Results based on 5.0 Mustang Magazine December 2002 issue (page 55). Test car is a ’90 Coupe with 370 HP and 11 second potential. A number of 66 pulls were made to compile this information. Where does your muffler stack up?

The results in HP order:

1.Flowtech Warlock (open) 374.2 hp/ 333.1 tq
2.Bassani Real Street 373.7 hp/ 333.8 tq
3.Hooker Maxflow 373.5 hp/ 333 tq
4.Borla XS 373.3 hp/ 332.6 tq
5.Magnaflow 372.8 / 332.5 tq
6.MAC 372.3 hp / 331.5 tq
7.Flowtech Afterburner 372.3 hp/ 330.1 tq
8.Hooker Aerochamber 372.1 hp/ 330.4 tq
9.Bassani 372 hp/ 333.5 tq
10.Spintech 371.6 hp/ 332.2 tq
11.Edelbrock Performer RPM 370.9 hp / 331.3 tq
12.Borla XR1 370 hp/ 334 tq
13.Flowtech Terminator 369.5 hp / 331.3 tq
14.Dynomax Ultra Flo 369.4 / 333.2 tq
15.Flowmaster 369.4 hp / 331.8 tq
16.Flowtech Warlock 366.3 hp / 325.3 tq
17.No muffs 365.2 hp / 330.1 tq

I found this at a truck site so don't flame me for the mustang info. The thread is here http://www.truckworld.com/cgi-bin/ub...=1;t=007901;p=

Look how low the ultra flows are. I'm going with a tru dual setup and I'm thinking flowtech afterburners or hooker aerochambers.

 

Good info, but you can't apply it to these cars.

 

You can if you are going with a tru dual setup or even if you are going with a single outlet exhaust.

 

Not with the info listed. 2.5", 3", what? One companies 2.5" may flow better, but the other's 3" may flow better. OR the same muffler can make better/worse power on a different engine then what's there. Like I said, you can't really directly compare, though its good information

 

to tell you the truth, i'm not sure it makes that big of a difference
all of those are in the same range of each other really
unless you're really concerned about getting every last ounce of power out, just pick the one that has the sound you want

just my .02

 

there's more hp with a muffler vs. no muffler? (look at the very bottom of the list)

 

that's probably due to lack of back pressure, since it's true duals

 

They didn't retune for open exhaust is why it shows less with open exhaust.

 

Actually, yes.....

A muffler, when designed properly, acts similar to a header collector as an expansion chamber creating a low pressure area that can be used to draw out exhaust gasses.


-Dave C. '97 Z28