Nickn20

your car isnt making as much hp as his, how can you be so sure?

what i would like to know is was a flowmaster dual 3 inch to 4 inch collector the restriction or the muffer, hopefully its the muffler. I got a replacement for that on my rig

http://www.magnaflow.com/02product/universal/round.htm

hehe bottom of the page diesel muffler 4 inch in and out

Joe Kizzire

A little over a year ago I was competing in an NMCA event in Atlanta with a complete Mufflex 4 inch system (spintech muffler). I did nothing but remove the muffler from the over the axel pipe and the car went from 12.15's @ 112mph to 11.80's @ 118mph and these two runs were within one hour of each other. I never put it back on the car... It went to the junk pile.

Bowtieman4life

iTrader: (1)

VIctor you are a bonafied knuckle head. Because you already have a restriction by using cats, uncapping your exhaust will not make as great a difference. If you didn't have the restriction from the cats, I bet you would notice larger gains.

SouthFL.02.SS

This thread was started involving a Spintech single in/ 4" single out. Correct?

I purchased the Spintech 3" In/ Dual 3" Out after specifically asking the tech/sales rep at Spintech, which flowed better; single or dual? He recommended the Dual Outlet muffler.

I would like apple to apple comparos before a manufacturer's name and reputation is slung through the mud. Sure, the Dyno example listed above is convincing when talking single/single, but anyone else have some hard figures when dealing w/ single/dual? Most other cat-back systems are single/dual.

BurnOut

iTrader: (1)

SouthFL.02.SS- that's right; my system was single 4" in/out. To be fair, I don't know that going to a dual outlet Spintech would make a difference in my situation. I just felt that the power loss through such a large muffler was excessive, and that's why I posted up.

However, I have a friend with a 3000GT VR4 that had a custom Spintech made (single 3.5" in, dual 2.5" out, cross-flow style) and integrated into his hand-built exhaust. He was running consistent 12.0's through the Spintech, and with no other changes at all, he was able to run consistent 11.7's after dropping the muffler right where the exhaust went into it (read: no bends, etc... were eliminated). The quicker times were attained on the same day, at the same track, only ~90 minutes apart. I fully realize that a 3000GT is not an F-body, but a 3/10 drop in ET indicates a fairly significant power gain just by ditching the muffler.

Jason99T/A

iTrader: (21)

My 3.5" Mufflex listed above was the single in/dual out.

SouthFL.02.SS

OK. Thanks. Time for a cut-out!

smslyguy

I have a 3" y pipe to a 4" that goes to a spintech muffler. From there I have a dual 3" outlet. What I was finding on catback exhaust was they were only offering a 3" y to a 3" collector... Not rocket science people, u still end up with a 3" exhaust system.. as to why I went with the 4" catback exhaust. Much less restricive.