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i just read the last post about the 2.5 vs. 2.25 diam. exhaust system setup. why does the myth about "back pressure" continue to thrive on this board? back pressure isn't the overall determining factor in your torque and horsepower. it's actually a matter of e.g.v. (exhaust gas velocity). any naturally aspirated engine up to 2.0 liters in displacement needs nothing more than 2 inch MANDREL BENT exhaust. if it is a crush bent exhaust system, you shouldn't even concern yourself with true performance gains. if you have a 2.5" system with 2" bends, it is NOT the same as a mandrel bent 2" system. the exhaust velocity and pulse actually draws the exhaust gases from the engine instead of the engine itself actually having to push all the exhaust gas out (as is the case with crush bent). i'm not looking to bash anyone here, and i hope that this is all taken as a simple statement on my part. if i stepped on any toes, allow me to appologize right now, but all that i am trying to do is help out our hyundai community as a whole. thank you so much guys for your time spent reading this.


<hr noshade width=60% size=1 align=left>H.A.T.E.
hyundai accent tuner evolution
 

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Discussion Starter · #2 ·
p.s. i didn't want to sound like a total geek and go into any great detail, but if anyone would like to continue this discussion with me, you are more than welcome to e-mail me.

sorry for replying to my own post.



<hr width=60% noshade size=1 align=left>H.A.T.E.
hyundai accent tuner evolution
 

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Well said. Well said indeed <img src=/images/forums/snitz/thumbup.gif width=25 height=18 border=0>.

Isn't thermodynamics a bitch? <img src=/images/forums/snitz/laugh.gif width=15 height=31 border=0>


<hr width=60% noshade size=1 align=left>"Hey, if my prize is your foot up my arse... its still a prize.... " - <b>WhoopOi</b>

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so then, why do even the pros that i talk to suggest the same? 2.25" is the max, need to hold some back pressure...what the hell is back pressure anyways?


<hr width=60% noshade size=1 align=left>"Even in death we live!"
 

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well i cant really put the description of backpressure into good words, but ido know that you need it because it will provide cushion for your valves. For example: if you are runnign straight exhaust the exhaust will flow out of your pipes freely and at will. Your valves will slap against your heads very hard casueing small damages on the surfaces leading to leaks and what not. theres more rasons for backpressure but i dont know them all..especially not at this hour....hope i helped


<hr width=60% noshade size=1 align=left>I bleed nitrous and sweat gasoline......is that bad?
 

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<img src=/images/forums/snitz/thumbup.gif width=25 height=18 border=0>Okie thats not the only thing backpressure does for you, especially in a forced induction engine. As your valves reach their overlap perigee(phase angle) your turbo is still spooling(freewheeling) and this will practically blast the incoming cold air charge through the inlet valves and out the exhaust valves!What backpressure does is it provides a static gas "dam" made of hot,expanded gases that blocks to a certain degree the exodus of the incoming charge and mantains your compression stroke consisting of fresh gases.

Thats why most ricers have to learn that bigger isnt necessarily better,and why they continue to bet their RSX butts kicked by the Sylvia Club.


<hr width=60% noshade size=1 align=left>Power without the skill to control it is a dangerous thing...
 
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