ezio350

Whats the scoop guys? everybody say there is no gains when replacing the axle back mufflers.... when I installed my Flowmasters, I cut the back of one of my stock ones and looked in. There was a very small opening for air to flow thru. So, compared to aftermarket mufflers, how come there is no gaih in HP? for instance Magnaflow is a straight thru muffler....

Thanks for the input.

22kart22

barely any that you can really count.

I have boomtubes and love them, but they are mostly for the muscle car sound. If i wanted power I would buy a blower

ezio350

anyone else with an opinion?

howarmat

no gains....

legendlime

Igot a big gain when I bolted on my Flowmasters...
All the dorks stopped trying to race me!!
[8D]Chris

jrm1900

The stock GT exhaust system is already well tuned so you are not making any noticeable power with a cat back. Most people change it just to get better and/or louder sound.

mustangman02232

+1 i believe it is a 2.5" manural bent tubing from the cat back as is from the factory, so you really dont need to upgrade everything unless you add boost

Stkjock

Corsa claims a 14hp bump... Livernois Motorsports has a vid on youtube showing dyno runs on a GT500 and a increase of a similar amount. I'd post the link but cant get youtube @ the office. if you use the search you'll get it 1-2-3

07SCGT

I got my magnaflows 3 days before my S/C was installed. I never dynoed it but I was able to chirp 3rd, which I was never able to do before the mufflers. Now I can chirp 4th...LOL gotta love the FI systems out there!!

07SCGT

The exception to the mandrel bend is right above the rear axle. It's very dissapointing to see that Ford kinked the hell out of it in order to clear the axle, at least it's this way on the 07's.