Poor peformance after mods, help
08-27-2004, 03:39 PM
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Originally Posted by Foghorn
Originally Posted by DrJay
No engine works better with backpressure. Read that twice if you need to. Backpressure only makes the engine work harder to get the exhaust out.
Originally Posted by DrJay
What you're experiencing when you make your exhaust too large is a combination of two things. One is that (as most of you may know) the exhaust from one cylinder actually pulls exhaust from the next.
Since most of us drive our cars under a variety of load conditions, it'* neither correct to say you need a lot of backpressure nor to say backpressure is your enemy. If you want only to maximise the performance of your car for one driving conditon, like WOT, then you could optimise the exhaust for that condition only whereby you'd want little backpressure. On the other hand, if you rarely went WOT and wanted better drivability and throttle response around town, then you'll need backpressure but you'll suffer at the track.
Like many things, backpressure is a comprise condition in response to a variety of demands we put on the engine to respond under loads.
Hope this makes sense...
Cheers,
Blah ok, well I'm saving my typing fingers for the other thread ("Give your supercharger what it wants" : good debate so far, join in) so I'll make a quick comment and suggest some 'good reading' for the time being.
I'd really suggest people go to google.com type in "Backpressure myth" and see what they come up with. Here is an exampleto get you started:
http://www.uucmotorwerks.com/html_pr...torquemyth.htm
09-10-2004, 12:25 AM
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LOL...anyways back on topic...When I got my 2.5inch cat back on my 95 SSEi I immediately noticed a lot less off the line punch but at the time the only other mod I had was a K&N cone stuck on the end of my intake mani...(bad idea I dont suggest it) and after I got the rest of my mods the car feels better than ever before...so what does that meen...buck up the 75 bucks and get a pulley!
09-10-2004, 07:51 PM
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haha yeah the smaller pulley is well worth it I'd say. Between it and the filter its like I put another engine in the trunk.
Has anyone looked into the backpressure thing any? The octane thing is done (I think) so I'd like to hash this out if anyone is into it....if not oh well
Has anyone looked into the backpressure thing any? The octane thing is done (I think) so I'd like to hash this out if anyone is into it....if not oh well
09-10-2004, 08:01 PM
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Originally Posted by DrJay
haha yeah the smaller pulley is well worth it I'd say. Between it and the filter its like I put another engine in the trunk.
Has anyone looked into the backpressure thing any? The octane thing is done (I think) so I'd like to hash this out if anyone is into it....if not oh well
Has anyone looked into the backpressure thing any? The octane thing is done (I think) so I'd like to hash this out if anyone is into it....if not oh well
LOL DrJay are you a lawyer???....cause you sure like to debate!!!
09-10-2004, 08:05 PM
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I've been told I should be 
My deal isn't so much with debates, which I do enjoy...If I'm right! haha
I've just been doing a lot of research and come across a few myths that I feel people should be aware of. At least I believe they are, if I'm wrong I'm wrong but with that I realize that it will take nothing less than a debate to convince people. Hell the octane thing took 6 pages to quell.
My deal isn't so much with debates, which I do enjoy...If I'm right! haha
I've just been doing a lot of research and come across a few myths that I feel people should be aware of. At least I believe they are, if I'm wrong I'm wrong but with that I realize that it will take nothing less than a debate to convince people. Hell the octane thing took 6 pages to quell.
09-10-2004, 08:13 PM
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Originally Posted by DrJay
I've been told I should be
My deal isn't so much with debates, which I do enjoy...If I'm right! haha
I've just been doing a lot of research and come across a few myths that I feel people should be aware of. At least I believe they are, if I'm wrong I'm wrong but with that I realize that it will take nothing less than a debate to convince people. Hell the octane thing took 6 pages to quell.
My deal isn't so much with debates, which I do enjoy...If I'm right! haha
I've just been doing a lot of research and come across a few myths that I feel people should be aware of. At least I believe they are, if I'm wrong I'm wrong but with that I realize that it will take nothing less than a debate to convince people. Hell the octane thing took 6 pages to quell.
But I do agree sometimes it takes a good debate to squash the myths....by the way ill never use anything but 91+ octane in my cars......I dont care if I can get away with it or not!
09-10-2004, 08:15 PM
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Heey I'm not out to convince anyone to use less...but if any of your buddies start talking about how you'll destroy your engine with it you can say "If your sensors are in proper working order, no you won't....BUT <insert personal paranoid thoughts here>... haha :P
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