bypassing the catalytic converter
11-26-2011
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bypassing the catalytic converter
is bypassing the cat a good idea ? what's the horesepower gain of doing this ? can one run a valve controlled pipe in parallel to the cat without removing the cat ? so when the valve is open the back pressure is reduced and when the valve is closed everything goes through the cat. Any insights on this subject
11-26-2011
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Rep Power: 169 Re: bypassing the catalytic converter
The point of going without a cat is to reduce back pressure. It sounds like a good idea, but the air flow going from the headers to about after the flex pipe is the most important in reducing backpressure. the turns the exhaust has to take to bypass the cat would cause back pressure. the y pipe that you would fit in there would also caust back pressure no matter which path you have open because its not smooth.
Personally, I would weld in an lx downpipe with no cat, and then make the cat on the bypass pipe. a lot of work, but you could have an electronic switch when you get to a certain rpm so you could have good tq at low end and hp at high end. plus youd fool the emissions people XD
Personally, I would weld in an lx downpipe with no cat, and then make the cat on the bypass pipe. a lot of work, but you could have an electronic switch when you get to a certain rpm so you could have good tq at low end and hp at high end. plus youd fool the emissions people XD
11-26-2011
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Re: bypassing the catalytic converter
somewhere between 0.1 and 0.2 horse power gain on an otherwise stock engine, with an increase in emissions several fold.
11-27-2011
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Rep Power: 210 Re: bypassing the catalytic converter
1. Get an actuated valve. They start at about $60 and they look like this:
2. Have the muffler shop weld it in the straight portion of the pipe in front of the cat. Should cost $50-100
3. Wire it to a switch for the emissions test and those pesky officers.
2. Have the muffler shop weld it in the straight portion of the pipe in front of the cat. Should cost $50-100
3. Wire it to a switch for the emissions test and those pesky officers.
Last edited by lazlong; 11-27-2011 at 12:09 AM.
11-27-2011
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Rep Power: 163 Re: bypassing the catalytic converter
most shops wont weld that in there...becasue "they can be fined" for bypassing it.
however good find. i didnt know such a thing existed, but still theres really no point becasue you wont feel any gain at all and would just be smoggin it up. now with headers and thicker pipes...maybe
however good find. i didnt know such a thing existed, but still theres really no point becasue you wont feel any gain at all and would just be smoggin it up. now with headers and thicker pipes...maybe
11-27-2011
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Rep Power: 787 Re: bypassing the catalytic converter
better bet if youre worried about air flow is a muffler with valve that opens and closes depnding on how much exhaust is being pushed (based on engine rpm) like the rsx type-s jdm exhaust.
or just take the headers clean off and run it like that.
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