I took my Flowmaster American Thunder 2 chamber cat-back off and replaced it with a Hooker Aero Chamber cat-back. I noticed a huge difference. I really like the way the Hooker sounds too.

 

well i have heard magna flow and dynomax and i don't like neither, especially compare to a flowmaster...and i know its much better than stock no matter what anyone says, im not that picky when it comes to gaining maybe 5 more hp but losing a great sounding muffler...thanks but no thanks, im sticking to my 80 series flowmaster.

 

Flowmaster vs Dynomax/Magnaflow (same company) HP wise is no comparison.

I've seen as well as some other guys have backed me up on this that the motor is down 20hp switching from a Dynomax to a Flowmaster.

Flowmasters sound good, but don't make power. If your after power go and get a Dynomax or Magnaflow muffler.

Bret

 

Did I say I didn't expect a huge difference? I was simply answering his question and I gave him some actual numbers.

 

I've seen as well as some other guys have backed me up on this that the motor is down 20hp switching from a Dynomax to a Flowmaster.
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well im sorry but i dont believe this statement at all, so let me get this right, switching from flowmaster to dynomax you will lose 20 hp, so let say if you switch from stock to flowmaster you might gain maybe 5-10 hp to be fair...ok so what your telling me is if i had a stock muffler and went dynomax that im gonna have approx 30 hp increase....yeah right.....i didn't know dynomax comes with built in turbo in it or something....i dont think there is any muffler out there that would give you that much gains just from the muffler itself...

 

Most F-bodies in town with other than Flowmasters sound like an old Ford truck!
My Flowmaster and gutted cat sounds like a muscle car and runs 100s times better than stock.
SLP loudmouth=Old Ford truck LOL

 

I agree with you on that one. I think it is a personality thing when choosing parts like mufflers and hedders. They are all better than stock its just what that person wants. The power comes from your motor not a muffler and if you put anything on other than stock you will make more. You cant feel 5 to 10 hp. Now if it was 25hp or more Ill say yeah but with hedders and a good muffler I can see if someone makes 30 to 40hp from those bolt ons just adding a muffler is not gonna give you those #s. So if you like Flowmaster get it. If you like Dynomax or whatever brand get. But You will still need hedder,CAI,remove cats, and programming to get the car to make power you feel. Mine already had a Flowmaster on it when I bought it so all I need is hedders and remove my cats and programming I will see what the car does then.

 

I agree there too. Flowmaster gives you the rumble when cruising and the race car sound when at WOT. Others are loud all the time and its terrible. Now dont get me wrong. Flowmasters without a cat is loud to but not like others.
Others I think compare to the FM is the Ravin series and Ive heard Spintechs on a Impala that was just down right mean. I forgot about those. Try Spintech series. YOu should love it.

 

Even if the flowmaster is restirctive (and nobody has dyno proof yet), just have a cutout. uncap it if your gonna race, good sound and (when you need it) more power than any catback/muffler.

EDIT: 700th post, Woohoo!

 

I had on mine the flowmaster sotl and it wasn't that bad, it just did not give me the sound I was looking for not a bad choice but most go with the hooker catback and I think that sounds much better then the flowmaster..

 

Check my sig. I love the combination of the Hooker shorties and FM catback. I agree it's not the best flowing exhaust setup but I probably gained 20 hp at the rearwheels and it's still legal. Here's something else to think about; how come you never hear any 5.0 guys complaining about their exhaust? Granted they're true duals but 9 mustang guys out of 10 are still runnin' flowmasters after all these years even though there are more exhaust companies out today then say 10 years ago. Just my $0.02.

 

Back when I had my Flowmaster/cutout setup, I gained ~1 MPH in the 1/8th with the cutout over Flowmaster. Now that I've got the SLP 2OTL, I'm running the same ET/MPH I was with the cutout.

 

As far as these pics/posts go, the crossflow mufflers are much different than their straight though conterparts. If you are giving examples for someone using a F-body maybe you should find a better representing picture of the mufflers used not a 50 series delta flow. In other words post the mufflers used on the car/catback in mention.

The 80 series http://www.flowmastermufflers.com/cg...ml?id=5TmLaQ9S used in dual outlet applications doesnt look all that retrictive, but I am not advocating that Flowmaster actually flows as well or better. Yes I have heard many F-bodies with FM not to mention all kinds of cars/trucks, and they do sound good. Usually the people who own them love the sound. I've never really been a fan out cut-outs but if you are scraping for every horse, open that baby up when you need it. The single outlet FM runs a 30 series muffler which looks pretty good too.http://www.flowmastermufflers.com/cg...ml?id=5TmLaQ9S

Moral of the story is if you want the best performance run duals, if not the gains of aftermarket cat-backs are all close, some a little better than others. Weigh your personal needs for performance against a want for great sound an find the best one for YOU. When in doubt cut it out. And if your still unsure just blow all your cash on GMMG like me

PS One more thing if you want a more accurate comparision then call the companies and get flow results for their crossflow applications.

Dustin

 

the people who lost 20 hp with the flowmaster are probably running more hp than the average stocker. when your dealing with 500hp engines a restrictive exhaust makes a bigger difference. with that said, i have flowmasters on mine and i love them. sounds awesome and is easy on the wallet... if you want 5-7 more hp buy borla for $700 i guess. well... slp sells an inexpensive loudmouth, but they have their own probs...

 

Nobody ever wins this arguement.

I gained 12 hp at the wheels with my Flowmaster cat-back. My buddy gained 13 with a Borla on the dyno. BTW, we found that the middle plate made the best power.