Flowmaster 's40 have a raspy sound because they have crappy internal structure. H-pipes help reduce the rasp, as do larger pipes, but it's still going to be there. They also tend to drone in the cabin, are absurdly loud, and have poor flow characteristics.

I prefer Magnaflow, Dynamax, or Borla, for standard mufflers. I have Flowmaster Hushpower II's, which are awesome, but are also very expensive.

 

I know this is kinda a hyjack, but what about the Cherry Bomb Vortex? I saw an old episode of Gearz where they flow tested a Vortex (72% flow) vs a competitor that looked like a flowmaster (45%). Does anyone run the Cherry Bomb Vertex?

Episode:
http://www.gearztv.com/showdetails.php?episode=10

 

i have flowmaster 44s and while i absolutely LOVE the sound they make while accelerating, the inside drone while cruising at low speeds is quite obnoxious. i would be interested in replacing them if i could find a muffler that had a good sound. im kinda curious about the purple hornies...

 

I don't think that Flowmaster is really that raspy. If you want to know what raspy is then listen to glasspacks.

 

That does look like a Flow 40 on Gearz. I wonder if it is or not.

I really can't believe that their muffler really works that much better though. What if they be the Flow on backwards. LOL...

Does anyone know what type of muffler that really was?

I wish those TV shows would do actual tests and not be afraid to tell the truth about products even if its bad. All they really seem to do these days is promote their advertisers products. The tech parts are still interesting, but the products part, I don't really take it too seriously.

 

Glasspacks are definitely more raspy, but 40's have quite a bit of rasp to them, especially when compared to Dynomax, Magnaflow, or Borla. My Hushpower II's have basically no rasp.

 

seems there's even a huge difference in which 40s you get:
http://www.exhaustsoundclips.com/cfm.pdf

 

I guess so. I don't like Dynomax. The ones I have heard offer virtuall no sound. The Magnaflow just doesn't sound nearly as good, altough it is a good way to go if you want lower volume and a good tone.

 

Thats interesting, but wouldn't 2 300-400 cfm mufflers be adequate for most cars running 500-750 cfm carbs? Thats my thought.

If the regular 40 flows enough for big block setups then on our Mustangs I don't think the ones that flow more cfm would really make any difference in performance.

Also, I wonder about some of these charts. Are they really from an independant source or not.

 

We went with Magnaflows and love them. Deep, throaty sound but really open up when under a load. There is some noise inside, but we have no insulation under the carpet right now. They did get a little louder when we went to the new intake and 4bbl. $89 each, installed.
Here's a clip before the intake swap.
http://www.youtube.com/watch?v=bmGIv12oG6k