A reputable source by experience:

The local mechanic in town that always works on my car and is a good buddy of mine (even though he'* 30) claims that Dynomax are the best performing mufflers on the market. Flowmasters just make alot of noise but don't help much with performance, and Magnaflow are no better.

Yes its a mechanic talking, but hope this just allows some thought process for those who have yet to upgrade their exhaust.

i have a flowmaster 40Series not too loud good flow notice the difference Dynomax is a real goos muffler too so either one is fine

I love the name "flowmaster" and it sounds great.....But I would have to agree that is more bark than bite. It may also depend on the application.

Ty

Its instinctive that we defend that which we own. I have a MagnaFlow, and it sounds, looks and preforms great.

It was installed at a performance exhuast shop, so I wasn't about to question their product. I think any and all mechanics will endorse their products or suppliers. Is there some unbiased source that tests these mufflers?

Dynomax, Flowmaster or MagnaFlow...helps us kick *** at the end of the day.

just my .02 cents...

I'm a dynomax fan myself, but I'd really like to know how much flow difference there really is between these big three. I'd love to see an independent test using varying diameters of pipe, and varying numbers of cylinders at different rpms. I bet they're close.

I'm really not attempting to defend my owned brand. I was told this recently, the muffer was bought and installed by a different mechanic almost a year ago.

I have a flowmaster 80 series muffler on my Buick Park Avenue and I tested my horsepower before and after it was installed. It gave me 10 horsepower at the wheels.
Thats pretty good consisdering I only have a 3800 Series 1 N/A motor.

Allmachtige wow dude you got NAZZZZZZZZZZZ well come to the laughing gas club now lets all go out there and some So son how do you like it so far sweeeet stuff that little extra kick in yur arse

Well, NOW you post that!
I just sent in the $$$ for my MagnaFlow Stainless unit!

I've had the DynoMax on my '69 LeMans and never liked the sound.
After reading muffler **** for 2 or 3 weeks until my eyes bugged out, I decided on the MagnaFlow for the engineering and construction over the DynoMax for the '92 SSE application.

I'm sure the top 3 are close enough to each other that it wouldn't make much of a difference other than sound.
It'* like choosing between a Beretta, SIG, or HK pistol. All three are at the top of the game, but, you have to decide which one suits you best, fits your hand, etc. Gets kind of personal, as it should be in this case!

The construction of the MagnaFlow just appealed to me the most and I remembered that part of the DynoMax sound that 'MOANED' everytime I accelerated and then again at cruise speed...and THAT'* where I turned in the end to the MagnaFlow.
I'd much rather have a good sound and a little less power than a screamin' meemy that made little more power than the muffler with a good sound.
We'll see very soon if I made the right choice.

How much for a Dynomax on my car?