[RTH Jimmy]

I just installed the Flowmaster Axle Back American thunder on 4/15. I do not like them; similar sounding to stock just louder. I was looking for the classic Flowmaster sound but was disappointed. My last two mustangs (88'&93') had Flowmasters but they were an aluminum color, does anyone what these mufflers are called? They were on the cars when I bought them, I know for sure that it not american thunder!

Also, has anyone had a pair of mufflers welded in place of the stocks?

[Adrenal]

Originally Posted by RTH Jimmy

I just installed the Flowmaster Axle Back American thunder on 4/15. I do not like them; similar sounding to stock just louder. I was looking for the classic Flowmaster sound but was disappointed. My last two mustangs (88'&93') had Flowmasters but they were an aluminum color, does anyone what these mufflers are called? They were on the cars when I bought them, I know for sure that it not american thunder!

Also, has anyone had a pair of mufflers welded in place of the stocks?

I think you are looking for the "original flow" Series 40's. They are much louder than the Delta flow 40's.

[R3dF1r3]

I really don't see anybody getting better RWHP/ RWTQ gains unless they delete the stock "H" pipe for an "X" pipe, improve the stock cats to hi-flo, add headers (shorties or long tubes) and mod the axle backs.
Just doing the axle backs will give you in some cases a different tone but, for that cost and zero gains the stock is still a good bet. Lol, unless one is just looking for a chrome bit out the back.
Once I perform my exhaust mod, I will post dynos.

[mypony]

Here is a response to a question that I posed to Corsa who makes an axle back system that sounds very nice. Their dyno'ed results show 13 Hp/9 Torque gains.
http://www.corsaperf.com/mustang.htm

Thank you for your inquiry. Our Mustang GT system has been available
for over three months and the comments and results have been very
positive. As with any performance product, there will always be
difference of opinions and results.

At CORSA Performance we pride ourselves on our technology and results.
Our performance results are done by outside, reputable companies using
the latest technology. As a manufacturer of high end exhaust, we take
pride in our performance and information given so the end consumer can
make an educated decision.

All information was obtained with a stock Mustang GT. The only thing
done to the vehicle was to take off the factory exhaust and put our
system on. Nothing else was tuned, modified or adjusted.

Flow gain was 452.1cfm vs. 322cfm on the factory system. If you
subscribe to the fact that the more you allow the vehicle to breath
(like a good runner or race horse)the better overall performance you
will have.

With this concept in mind, we will stand behind our average numbers and
deliver a sound that is "Awesome at wide open throttle, Whisper Quiet at
Cruise". We eliminate that interior resonance and drone that you may be
familiar with. The old "glass pack" sound is gone. You will enjoy the
CORSA sound from start to finish.

[tksuther]

Originally Posted by mypony

Here is a response to a question that I posed to Corsa who makes an axle back system that sounds very nice. Their dyno'ed results show 13 Hp/9 Torque gains.
http://www.corsaperf.com/mustang.htm

Thank you for your inquiry. Our Mustang GT system has been available
for over three months and the comments and results have been very
positive. As with any performance product, there will always be
difference of opinions and results.

At CORSA Performance we pride ourselves on our technology and results.
Our performance results are done by outside, reputable companies using
the latest technology. As a manufacturer of high end exhaust, we take
pride in our performance and information given so the end consumer can
make an educated decision.

All information was obtained with a stock Mustang GT. The only thing
done to the vehicle was to take off the factory exhaust and put our
system on. Nothing else was tuned, modified or adjusted.

Flow gain was 452.1cfm vs. 322cfm on the factory system. If you
subscribe to the fact that the more you allow the vehicle to breath
(like a good runner or race horse)the better overall performance you
will have.

With this concept in mind, we will stand behind our average numbers and
deliver a sound that is "Awesome at wide open throttle, Whisper Quiet at
Cruise". We eliminate that interior resonance and drone that you may be
familiar with. The old "glass pack" sound is gone. You will enjoy the
CORSA sound from start to finish.

Wow. $695.00 is big bucks for mufflers. From my own experience with tuning and reading several threads on other people's experience with the difference in gains after various mods on other '05s, I'd be surprised if 13/9 gains are realized even as an average. They do look nice and assuming they sound incredible (hard to tell from a recording), I personally think it would be hard to justify for the price. Has anyone bought and installed these and gone to the dyno to check the gains?

[R3dF1r3]

I am sure the dyno tests are accurate. Corsa is indeed a very fine auto component, my freind has them in his 2004 Corvette. I was thinking on Corsa myself however, they only offer the axle back components. It still won't improve the potential stock "H" pipe to "X" pipe gain nor potential higher flow cats.

For a bit more you can address the entire exhaust from cats back to tips with Bassani or Borla and pick up even more gains.

[ChestyP79]

Does anyone have clips of the MACs, Flowmasters, and SLP Powerflos?

[rakkassan34]

I have been scouring the internet for these and found most in other forums. I don't remember any info on the cars except which axleback exaust they used so no questions about the cars please. I was looking for something a little louder,deeper,meaner without sacrificing the driveability of the vehicle. I settled on the MAC's now I just have to wait for them to come in.

Hope this helps

ok I tried to upload a zip file of the exaust mpeg's I have but I guess it's too big. If you email me I'll send it.

[Adrenal]

Originally Posted by ChestyP79

Does anyone have clips of the MACs, Flowmasters, and SLP Powerflos?

Here's one for the new Flowmaster Kit.

http://www.flowmastermufflers.com/cg...ml?id=Dp2E9eZy

[kj_cinci]

I think I'll be selling my MAC axlebacks. The sound is awesome (idle, low RPMs and all the way to the red line, awesome!) Low end TQ increased as well (especially in combo with the X-pipe)! I just can't get used to the drone around 2000 RPM and at high gear slow acceleration. I love the car and am looking fwd to my commute of 35 min's each way but it's all on highway and just at the wrong speeds and hilly terain with looong uphills (and downhills where it sounds awesome! )

Am putting on stock tomali and will see how they go with the X-pipe...

Le'me know if you might be interested in a pair of MAC's with about 400 miles on them.

[Marxxus]

I bought the JBA axle backs and I could not be happier. Great sound at idle, not exactly louder, but more throat sound. At take off from a stop fantastic sounding (loud and meaty) and through 3rd very beefy. Once I am at highway cruising speed, very hard to tell the difference from the stock system.

JBA's were 311.50. Cannot beat the price for the sound.

[kj_cinci]

Well, I'm back to stock, dang does it sound boring. I also lost that low end TQ... Now she's not too happy to go at 2nd from an almost stand still... what to do, what to do...

I know I'll take a loss on these and am not going to get an new pair until I'm sure there is NO drone at (my) commute/cruise! Maybe the JBAs or Bassanis? Corsas are nice but way too pricy... time will tell...