Jhoupe

Cape cod- are you happy with the magaflow x-pipe and the s300. Where did you purchase the magnaflow? Part number by chance?

Thanks

simos

There are big differencies on flow and backpressure between different designs and brands. Just in case if you look for power rather than sound...

http://www.stangnet.com/mustang-foru...master.576535/

http://www.andersonfordmotorsport.co...dia/rumble.htm

All muffler flow ratings are with a 2 1/2" offset inlet/offset outlet and measured at 28" H2O

Here goes:

3" Straight Pipe 705 CFM
2 1/2" Straight Pipe 485 CFM
Pypes Violator 453 CFM (louder than the Race-Pro)
Pypes Race-Pro 453 CFM
Magnaflow 436 CFM
SpinTech Pro Street 427 CFM
Borla 427 CFM (not stingers)
SpinTech Sportsman Street 402 CFM
SpinTech Truck/RV 391 CFM
Pypes Street-Pro 349 CFM
DynoMax Super Turbo 344 CFM
Hooker Aero Chamber 344 CFM
DynoMax Turbo 320 CFM
Flowmaster 40 series 273 CFM
Flowmaster 50 series 213 CFM (Jesus these things suck...)

For every 2.2CFM, 1 horsepower is restricted or unrestricted. That means it takes 880CFM (440x2 mufflers = 880cfm) of flow to support 400whp.
Of course that is an approximation, it's not an exact science but is a pretty close estimate.

Sound Levels

No Mufflers - 91db@Idle - 103db@2000RPM - 120db@WOT
SpinTech ProStreet - 87db@Idle - 97db@2000RPM - 116@WOT
Hooker Aerochamber - 87db@Idle - 94db@2000RPM - 114db@WOT
Flowmaster - 82db@Idle - 93db@2000RPM - 115db@WOT
Magnaflow - 82db@Idle - 91db@2000RPM - 114db@WOT

Landseer

Try PEP Boys, who stocks basic Magnaflow --- they special ordered the ones I wanted.
Beautiful part --- no freight. Bad part --- took 10 days.

For sound, I love the big tube single spintech, fed by stock cats into a Y.

17prospective buyer

Best thing to do? Get the motor subsystems back to new then take it for a drive and experience how fast a 928 should be without decades old knock sensors. Those 5L had EZK right? Can't remember correctly.

SMTCapeCod

Late response-- it is a smidge loud for me in the same rpm range where some cars drone- I don't find it to be a drone just a little more volume than I'd prefer around 2200-2600 or so. Sonorous at WOT, beefy idle. I find that my tastes lean toward more subtlety than most folks. Of course, my current middle mufflers/resonators are a bit of a mystery right now, I think other units would take additional edge off. Don't have the part number handy, but if you go to the magnaflow site you can look at the variants and pick one to meet your needs based on pipe diameter, x/no x, case size, and distance between the inlet and outlet bushings (pipes).
I went large case, with x, narrow spacing.

Have EZF, but I think knock sensors started in '87 with EZK.

ammonman

Just an FYI the car originally discussed is now on CraigsList here in Fayetteville, AR.

Mike