Rasp w/o resonators

sc186 · 12-02-2004, 01:49 PM

Has anybody who replaced their resonators with either a straight pipe or moroso spiral flows noticed any rasp or clicking sound under throttle with the windows down?

The reason i ask is because i bought the JBA setup and had considerable rasp. I tried replacing the muffler with a dual in single out magnaflow to no avail. I am wondering if it is maybe the JBA resonators causing the rasp and what i can do to eliminate it. My truck sounds like a raspy civic under load.

To: The Head

Did those moroso spiral flows give a nice clean sound?

juma · 12-02-2004, 03:44 PM

do you hear it at all rpm's or is it just a certain rpm range you hear it in? if so, what rpm range?

not likely the resonators "cause" rasp. they are intended to absorb noise within a certain frequency range. they just don't have the rasp noise frequency range covered, I speculate. another resonator may work better.

juma

sc186 · 12-02-2004, 09:04 PM

all rpm's under load. it sounds extremely annoying. im guessing that the reason that JBA is redoing their exhaust is because of this.

By the way, they still have not responded to me. Not a very good company in my opinion.

sc186 · 12-03-2004, 09:54 PM

Bump. anybody?

pciley · 12-05-2004, 11:28 AM

YES just saw the thread... sorry. Swapped my resonators with 3" straight pipes, upstream of the Banks exhaust.

TONS of rasp. I don't hear it with the windows up, only down, or if girlfriend is driving the truck and I am outside to hear it.
Seems to quiet down after its warm though.
I thought there was a leak at one of the flanges so I installed NEW gaskets from Banks (had reused the old ones and they were falling apart) on all 4 flanges, both ends of the straight pipes, DIDNT help at all, no leaks. I guess that's just the sound that was being baffled by the resonators. That was their job, to quiet the exhaust.

sc186 · 12-05-2004, 10:36 PM

awesome. well kind of. I was under the impression that my truck was a freak of nature. I will for sure be re installing the stock resos now. Thanks for the reply.

pciley · 12-06-2004, 09:36 PM

.. to each his own. I prefer performance over aesthetics, but an equal mix of both is good too.

sc186 · 12-06-2004, 09:43 PM

Id hardly say the performance difference offered by removing the resos is worth having the terrible rasp that i have.

It is funny because as you said, i also though that i had an exhaust leak and spent several saturdays under the truck installing new gaskets and such for no reason.

Hopefully i can get around to having the resos replaced on thursday. If so i will let everyone interested know how it turns out.

pciley · 12-07-2004, 11:09 PM

The resonators you have are from the JBA cat-back exhaust system, right? Maybe try what I did and have custom 3" Mandrel bent straight pipes made. You will probably get a bit more "umf" out of them.

Also, I'm not sure on the tubing diamater on the JBA, but the Banks was 3" so the custom pipes bolted to the Banks cat-back really nicely.

Again, the raspiness I get is only audible when the truck is cold, and for the first couple of blocks/miles of driving. When I get out of my neighborhood and onto the main street, it goes away. I even travel right past a tall cinder block wall that bounces the sound back at me, and with the windows down after the truck warms up, there is no more rasping.
Mine was like a slight ticking upon each piston firing. It sounded JUST like a leak, but after laying under there, hands and ears all over the flanges, there was NO leak.

pciley · 12-11-2004, 01:29 PM

I noticed yesterday that there is no more rasp or ticking from the exhaust. I guess it has finally broken in. Maybe the seals on the straight pipes just had to heat up and cool down a few dozen times before they lost the gaps or something.
Anyways, thought you might want to know. Maybe it is just the colder weather or the crappy winter gas around here.