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Discussion Starter · #1 ·
This is mostly a question for ppl who have pacesetter headers, i know they do not have the U turn after the rear primary like factory and other headers. Could this be why i hear a rumble in the low rpm after letting off the gas and letting the car decelerate? it comes on and off at 2k and 3krpm usually, it also sort of vibrates the floor( i can feel it in my feet when on the pedals ).. i also hear it when reversing.. Does anyone else have this noise with PS headers?
 

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SilverLS said:
This is mostly a question for ppl who have pacesetter headers, i know they do not have the U turn after the rear primary like factory and other headers. Could this be why i hear a rumble in the low rpm after letting off the gas and letting the car decelerate? it comes on and off at 2k and 3krpm usually, it also sort of vibrates the floor( i can feel it in my feet when on the pedals ).. i also hear it when reversing.. Does anyone else have this noise with PS headers?
This sounds more like you don't have a resonator, or the one you have sucks/went bad.

The U in the factory Y-pipe is called a "semi-dual exhaust" in the KL engine SAE paper, and is primarily related to torque peak. Not sure how it affects sound quality.

-Garrett
 

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Discussion Starter · #3 ·
no, it comes from in front of the firewall, i had a resonator installed a few days after i got the headers cuz it was so loud!!
doesnt anyone else with pacesetters have this noise?
 

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yes thats exactly what causes it. The bend in the pipes is to get the collectors from the front and rear exhaust banks as close to the optimal "equal length" (which really isnt perfectly equal) as possible...

The vibrations and noise youre feeling are the exhaust pulses fighting eachother... ie: the resonant frequencies... its not quite rasp but similar. the factory exhaust was designed to allow the exhaust pulses from the front and rear banks to exit into the exhaust stream one after the other... very smooth... once you remove that bend, you have a rear bank thats much shorter than the front bank.. you lose some of the scavenging effect (but its more than made up by the larger diameter piping and individual cylinder pipes... but a sideeffect is that wierd resonance. anything downstream wont help much either... maybe quiet it down a bit.
 
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