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aight i am totally lost on backpressure. do u want it or not?? i have heard that u need it and that u dont. which is it?? also how much would u want? i ran my car for a while w/ no muffler and it seemed faster then w/ my magnaflow muffler. however at the same time i have also had just a manafold and a flex pipe with no cat, no resonator, no muffler. that set up was horrible b/c there was absolutly no power in the car. and reading all the forums i see something bout velocity. what is the best set up, reguardless if it is illegal(not saying i am goin illegal, just wondering).
 

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You don't need backpressure. You don't want backpressure. However, if you go too large on the exhaust, the exhaust gas velocity drops off and ruins the scavenging (help clearing the cylinder of burned mixture).
 

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"What all the hub-bub about exhaust backpressure? I thought I read somewhere that backpressure is irrelevant and it doesn't matter how big an exhaust pipe you use and that bigger is better.

Sam Strano ([email protected])
Not entirely correct. I agree that backpressure isn't relevant; the less the better. The hitch is that pipe sizing is very important to the flow of the system. The bigger the pipe is the less pressure is there, however if the pipe is too big for the amount of air an engine can move, you'll lose power, even though there isn't any backpressure. If you run a 3 inch system on the car, the velocity of the exhaust gases is going too slow down, because the gases have to expand to fill the pipe. And slowing down the exhaust obviously isn't what you want."

This was "borrowed" from this page:
http://www.se-r.net/faq/index.html

The main idea is to create and maintain a steady flow throughout the exhaust system.
Hope that helps.

;)
 

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Geo said:
You don't need backpressure. You don't want backpressure. However, if you go too large on the exhaust, the exhaust gas velocity drops off and ruins the scavenging (help clearing the cylinder of burned mixture).

So, how big is too big. Mine has a 4" rear/end of the muffler and a 2 1/4" midpipe... is that too big?
 

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InfinitiLvr said:



So, how big is too big. Mine has a 4" rear/end of the muffler and a 2 1/4" midpipe... is that too big?
Nahh you should be fine.
 
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