooled and meth injection unless I switch to E85 if we ever get it around here.