hi i was wondering, u know on some cars with a muffler or exhaust when they give it gas it sounds good but when they let off the gas it sounds wierd like spitting/rumbling sound? what is the cause of this, is it because of backpressure and its direction and how can they be prevented? thanx
oh ya i also forgot to ask, if i get custom piping 2.25, leave my stock cat on and also put on a resonator, and put on those cheap mufflers from ebay, well i even notice a difference?because the stock cat is still on??or will i might even lose power?
i asked about it a while ago, i dont know why it does it.
The noise you are referring to could be attributed to many different things. Unless you are running an aggressive cam profile, what you are most likely hearing are changes in exhaust discharge velocity and the resulting turbulence within the ehaust system.
Another possibility could be a clogged/semi-clogged catalitic converter.
If the noise is due to a clogged cat, replace it.
If the noise is due to velocity changes, a more freely flowing exhaust system may reduce the noise or it may actually make it louder, but I wouldn’t worry too much about it.
As to your second question, so long as everything is a matched diameter from the cat back, you should feel “some” gains in performance. The gains probably will not be as substantial as you would get with a high end exhaust system.
As for the stock cat replace it with a high flow one now and you will love yourself for it later.
I would assume that the reason why it does that is because the car is decelerating, but not getting air into the cylinders so its kinda working harder to suck in air, which makes the sound.
Since the TB is closed, then your not getting the same amount of air in the cylinders and the same amount is not coming out of the exhaust so the sound waves and airflow are being affected within your exahust system again making the sound different.
Not scientific fact to back it up, but it makes sense.
aight thanx you guys…by the way i was wondering u know those bomz muffler, what are inside of them are they glass packed? cuz i been reading and ppl say it melts, if it is what about spw muffler, they are “Stainless steel wool with densely packed double layer rockwool,” does anybody have a spw muffler?if so how are they?
the “spitting/rumbling sound” you hear are backfires . . . all Hondas do it. You just can’t hear it because on a stock car because the mufflers are too quiet. I can’t recall exectly what causes it (something to do with the way the ECU sends signals to the injectors, and they still provide more fuel when decelerating or something?), but you can usually cause a bigger pop of you let of the gas, then blip the throttle (barely opening), then let off again.
Steve (who’s too lazy to look up the full reason for these backfires)
There’s a video floating around somewhere of Tony the Tiger’s G3. It lets off the most wicked sounding backfire (gunshot) I’ve heard from a Honda. Then again, his car is a freak…
On more civilized setups, a resonator will usually take care of the noise.
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Tom
When i let off the gas it sounds like a 2step… or a jake brake. 