88GT HP Estimate?

Mach428

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Dec 7, 2003
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I just wanted to see someone elses opinion since I can't run out to a dyno. Does any one know the aprox gains on a full exhaust and cold air? Exhaust> Flowmaster A/Thunders, BBk Catted X, BBK Shorties - BBk Cold air, Ford Racing 65mm Throttle Body next... :spot:
 
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you can't really tell, some cars baseline (stock) at 190RWHP, and some do 215 RWHP like me, stock...

usually the 87-88 5.0's are a little more powerful when stock due to the speed density system...

IF you were making 200RWHP stock, You should be around the 225 RWHP + mark, maybe more, but peak power isn't the main thing, it's the average power your gonna get from doing those mods...

I also suggest you advance your timing to 14*
 
5spd GT said:
Well I wouldn't say "TOPS!!!" but it will be somewhere in there...more or less...

David
I would....but don't get me wrong. Exhaust systems, T/B's and CAI's are great, and have the potential to increase horsepower by 20, 30 or even 50hp on the right combination, but without a better breathing intake and/or set of heads, the numbers fall far short of manufacture claims. I've seen a dyno run on a '95GT that gained only 3hp with a full exhaust. You can open up the intake and exhaust track all you want, but all that incoming airflow is going to hit a wall when it gets into the anaemic stock intake manifold and heads. Nope, I still say no more than 15-20hp at the flywheel.
 
Well "opening up" the exhaust on my car with stock everything was definatly more than 3 horsepower....now if you changed your "fwhp" to "rwhp" TOPS!!!...that would be more like it....it would be NO MORE (full exhaust, and 65mm TB) than 15-20rwhp...:nice:

My opinion that Cold Air didn't do nothing on his car... :notnice:

David
 
I bet most people would be surprised how little their cars actually make on the dyno after these mods. Seat of the pants feel, or thinking it's faster cause it's louder is one thing, but solid horsepower numbers are another. But hey, who am I to argue, I don’t’ have a dyno in my garage, but I have seen guys strap on a hell of a lot more parts than that and come up way shorter than they’d expected.

Mach428
The intake would help some, but after that, the real problem in this equation is still going to be your heads. A 70mm T/B will do nothing at this point, nor will the 24lb injectors. As a matter of fact, the 65mm will flow up to 400fwhp, so jumping to a 70mm really won't change matters better heads, or not. What you’ve really got to do if you want to make any real power is start saving up for a port job or aftermarket heads and intake. Then worry about the smaller secondary mods like Throttle body, exhaust, cam , etc.
 
Thanks Mav, Nice jump in performance, but keep in mind an EFI engine and Carbed engine are two totally different animals. Not to mention you went from a stock single exhaust with dual tail pipes, to a true dual 2 1/2 in set up. You're gains would be considerable compared to the average EFI 5.0L.
 
w/ stock heads and a blower, you'll probably see more boost, but that definetely doesn't equal more power. Say you were runnin 9 lbs of boost w/ the stock heads, w/ aftermarket heads that boost may drop to 6-7, but your motor will be runnin much much cooler w/ much less stress on the drivetrain, and still make more power then the original 9 lbs of boost.
 
Mach428 said:
Just another noob question. In the future we were considering a s/c. Without port and polished heads will the s/c not gain its full amount of HP & TQ?
In a word....No. Think of it as trying to breath through a McDonalds straw (stock heads). If you really start to breath deeply (the addition of a supercharger), you're going to move a little more air, but you've got to use twice the effort. Now, change that to a garden hose....it's a lot easier to breath and when you start breathing heavily, you're moving a lot more air.

Small port/valve stock heads work well with a stock motor because they keep velocity and airflow high, but even in the E7TE's case, they're in desperate need of improvement. A good port job or a switch to aftermarket heads/intake will allow you to take advantage to any other mod performed on the engine.

In short, is it necessary to port/change the heads/intake when supercharging the engine....no. By not doing so, are you getting anywhere near the power available to you.....not even close!!!