Question about exhaust without flex pipe
Joined: Apr 2009
Posts: 344
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From: Vancouver BC
Question about exhaust without flex pipe
Hi,
so i have a Greddy EVO2 exhaust and HFCs/art pipes on my coupe and i keep scraping the flex pipe and i've seemed to have cracked it already and it's leaking.
i'm strongly contemplating replacing the flex pipe with just a straight pipe..
The flex pipe is on the x pipe.
what i'm worried about is vibrations and stuff the flex pipe would absorb.
what i'm hoping is that i can get away with this and if necessary put stiffer exhaust hangers on as well.
any opinion guys?
so i have a Greddy EVO2 exhaust and HFCs/art pipes on my coupe and i keep scraping the flex pipe and i've seemed to have cracked it already and it's leaking.
i'm strongly contemplating replacing the flex pipe with just a straight pipe..
The flex pipe is on the x pipe.
what i'm worried about is vibrations and stuff the flex pipe would absorb.
what i'm hoping is that i can get away with this and if necessary put stiffer exhaust hangers on as well.
any opinion guys?
I wouldn't straight pipe it. I'd find a stronger flex pipe.
Any movement from the engine will try to torque the entire exhaust system and will break at the point of least resistance. If a cap plate on a cat or resonator is thin enough, the engine movement will eventually deform it enough to break it.
Stronger exhaust hangers will only make the problem worse. At least with weak hangers, the exhaust will be able to move a little bit with the engine. With stronger hangers, it'll isolate the area that moves the most (most likely at the flex pipe location) and break something there.
Find a better flex pipe and install it.
Any movement from the engine will try to torque the entire exhaust system and will break at the point of least resistance. If a cap plate on a cat or resonator is thin enough, the engine movement will eventually deform it enough to break it.
Stronger exhaust hangers will only make the problem worse. At least with weak hangers, the exhaust will be able to move a little bit with the engine. With stronger hangers, it'll isolate the area that moves the most (most likely at the flex pipe location) and break something there.
Find a better flex pipe and install it.
You don't want to get rid of the flex pipe, without it you'll develop cracks elsewhere thru vibration. Replace it and add another hanger so it will be higher and secure....
Gary

Gary
I agree
I agree with the previous post. There's an alarming number of people on this forum with cracked headers. I believe it's due to aftermarket exhaust systems that are completely rigid all the way back. Also most high flow cats and test pipes remove a factory brace under the catalytic converters, it supports the weight and provides an anchor point. I recently installed a Stillen true dual system and Ichiba headers. The new system doesn't have any flex pipes and when I have some one rev it up when I'm under the car the whole system flexes and twists with engine movement! Scary to say the least! Considering what a pain it was to install the headers, I'm in the process of installing some flex connectors in the x-pipe to protect the headers. I know all flex connectors leak eventually but I would rather replace them than the headers.
These are the flex pipes I ordered, they were about $40 each. If you can't weld them yourself a local muffler shop can do it fairly cheap.
http://www.summitracing.com/parts/SUM-642510/
These are the flex pipes I ordered, they were about $40 each. If you can't weld them yourself a local muffler shop can do it fairly cheap.
http://www.summitracing.com/parts/SUM-642510/
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