I was under the impression that having zero backpressure on a near-stock N/A engine would result in some power loss down low (hence running a 3" exhaust on a stock integra would be poor judgement) If I'm wrong let me know; so I can set these people straight:

http://honda-acura.net/forums/showth...0&pagenumber=1

Shingo


[Modified by Shingoblade-GSR, 2:54 PM 7/30/2002]

 

Nope, you never want backpressure.

That is a myth dereived from people putting on to large exhaust pipes and seeing a loss of power. They figure, "Oh, well since I have zero backpressure with my huge exhaust and have lost power down low, I must need some backpressure to have good low end"

In reality, its because of exhaust velocity and flow quantity. If the pipe is too large for how much exhaust you are generating, the pulses are not going to be big enough to maintain proper exhaust velocity.

A properly sized exhaust will have the right diamater for the pluse sizes, this will cause the pulses to line up properly and help pull each other out creating adequate velocity. A pipe that is to large, the pulses will not stay in order, and instead bounce around causing slow exit and it can even cause exhaust gases to linger.

Here are some diagram's





Plus some good articles on the subject.

http://www.team-integra.net/sections...p?ArticleID=47

http://www.team-integra.net/sections...p?ArticleID=48

http://www.team-integra.net/sections...?ArticleID=355



[Modified by StyleTEG, 1:43 AM 7/31/2002]

 

ahh..thanks a lot StyleTEG, that clears up a lot of things

Shingo

 

i know someone running a 3" exhaust on a N/A integra

backpressure=

 

Best explanation evar!!!
Couldn't have explained it better myself.

 

easy to understand..