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removing the cat...

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Old Aug 7, 2002 | 09:42 AM
  #1  
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blah blah
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Default removing the cat...

if i woould remove the cat..and the resignatior...leaving my stock muffler....will i gain any power?? will there be any sound coming out??
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Old Aug 7, 2002 | 12:09 PM
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unless you're pusing a turbo or something.. the loss in backpressure by removing the cat and resonator(s?) will kill your low end torque and 99.9% give you little to no gains up top.

in short.. dont do it unless your cat is decayed and you dont wanna replace it.
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Old Aug 7, 2002 | 06:14 PM
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Why would you want to go thru the trouble of remoiving your cat and resonators if you're going to leave the uber restrictive stock muffler in place?
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Old Aug 8, 2002 | 03:59 AM
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Originally posted by GimpyAccord
unless you're pusing a turbo or something.. the loss in backpressure by removing the cat and resonator(s?) will kill your low end torque and 99.9% give you little to no gains up top.
This is incorrect.

Any properly designed exhaust system will have back pressure, in an acceptable range. When modifying/ changing your exhaust, you want the lowest back pressure you can get away with [allows the engine to breath, zero load rev speed increases, and so does heavy load rev speed], while keeping exhaust velocity optimized for the RPM range you're looking to make power.

That said, a gutted cat will cause loss of power in most cases, but NOT due to lack of back pressure, it will cause loss of power because of a reversion effect, where exhaust velocity slows down, and some sound energy is actually reflected back towards the cylinders [good for 2-strokes, not for 4-strokes]. If the removed items were replaced with suitable sized tubing, this would not be a problem, however, the exhaust velocity would be high enough by the time it reached the stock muffler that you may actually be trying to overstuff it, and INCREASE back pressure, loosing power. It really depends on the condition of the components, the size of the tubing, output of the engine, and layout of the exhaust, but again, you want to lower backpressure, but optimize exhaust velocity.
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Old Aug 8, 2002 | 05:01 AM
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get a hi-flow cat.
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Old Aug 8, 2002 | 09:14 AM
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straight pipe from the header back.... can't go wrong
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Old Aug 8, 2002 | 12:06 PM
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Removing or altering your catalytic converter is a Federal offense and punishable with a 25,000 dollar fine. Is the potential gain worth $25k? Thats what you've got to ask yourself :thumbup:
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Old Aug 8, 2002 | 12:08 PM
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Originally posted by TheRooster
Removing or altering your catalytic converter is a Federal offense and punishable with a 25,000 dollar fine.
Not on a 1967 Jaguar XKE or any car made prior
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Old Aug 16, 2002 | 11:27 PM
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dude to make it short and sweet

if you chop that thing off... watch out cause your neighboors will here you from 20 blocks away

my friend did a straight pipe back to a aftermarket exhaust and it was the loudest crap sound you would hear... specially sitting in the car for long periods of time
its a weed wacker with nitrous basically

plus it would back fire like crazy
its not worth the time and effort
you will regret it in the end
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Old Aug 16, 2002 | 11:29 PM
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just so you know... it was so bad on my friends integra that he spent the 250.00 to get a high flow cat and a catback exhaust cause he couldn't take that deadly sound anymore
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