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will i have enough back pressure

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Old Sep 1, 2008 | 11:17 PM
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Default will i have enough back pressure

like the title says .. if i place 2 cut outs on my y pipe?
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Old Sep 1, 2008 | 11:37 PM
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you don't want back pressure, if you do, don't put the cutouts on and smash a couple of potatoes in your tail pipes.

The whole point of the free flowing exhaust modifications is to eliminate back pressure.
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Old Sep 2, 2008 | 12:33 AM
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and i would run better w/o back pressure
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Old Sep 2, 2008 | 08:56 AM
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what he said,you dont want backpressure.Where did you get the idea that you wanted backpressure.You want it free flowing with good velocity.
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Old Sep 2, 2008 | 10:17 AM
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backpressure is an off concept, the "backpressure" some mechanics talk about references for EGR systems, and even with 1 3/4 longtubes, there's still PLENTY of normal flowing pressure to power that. Ever try to seal an exhaust leak at a collector? Pain in the *** if you aren't welding it. How's that for exhaust pressure?
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Old Sep 2, 2008 | 10:29 AM
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I always thought that true duals off the mani's was to free flowing? Because that's my setup right now no cats either. I'm probabaly loosing something down low but gained top end I'd much rather have tq down low anyways. Plus it really ***** with your ltft's too
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Old Sep 2, 2008 | 11:18 AM
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yeah you dont need any,so you will be fine..i think the only thing backpressure is important for is turbo cars...
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Old Sep 2, 2008 | 11:37 AM
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Originally Posted by 00cls1camaross
you don't want back pressure, if you do, don't put the cutouts on and smash a couple of potatoes in your tail pipes.
.
lol

"I aint fallin for no bannana in my tail pipe!"
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Old Sep 2, 2008 | 11:55 AM
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LOL beverly hills cop :OD
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Old Sep 2, 2008 | 12:33 PM
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Originally Posted by johnLs1camaro
yeah you dont need any,so you will be fine..i think the only thing backpressure is important for is turbo cars...
where you would want EVEN LESS!?!?!?!?!?!?????
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Old Sep 2, 2008 | 12:54 PM
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yeah with no exhaust pressure, that turbo will work great. if you want some real answers grab a book. no offense to the guys that know what there talking about about, but pressure in the exhaust is a neccesary evil. thats why there are different exhaust systems out there. some work better than others some are bigger in diameter. tuned length headers for instance, somke make better torque some make horsepower. i am no scientist but i have been playing with cars for a long time, i like to think i have gained some knowledge.
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Old Sep 2, 2008 | 04:40 PM
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Yea, I've been reading about exhaust and back pressure and what not as well. It is not all about back pressure and flow...but how the flow works well with removing the exhaust quickly. You want exhaust to exit as quick as possible. 5" diesel exhaust on our cars is bad, because it is just too slow moving out of the pipes. There is a write up somewhere saying what size pipes are good for how much power. Headers fall under the same concept; slightly smaller pipes, and good merg collecters, to help increase scavenging and flow. Sure, 1 7/8 or 2" exhaust is free flowing, but given a certain application, it is useless. Search around here, and even decent import forums (good write up on this subject here http://www.hondacivicforum.com/forum...ead.php?t=3064), and on our site go in depth about exhaust, back pressure, scavengin, ect.
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Old Sep 2, 2008 | 06:32 PM
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It is not about back pressure, you do not want back pressure at all! It is about exhaust gas pulses and exhaust gas expansion rate. If the exhaust gases expand to fast in a large chamber, the exhaust gas will cool down faster and the scavenging affect is reduced. Scavenging is what makes or breaks an exhaust flow, not back pressure.
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Old Sep 2, 2008 | 07:40 PM
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Originally Posted by 12secSS
It is not about back pressure, you do not want back pressure at all! It is about exhaust gas pulses and exhaust gas expansion rate. If the exhaust gases expand to fast in a large chamber, the exhaust gas will cool down faster and the scavenging affect is reduced. Scavenging is what makes or breaks an exhaust flow, not back pressure.
This is exactly right. This forum is so much better than import forums.
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Old Sep 2, 2008 | 08:58 PM
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Originally Posted by jam01
yeah with no exhaust pressure, that turbo will work great. if you want some real answers grab a book. no offense to the guys that know what there talking about about, but pressure in the exhaust is a neccesary evil. thats why there are different exhaust systems out there. some work better than others some are bigger in diameter. tuned length headers for instance, somke make better torque some make horsepower. i am no scientist but i have been playing with cars for a long time, i like to think i have gained some knowledge.
I'm sorry, but if you think a turbo system needs a lot of backpressure you're wrong. Why do you think every 4 cylinder turbo car exhaust system out there is 3 inch piping? Its not just backpressure, its a combination of exhaust processes.
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Old Sep 3, 2008 | 08:48 AM
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lol thats preety funny "this forum is soo much better than import forums" but now i came up on another problem .. some shops dont want to work on my 3'' exhaust and put cut outs on my y pipe because they were saying somthign about the exhaust not heating up enough to evaporate the moisture in the exhaust and would cause it to eventually rust out.. he said this was due to having too large of an exhuast . he said i should ahve went w/ a 2.5 inch exhaust not a three inch.... i think the damn thign gets really hot. but im wondering if any one has heard of this???.. but also how hard is it to put cut outs on the y pipe .. i kinda wanted to do it myself becuase they said it would be aroudn teh 100 dollar range to cut out a section to weld in a new one...
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Old Sep 3, 2008 | 09:03 AM
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exhaust shops most of them are idiots to be honest. and they have to obey EPA standards and etc.

a cutout is for race, its not something you have open on the street
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Old Sep 3, 2008 | 09:17 AM
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wow i didnt know every 4cyl turbo car had 3 in pipng. what exactly is exhaust processes, some kind of pressure? what exactly spins the turbine in the turbo- oh yeah those little japanese kids. is that why there called ricers? yes i know we want freeflowing exhaust but there will always be some sort of pressure.
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Old Sep 3, 2008 | 09:20 AM
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for sure... thats what i thought too . that every car needs some sort of backpressure
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Old Sep 3, 2008 | 09:27 AM
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Originally Posted by ls1motorsports
for sure... thats what i thought too . that every car needs some sort of backpressure
its not back pressure. its exhaust scavalaning[sp]. oversized exhaust will slow the air down to point youll lose lowend. to small of exhaust will restrict exhaust up top creating backpressure and causing harm to motor.

this is why right size tubing is cridical... stepped headers is good example of this. they help aid in torque by having smaller tubes intially then by stepping up they help the gases escape creating more topend
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