straight pipe on 98 avenger?
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Joined: Feb 2006
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straight pipe on 98 avenger?
just wondering...i know some cars need a certain amount of backpressure from the cat/muffler, and i was thinking about having a straightpipe put on my 98 avenger sport. (2.5l v6)
has anyone done this before? how did it turn out if so?
has anyone done this before? how did it turn out if so?
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Joined: Feb 2006
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RE: straight pipe on 98 avenger?
No engines require back pressure.This is a common myth that is wrong.What engines DO require is some kind of buffering to keep reversion waves from raising he11 with the flow characteristics of an exhaust.
When an engine is operated at a single speed the exhaust is easy to design.The engine in a car operates at every engine speed from 500rpm to 8000+.It's the individual exhaust pulses that give us problems.As these pulses get kicked out of the cylinder they have momentum,this keeps them moving untill they either hit something or leave the exhaust pipe.After the exhaust valve closes there is a vacuum in the exhaust pipe caused by the slug of exhaust gas moving down the pipe.If this vacuum is released by the slug of gas leaving the pipe it starts a wave of outside air moving toward the exhaust valve.If this wave is still moving back toward the valve when it opens to let another cylinder full of burned fuel out the two slugs of gas will collide.If this happens somewhere the pressure can be absorbed,such as a resonator or muffler,that ain't so bad.If it happens in the pipe between the muffler and the header it can be a problem.
If you have an exhaust thats tuned for wide open throttle and makes the best power of any other exhaust in the world at WOT then it's my bet that the engine will run like crap everywhere else.This is where the word "backpressure"comes into play.The real word should be "dampening".This allows the pulses to be controlled so that they don't just run around and kill your HP at lower or higher levels depending on the length of head pipes and tail pipes.
When an engine is operated at a single speed the exhaust is easy to design.The engine in a car operates at every engine speed from 500rpm to 8000+.It's the individual exhaust pulses that give us problems.As these pulses get kicked out of the cylinder they have momentum,this keeps them moving untill they either hit something or leave the exhaust pipe.After the exhaust valve closes there is a vacuum in the exhaust pipe caused by the slug of exhaust gas moving down the pipe.If this vacuum is released by the slug of gas leaving the pipe it starts a wave of outside air moving toward the exhaust valve.If this wave is still moving back toward the valve when it opens to let another cylinder full of burned fuel out the two slugs of gas will collide.If this happens somewhere the pressure can be absorbed,such as a resonator or muffler,that ain't so bad.If it happens in the pipe between the muffler and the header it can be a problem.
If you have an exhaust thats tuned for wide open throttle and makes the best power of any other exhaust in the world at WOT then it's my bet that the engine will run like crap everywhere else.This is where the word "backpressure"comes into play.The real word should be "dampening".This allows the pulses to be controlled so that they don't just run around and kill your HP at lower or higher levels depending on the length of head pipes and tail pipes.
Record Breaker
Joined: May 2005
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From: Wisconsin
RE: straight pipe on 98 avenger?
I agree with chopper ^^^^^ 
It's a myth that I've fought on the internet for years...but recently gave up on...because nobody ever listens or learns [&:]
It's going to be loud as hell with just a straight pipe in there. [:'(] You'd have a hard time thinking.
You'd be better off going with a high-flow converter and a muffler that flows better than the stock one.
It's a myth that I've fought on the internet for years...but recently gave up on...because nobody ever listens or learns [&:]It's going to be loud as hell with just a straight pipe in there. [:'(] You'd have a hard time thinking.
You'd be better off going with a high-flow converter and a muffler that flows better than the stock one.
