strange noise after header install?

[dudeling7]

Hey there, i have recently put on some xforce 4-1's on my integra B18b. i also added a flex pipe and high flow cat while i installed it. i have a 2.25 inch cat back system with a large resonator in the b pipe.

after i got the header, flex pipe and hgh flo cat installed i now get a buzzin sound - its tinny and kind like a resonance at around 3000 rpm and thenagain higher up in the range when i am going hard on the gas. what could be causing this sound? it was never buzzy or anything high pitched when i only had my cat back. also i checked at a exhaust shop and there are no leaks in the system. thanks alot! any help would be good.

apart from that the 4-1 headers give eally good topend. from 4000 rpm onwards is awesome and i didnt rally lose any bottom end.

[khOa`]

maybe a gasket somewhere in the exhaust system might've cracked/ripped but then therez quite a lot of gaskets to check, one from header to cat, another one from cat to flex pipe another one from flex pipe to catback. anyways hope you find the problem and get it fixed, goodluck

[simbadda54]

blow engine kev. Needs a k20a swap

[Tobster]

"Resonance" is exactly what you've got. All exhausts have a resonant point somewhere in the rev range -- it just depends on how strong it is due to the nature of your exhaust. It's like feedback in a sound system where a certain frequency becomes amplified.

There are a few things you can do to try to avoid resonance.
You could try dropping another resonator (hence the name) into the system.
Most name-brand mufflers have their name embossed into the casing: this isn't just wank factor: it can reduce resonant sound because it changes the otherwise continuous smooth shape of the muffler (and hence makes it more difficult for sound waves to find a single resonant pitch). Changing the muffler will probably help.
Supposedly dual-walled muffler tips can also help prevent resonant sound -- more than single-walled tips.

[dudeling7]

ill prob take it to a shop and ask them. are there any areas where resonators can be placed for certan resonance areas? like certain areas on the bpipe.

[EK4R]

my mate got the same prob, and he has a x-force too, apparently its common with x-force. not sure. he got a lil gap between the gasket and airs gets through. not expensive to fix, just need a proper job done.

[dudeling7]

my mate got the same prob, and he has a x-force too, apparently its common with x-force. not sure. he got a lil gap between the gasket and airs gets through. not expensive to fix, just need a proper job done.

hey man do u know which one of hte gaskets air was comming in through? on mine it sounds like its from the cat area.

Yeh thanks claymore that was one of the things i was going to check - the heatshield.

[EK4R]

not sure buddy ask preludacris :) hehe

[dudeling7]

on further inspection and after driving for a while its not really a buzzing noise anymore......

but after installing the headers after 5000+ rpm its very high pitched....when before it used to sound grunty. is this just because of the header install and increased flow? will another (2nd) resonator help make it less raspy?

[Limbo]

its the headers. They are thin stainless steel, thus the noise your hearing is the exhuasts merging into the collector. Its a common thing with 4-1 headers that are SS.

A way to reduce the noise abit is to heat wrap them. keeps the noise and heat in.

I've had 4 sets of headers and all the 4-1s have this problem

[dudeling7]

so only heat wrapping will do this?? adding another resonator wouldnt help with this noise at all? only quieten it down a little?

[Limbo]

adding a flexi, proper gaskets between the joins, extra reasnator better exhaust will all help, but you cna't predict until you actually do it the extent.

Wrapping helped mine stop the swishing noise fron the extractors. It thickens the extractor walls and deadens the sound slightly.

How much work have you done on your exhaust? is it only headers you changed?

[dudeling7]

Ive got the whole exhaust system done.

so it consits of 4-1 header into a flex pipe and then high flow cat, one resonator and a straight through muffler all of it 2.25 inch.

so did you heat wrap the whole header or only the collecter area? i may add another resonator to see what effect is has. do you know any quality mufflers which may work better?

but yeh i see what you are saying in that adding hte headers there seems to be much much more flow compared to stock so there is much more noise too.

[TECBOY]

check the flushness of the fitting of the headers. there may be a leak causing the problem. also check surrounding areas incase something was bumped

[dudeling7]

yeh its all sitting well where the headers connect to the block, the sound seems to be comming from the cat area....

do new hi flow cats usually sound much louder or harsher? maybe my old one was so clogged up haha. im going to check to see if the heat hield under the car is touching at all. fter installing the headers i also get this ticking noise but the exhaust place couldnt find any leaks. :(

[Limbo]

I wrapped from header to collector.
I relation to getting it quieter, i first had a twinloop it really helped with the noise, then later i got a very large body canon for better flow. It really helped with the noise, but the twinloop is the quietest muffler i ever had.

My system is a 2 1/4, JDM 4-1, single reasonator and a very large canon


yeah hi-flow cats are louder.

Ticking noise could be the different cooling of the different metals.
S/S heats up and cools faster than mild steel. The wrapping might help abit with this also as it keeps the heat in.