anesthes

I'm thinking of selling my long-tube headers, and buying a set of shorty headers. The car is just too loud. I think the shorty headers will reduce a ton of noise.

What do you guys think?

I have the Hooker 2149 headers. I'm thinking of getting the 2061 shortys.

Rest of the system is true dual 2 1/4" pipes, H-pipe, dual cats, turbo lt1 mufflers.

-- Joe

mseven

I would try and work with it more before doing that. There maybe some options as to a resonater, I think bassani, and magna flow has a 2 in 2 out version.

tequilaboy

I'm pretty sure my car got a little quieter going from factory manifolds to long tubes. Definately a more "harmonious" and smoother sound with the LTs.

I would think shortys would be a bit louder than cast manifolds, and maybe eve louder than LTs, due to the exhaust blending at uneven intervals farther upstream with more energy.

A magnaflow x-pipe helped quiet it down some more. I'm running flowmaster 50 series and 2 1/4" tubes, no cats. Its almost too quiet sometimes.

X vs H-pipes can sound differently. An X or resonator or quieter mufflers would seem reasonable to try first.

Do you think the thin tubes themselves are vibrating more and emitting airborne noise? Is your exhaust securely mounted and isolated from the rest of the chassis?

Maybe try some band clamps around some of the tubes to stiffen them.

bogus

I am with tequilaboy. I suspect you have a tuning issue here.

The shorties won't buy you anything... except less power and the potential for more ringing.

I suspect you have 2 problems... the h-pipe is simply not as good a way to balance the two sides as an x-pipe is. And the mufflers you are running.

C4DC

I agree with those above who say to look further into the other components of your setup. I'd look at some tamer mufflers 1st imo.

anesthes

Hrmm.. See I was thinking that the long tubes create more exhaust note do to the tuned length of the pipes.

I think a lot of the noise is resonating on the hatch. Do convertibles have the low rpm drone that coups have?

-- Joe

BrianCunningham

Header wrap will help abait some of the noise, as well as keep the engine compartment a little cooler.

The turbo mufflers are probably what's doing it to you.
The stock mufflers actually flow pretty well.
You might try them out on you system.

MTVette's has long tubes and the stock mufflers on his car.
I've seen it run, it's not that bad.

JohnyH

The vert was worse for a resonance and drone, I put Corsa cat back on and I'm very happy with the results!

anesthes

I wonder why that is.

My car is NOT loud outside.

It's loud INSIDE. hardcore.

-- Joe

86VX1

i agree with others saying that shorty's will actually be a bit louder, but i don't think getting rid of your h pipe and replacing it with an x pipe will fix the problem. it will make a barely noticle difference.
my current exhaust is lt's, to x pipe to flowmasters. when i replaced the h pipe to x pipe the only difference i noticed was in the rpm, and it was smoother revving but the noise was the same. it's difficult to explain.

i agree with cunningham, look into changing to a different muffler or adding a glasspack in the middle to act as a resonator.

F1Fan

You'd take a hit performance wise if you got rid of them.
Is it more of a resonance/drone issue since your saying the problem is on the inside of the car? Do you have a certain rpm band where it's worse, and is acceptable outside that rpm band?

fwiw, according to the previous owner of my car, the resonance is worse now with the x-pipe than previously with the h-pipe. Either way, it's very loud inside. (LT's high flow cats, x-pipe and Borla catback)

If and when money allows, I'm hoping to pick up a Corsa system and just be done with this.

anesthes

Yep, its only when the motor is loaded under cruise, below the RPM band. I'm gonna try a smaller cam , but i'm not 100% convinced it will go away. The problem is pretty much anything under 2,000rpm.


-- Joe

F1Fan

My resonance problem seems to be about 2000-2200 rpm, kinda the cruise rpms unfortunately. I think you can solve this by some exhaust changes downstream of the LT's. I've considered placing a call to Borla to see if I can still by the resonator that originally came with the system. That (as others have suggested) would probably make a pretty big difference in your case as well. I just hate to see you ditch perfectly good performance parts, that stuff ain't cheap!

anesthes

I hear ya. The car is fast as heck, but it's not fun to drive. It sits in my driveway. I drive it maybe once a week. I can't even take it to the beach without going deaf. It drives me batty.

I'm not sure where I will fit a resonator though.

-- Joe

Mr. Peabody

Put stock mufflers on it.

coupeguy2001

I have the same problem. When I ordered the new mufflers from mid america, they told me they were out of the ones I requested and sent me a set of pacesetters. They were supposed to be an upgrade from the ones I ordered.
They are way loud inside the car, and loud outside as well. my wife hears me coming with all the doors and windows closed, and the resonance is deafening.
I made muffler hats to deflect the sound away from the car to the street, but they help only a tiny bit. Then I put dyna-mat under the hats, and it helped a little more. Then I lined the cargo and storage areas with dynamat, and it helped some more. Then I lined the area behind the seats with the dyna-mat, and it helped a little more.
now, I can tell the radio is on above 2200 RPM, but hear it clearly on the freeway at 75 MPH @ 1750 RPM, and the noise starts buzzing as I get closer to the 2000 RPM mark.
It's clearly resonance. resonance is the sound waves out of sync. Corsas are supposed to cancel the sound waves, but geez, they are only mufflers. They are an expensive way to get rid of the noise.
I think it has to do with the cam lobes for the TPI. If it didn't, then why don't other Chevies have this problem?

Fuzzy Dice

I think the issue is not the long tubes...I have long tubes and an X-Pipe, no cats or pre cats back to stock mufflers and it is fine...no resonance...

anesthes

It did it with BRAND NEW stock mufflers too!! I threw them out after just 3 months of use. It was suggested that I go true duals with an H-pipe, and turbo lt1 style mufflers. Didn't make any difference.

-- Joe