Slug Catcher

Shorties do make more power, especially equal length Shorties.


The reason they get a bad rap is that people only look at the Max Hp numbers, and not the entire power curve.

Shorties make their power increase in the mid range "3000-5000 RPM", But the extra power fades away at the higher RPM's because of the cats.

Long tubes dont make much more power at the lower RPM's then the shorties do, but they keep building power all the way up the power band. 5500-6500 RPM's is where they really make the power.

Thus, If your only looking at maximum hp you probably wouldnt be too impressed with shorties.

But how often are you at 3000-5000 RPM's compared to 5500-6500 RPM's?


Long tubes are still better, But Shorties are still better then stock.

Shorty comparison with stock numbers "on an old 5.0"------>http://www.allfordmustangs.com/Detailed/118.shtml



Heres what Im talking about...... An article that compared a 4.6 stock exhaust vs. Equal length shorties, Note that they removed the cats like you would with long tubes....
http://mustanglife.tenmagazines.com/...ticle&aid=3406



I also found this.....https://mustangforums.com/forum/gt-s...o-results.html

I think JBA says they give a 22 hp increase over stock at the mid range.... Kind of seems like his Dyno confirmed it..... But I dont know 2 dyno's months apart with diff gears is pretty if'y.

Diabolical!

Here's the skinny. Those articles claiming crazy HP numbers from exhaust components alone are not telling you about the tuning that goes into getting those numbers. Those numbers are achievable with the stock exhaust and the same tuning. If you want to buy exhaust components for looks or sound, then by all means, go right ahead. Don't listen to the advertising. You won't make any HP by changing the mufflers, mid-pipe or shorties. The only way you're going to gain power on the 3V with exhaust mods is if you are already making crazy power through boost and need extra room to flow. Even then, you'll need an entire exhaust upgrade with bigger diameter longtubes, collectors, mid pipes and over-axles in order to see results. Take my posts as you will. I'm trying to help people who are looking for performance mods to save money. I don't bash parts just because I don't have them. I give honest reviews based on my extensive (non-internet) research. I could go out and buy a set of shorties tomorrow and not miss a dollar spent, but I won't.

Simon1

The article wasn't too helpful. It lacked details I would like to see ina comparison test that I see done in other comparisons.

The best way to get real results is change only one thing and test.

I'm still not convinced either way. Logically, an equal length exhaust with bigger primaries will flow better because of scavenging, but logic doesn't make horsepower.

I would like to see a magazine put an S197 motor on an engine dyno and swap stock exhaust manifolds with different brands of shorties.

Diabolical!

So would I. My information comes from the tuners themsleves (I asked many when I was planning my build). I wish someone would put some before and after results in a format that would ultimately put the argument to rest. For the time being, I'm going to stick with the advice of the guys who do this for a living.

pitch

Well thanks to all for the info. I also talked to a couple of Mustang builders/experts. They said pretty much the same thing as Slug Catcher said. Equal length shorties will help some at lower rpm's. But they estimated roughly 3-5 horsepower at those lower rpm's.
But as I said in the beginning this is about cosmetics. So again, thanks for all of the advice.

SCCAGT

I ultimately made my shorties purchase to help flow better than a factory manifold. I avoided long tubes because I didnt not want ANY mil issues arising from missing O2 sensors, or wiring extensions. I wanted it to be as hasslefree as possible while getting a moderate gain of power and sound quality (not volume). Ceramic coating maintains the cosmetic portion as well. Shorties fit the bill for me. Havent looked back at all to think I shoulda/woulda/coulda with LT's.