I just recently just for a trial run took my exhaust off right after the cat. and it game my car the sound that i wanted but at the same time while taking it for a test drive i noticed a loss in low end torque? launching at 7500rpm and the tires barely loosing traction (with dsc off) and was jsut wondering if anyone knew why i had such a loss in power and if there is any way around other than forced induction? and on the trial run i barely beat a stock civic si! so if anyone could help me out i would be most thankful

 

Internal combustion engines require a certain amount of back pressure in order to maximize power output. By removing most of the exhaust system, you essentially eliminated most of the back pressure. You can install a straight-through exhaust system that will provide the required back pressure, but that requires tuning the piping which is akin to a black art.

 

Actually no. Backpressure is necessary ONLY in small displacement engines, since the engine produces very little torque in low RPM. In those engines, a *certain* amount of backpressure is required, in order to "keep" the intake charge inside the chambers. Even in these reciprocal engines, backpressure becomes a problem at high RPMs.

Rotaries are a totally different story though. The 13B *might* require some minimum backpressure, in order to produce decent torque in low RPMs, due of course to the peripheral position of the ports and the resulting overlap. The Renesis, which its side ports, has absolutely no need for backpressure. Overlap is not an issue, so all backpressure does is hinder the Renesis' operation

As for the initial poster:
1) Two years and two posts ? Yippy....
2) Two posts and what ? The same thing in two different threads
3) If you cannot beat Civics Si with your RX8, then you obviously have bigger problems than your exhaust.....

 

group therapy..

beers

 

High air stream velocity is not the same as backpressure, no backpressure is good for any engine performance.