I was wondering. I have a Thermal R&D 2 1/4" mandrel bent B-pipe, with a Universal no-name muffler welded to it, on my 2000 Civic Si. I was thinking of installing my factory axle back exhaust onto the aftermarket B-pipe to quiet down my exhaust tone(I have a test pipe) and to give the rear of my car a cleaner OEM look. Will I lose alot of hp/tq if any at all? Is the factory muffler so restrictive that it will slow me down alot or are most of my power gains coming from the b-pipe and not the muffler?

 

ttt

 

Yes, you will lose the horsepower and torque you "bought" with the aftermarket muffler.

If you ever opened a stock muffler you would see that the exhaust flow actually changes from going back to forward and back twice.......talk about a bottle neck.

If you are trying to quiet the exhaust add a huge resonator in the B-pipe. For the muffler sorry.....

Or if you don't mind spending money get the Apexi WS cat-back. It looks clean and is quiet. (480 dollars)

I have some unknown cat-back on my EX and it was a little too loud......added in a 24" resonator instead of the 18" and the sound improved quite a bit.

 

I had a Greddy Power Extreme on my GSR, with the resonator cut out...it was hella loud, and I felt I couldnt stand it anymore. I bought an ITR rear section, and it did bolt right up (much to my surprise)...also, I really didnt notice any performance loss with the stock ITR rear section...it actually felt quicker to me, plus the noise it non-existant when driving normal...I say go for it.