Import-Slaya

Just got my October issue of MM&FF. They installed and dynoed the Bassani and Magnaflow x-pipes, both with high flow cats. Also tested the Mac Prochamber. Dynoed all compared to a stock midpipe. All were using the Bassani axleback.

Gains compared to stock were only 1-2 rwhp and 2-3 rwtorque!!
:notnice:

Very surprised that the gains were so low. Definitely making me rethink my planned x-pipe purchase. :scratch:

eighty6gt

Longtubes.

SixtySix

Doesn't surprise me. Wildstray saw the same results, he picked up nothing much to the surprise of his tuner.

Now someone will chime in and say something to the effect that the computer wasn't given time to adjust. There may be some truth to that. It makes me wonder if there's a way to bybass the computer and see the difference.

97svtgoin05gt

I've read these same things as well. I've decided not to mess with the stock exhaust system. It seems the only real change you achieve by buying exhaust pieces for this car is noise.

Cleveland

unless you buy headers...

-Dan

Import-Slaya

Agreed. Headers seem to be the only real power increase other than complete deletion of the cats. Oh well, that's $500 more into my Saleen supercharger fund.

jvm051

Every report I've seen sofar, states the factory system is very good. How much HP increase could you expect. The factory system only has 2 cats. I am thinking of just getting the Bassani piece that just replaces the X-pipe, for sound purpose.

mikem

offroadpipe is the way to fly...................

Weedo

I agree. If I gained, say, 7rwhp from my Bassani X-pipe and Flowmaster American Thunders, I'd be surprised. Then again, being Supercharged, it could be more like 12-15. But for, what, $750, it was WELL worth the sound even if I LOST 5hp!

StangNut

I would take a look at the actual numbers. The "final" result could be misleading, just like the axle-back tests that were done last month. All the exhaust tested showed little or no gains... until you looked at the break down of the numbers. Every system (except JBA) gained over 20 hp and 40 ft-lbs of torque at 2400 RPM. (They didn't compare the numbers below 2400.) For me, that's exactly what the 4.6L needed, more low end torque.

clockworks

What? Where are you getting this info? 20hp / 40ft-lbs seems like a *huge* amount, esp. at such low rpm...and just for axle backs? I'm a bit skeptical. Just my opinion...and I readily admit I'm a newb, so there is a very high chance that I don't know what I'm talking about. Btw, I agree with you...from my two test drives, I was surprised at the lack of torque from the V8 in the very low RPMs. Coming from a low displacement 4 banger, I kinda expected more...

About the mid pipe review, yeah...I'm reconsidering getting a mid pipe now. The same MM&FF issue reported awesome gains from a BBK throttle body coupled with a BBK intake (something like 26rwhp/32rwtq). I think I might go that route...

StangNut

I guess I wasn't specific enough and what I said could be misleading... see how easy it is.
The numbers drop off dramaticaly as the RPM's go up.
Here's the thread.
exhaust shootout in MM&FF this month

1st Stang did an analysis of the numbers, but I don't think anyone saw his post.

I attached a graph of non-muffled (same as SLP Loud Mouths) compared to stock. It shows hp & tq. The gains were 20.8 hp & 45.8 ft-lbs @ 2400 RPM, but only 5.5 hp & 9.6 ft-lbs @ 3000RPM. And it keeps going down from there. It even drops below stock hp and tq by just a little, but I'll trade that for the low end tq ANY day.

1trickpony

I love low end torque too, but how long are you going to stay under 3000 rpm in any high demand situation? Maybe passing in top gear on highway? In the quarter, you'll be over 3000 rpm in less than half a second. If I owned a truck, this would be money.

softbatch

Sounds like I am going to see about a muffler delete or get the FRPPs later on.

StangNut

I agree you don't stay in low RPM's long, but getting there is MUCH more fun now.

On a side note, all, but the JBA exhaust had the same or better numbers than the muffler delete. If you'll go to page 3, post # 53, Satin Silver 05 posted pics of the actual article and 1st Stang's spreadsheet is on page 4, post # 72.

Those show Flowmaster getting the best numbers @ 2400 RPM: 24.9 hp & 54.7 ft-lbs.

Enfynet

So it seems the best route would be headers and axleback? If a midpipe isn't gaining much? ... Or are those low end numbers midpipe numbers?

clockworks

So those numbers are real?? 20hp/40tq at below 3000 RPM?? Can you explain to me the science behind it, I don't understand at all. heck, I'd buy a $400 axle back if it gave those gains under 3000 RPM but gave NO gains at over 3000 RPM.

Also, why do these low RPM gains happen with mufflers, but not mid pipes? I have the most recent issue of MM&FF where they compare the mid pipes and this phenomenon doesn't happen.

StangNut

The numbers I linked to are just axleback kits. No mid-pipe.

If someone will post the numbers from the mid-pipe article or scan a pic of it and post it, I'll put it in a comaprison chart and make a graph.

I wouldn't "write-off" a mid-pipe until we get to see the breakdown of the numbers.

As for the science behind the numbers, I have no clue. I just know I like where the gains are.

The Boss Hog

Actually, you are correct in your skepticism. Those numbers are not "real". They are simply an artifact caused by the small differences in the manner in which the dyno operator opened the throttle. The lines are accurate only after the throttle is fully opened.

The Boss Hog

I8URVTEC

Look at the difference in the stock cats and H pipe vs the Bassani comp cats and X pipe. The Bassani's are much less restrictive. Also, didn't 5.0 Magazine do a write up like 3 months back that said Bassani cats, x-pipe and axle back plus tune was good for almost 40 hp? I am just not buying that 3-4hp garbage. :notnice: