[9Cobra6]

The most popular for the stang gang is the 2 chamber Flowmaster, but its one of the lowest flow rates. To most, the SOUND is most important!! When Hp is the quest! Why???



Muffler Flow Comparison Chart
Shown below are competitive mufflers versus DynoMax Ultra-Flo SS and Race Magnum Welded models. For Powertech Index cold-flow testing, the pressure drop across the muffler is held at 20.3" H2O and the flow rate (scfm) is recorded.

MODEL (Flow Rate- @ 20.3" H2O) Muffler Inlet Size


+ Edelbrock 5501 492 scfm 2.25"
$ Flowmaster 42440 483 scfm 2.25"
Race Magnum Welded 17216 711 scfm 2.25"

+ Edelbrock 5511 579 scfm 2.50"
$ Flowmaster 42540 352 scfm 2.50"
Ultra-Flo SS 17263 1133 scfm 2.50"
Race Magnum Welded 17218 1000 scfm 2.50"
# Borla 40600 836 scfm 2.50"

+ Edelbrock 5505 708 scfm 3.00"
$ Flowmaster 43040 392 scfm 3.00"
Ultra-Flo SS 17296 2200 scfm 3.00"
Race Magnum Welded 17220 2200 scfm 3.00"
# Borla 40450 1400 scfm 3.00"
# Borla 40575 1100 scfm 3.00"

@ Edelbrock 5535 562 scfm 3.50"
$ Flowmaster 435409 576 scfm 3.50"
Ultra-Flo SS 17268 2200 scfm 3.50"
Race Magnum Welded 17224 2200 scfm 3.50"
# Borla 40615 854 scfm 3.50"

@ Edelbrock 5537 1400 scfm 4.00"
* Flowmaster 54040-10 634 scfm 4.00"
Race Magnum Welded 17225 2600 scfm 4.00"
# Borla 40741 1450 scfm 4.00"

+ Edelbrock General Application Series
@ Edelbrock Victor Series Race
$ Flowmaster 40 Series ( 2 Chamber)
* Flowmaster Delta Force Race Series
# Borla XR-1 Racing Series (Round or Oval)

[milw96cobra]

Just goes to show you how much better those Dynomax Ultra-Flo's are.

[Vortex]

they were once a really good flowing/sounding muffler... other companies have come out with better designs.. they sound like stock mustangs should sound in my opinion...