Aftermarket muffler CFM flow comparisons
 

I stumbled upon this the other day. Anyone looking to compare (general) flow characteristics of various high-performance mufflers might be interested.

Of course, you'll need Adobe Acrobat Reader to view:

http://www.exhaustsoundclips.com/cfm.pdf


[Modified by twotone82, 3:26 AM 10/8/2002]

Re: Aftermarket muffler CFM flow comparisons (twotone82)
 

That is one of the most useful posts I have seen here in a while! :cheers:

Look at the harsh numbers for OEM. :nonod:

Re: Aftermarket muffler CFM flow comparisons (SuperFast80)
 

can you post the results in your thread

Re: Aftermarket muffler CFM flow comparisons
 

Alwyn678:

I hope this lines-up correctly (well sorta lines-up):

OEM..................................... ........................................ ...225
Gibson SuperFlow 788200.................................. ............311
TTS Bullet Cat Converter............................... ..................324
Flowmaster 40 series 42540................................... .......352
Flowmaster 50 Series.................................. ...................362
Flowmaster 40 series 43040................................... .......392
Dynomax Super Turbo................................... .................410
Flowmaster 62631................................... .......................435
Carsound Cat Converter............................... ..................436
FLP Cat Converter............................... ............................440
Edelbrock Victor 5535.................................... ..................562
Flowmaster 40 series 435409.................................. ........576
Edelbrock RPM series 5511.................................... ..........579
Flowmaster Delta Force Racing 54040-10........................634
Edelbrock 304 series 5560.................................... ...........640
Edelbrock Gen App 5505.................................... ..............708
Dynomax Race Magnum Welded 17216...........................711
Borla XR-1 40600................................... ..........................836
Borla XR-1 40615................................... ..........................854
Dynomax UltraFlow SS 17263................................... .......1000
Dynomax Race Magnum Welded 17218...........................1000
Borla XR-1 40575................................... ..........................1100
Dynomax UltraFlow............................... ...........................1133
Edelbrock Victor 5537.................................... ..................1400
Borla XR-1 40450................................... ..........................1400
Borla XR-1 40741................................... ..........................1450
Dynomax UltraFlow SS 17296, 17268..............................2200
Dynomax Race Magnum Welded 17220, 17224...............2200
Dynomax Race Magnum Welded 17225...........................2600



[Modified by twotone82, 2:09 AM 10/9/2002]

Re: Aftermarket muffler CFM flow comparisons (Alwyn678)
 

The Dynomax Race Magnum's flow is incredible. Of course ya don't bolt them onto your daily driver. :crazy:


[Modified by twotone82, 2:21 AM 10/9/2002]

Re: Aftermarket muffler CFM flow comparisons (twotone82)
 

Very interesting... but what are our engines capable of producing? Can they produce 700 cubic feet per minute of exhaust gas to take advantage of a muffler that is rated at 700 cfm? That chart makes it very tempting to upgrade from Flowmaster 50s that "only" flow 362 CFM. But, if I put on a pair of Edelbrock Gen App 5505 that are rated at 708 CFM would I be flowing twice the exhaust gas? Somehow, I doubt it, but wondering what % improvement I might see. MJ

Re: Aftermarket muffler CFM flow comparisons (MNJack)
 

If you use the carb cfm intake formulas, must of us would need about 600 to 650 cfm at WOT.

cfm=cubic inches x max rpm x V.E. / 3456
(use .9 for VE)

Re: Aftermarket muffler CFM flow comparisons (AlwaysWave)
 

The formula for required exhaust flow is: horsepower times 2.2. Pretty simple eh?

So if your car makes 400 hp, you will need a total of 880 cfm muffler capacity for an unrestrictive exhaust system. So for dual exhaust, you would need mufflers that flow 440 cfm.

For reference, a 2.5 inch diameter pipe flows ~500 cfm. Adding non-mandrel bends will lessen that amount.

Re: Aftermarket muffler CFM flow comparisons (twotone82)
 

The chart is interesting; BUT, it doesn't say anything about the silencing effectiveness of each of them. I could bolt on a 4" open pipe with a piece of chewing gum in it and call it a muffler too.

Chuck

Re: Aftermarket muffler CFM flow comparisons (Chuck Harmon)
 

I thought that's what you did...

...or are your pipes only 3"? :confused:

-Steve

*edit* I really do love the Dynomax Ultraflows, myself. Sound great, AWESOME flow. My Super Turbos are decent, but not spectacular.


[Modified by Pacin'California, 7:32 PM 10/8/2002]

Re: Aftermarket muffler CFM flow comparisons (Pacin'California)
 

Now this guy's got some flow. That powerful in-line 4 has to breathe!

:U

http://www.redgatesystems.com/riceburner.jpg

Re: Aftermarket muffler CFM flow comparisons (twotone82)
 

Where is this info coming from? I doubt that the Flowmaster 40's flow less than the flowmaster 50's since the 40's are 2 chamber and the 50's 3 chamber,and both seem incredibly low to boot. :confused: Something tells me it is a Dynomax generated report.


[Modified by Fevre, 8:22 AM 10/9/2002]

Re: Aftermarket muffler CFM flow comparisons (Fevre)
 

The race magnums are not for street use at all, SuperFast80 has one of the Race Magnums, not the highest flowing they offer and they are very very loud as he will tell youbut they do sound very mean. Not much in them to divert any air flow.


[Modified by gdh, 9:39 AM 10/9/2002]

Re: Aftermarket muffler CFM flow comparisons (Fevre)
 

[. :confused: Something tells me it is a Dynomax generated report.


[Modified by Fevre, 8:22 AM 10/9/2002][/QUOTE]


no Question there :yesnod:

Re: Aftermarket muffler CFM flow comparisons (twotone82)
 

I would like to know the basis on the report. What did they flow test them in water? Did they do it in 25 or 28 inches? Hooker mufflers were not even included. This is the flow data for them according to Holley. http://www.holley.com/HiOctn/ProdLin...HHM/fAFAC.html
If you go back in the link you can see the other comparisons like sound, torque, and hp claims.

Mark B.

Re: Aftermarket muffler CFM flow comparisons (twotone82)
 

My Borla's had a higher rating than the Flowmasters 40's C:cool::cool:L :cheers:

Re: Aftermarket muffler CFM flow comparisons (twotone82)
 

Leave it to a ricer.. :U

Re: Aftermarket muffler CFM flow comparisons (Fevre)
 

I have no idea where the info came from except http://www.exhaustsoundclips.com. I doubt they are definitive results. I just found them interesting. The site said the results are as accurate as their sources. ;)