Resonators..... should I use them on my 68 Wagon
 

Earlier this summer, I put a pair of Dynomax 17749 mufflers and 2 1/2" Flowmaster tailpipes on my clone wagon. It has the RA exhaust manifolds and currently has a 68 350 engine built to HO specs. The tailpipes now run out the back of the car under the rear bumper.

I expected the new mufflers to quiet down the car a lot. In the end, it did get rid of the drone, but is still fairly loud when idling. At this point, I'm not sure if I will change anything or not.

I have a new (still in the box) stock Gardner exhaust system for my 68 Firebird (400 HO spec engine) and it has a pair of resonators that go in front of the transverse muffler. I'm wondering if maybe I could put a pair of the tube type resonators in front of the dual mufflers on the wagon and what that would do to the sound at idle. I'm okay if performance suffers a little as I'll never push the car hard anyway.

Short of that, I suppose I could swap out the mufflers again or put sound deadening mat under the carpet. I don't think an X-pipe would help at idle, or would it? I'd like to take the easiest route possible.

Looking for suggestions. Thanks

Old Joe

I would not break up my Gardner exhaust set….. That said, quiet is cool and I’m sure a local muffler shop could set you up with something similar to what came in your Garnder set.

In my own experience an H pipe will take away some of the objectionable noise as well as pick up a little low, and mid range torque. I used a 2 inch pipe for the crossover between the head pipes in a few customer cars as well as my own.

It will change the exhaust note some, just to be forewarned, but I always thought it was favorable to just true dual exhaust sound, especially if the exhaust crackled such as glass pack mufflers do.

:2cents:

My '66 GTO has a solid roller with Doug's round port headers with 3" exhaust all the way back. I used Dynomax Super Turbo mufflers which were fine drone-wise, but too loud. I added resonators downstream of the mufflers like the stock setup was, which made a significant difference. The body length of the 24222 is only 12" long and looking thru it you'd swear it wouldn't make a difference...but it does.


https://www.dynomax.com/mufflers/rac...ullet-mufflers

This is pretty much what I was thinking of except the resonators would be upstream of the mufflers. I mentioned my firebird exhaust system only for reference purposes because the stock system had the resonators upstream too. Since these tube type resonators (glass packed mufflers) are so small, they would be relatively easy to fit into place. From what I read, the farther upstream you put resonators, the quieter it is for the interior of your car. I have zero experience with this, so I'm only going by posts from other sites that I read online. I've never done an H pipe, but seems like it might take a bit more fitting and I'm thinking the resonators would be more likely to give me what I'm looking for.

BTW, I don't want to give the impression to anyone that my wagon is loud. I'd say it has a very nice sound while cruising. My neighbor has a C7 Z06 Vette and I'd say my wagon has about the same sound level at idle as his car. The problem is my hearing sucks (product of loud everything as a teenager). I can't hear anything clearly when there is too much background noise, so I have to keep exhaust sound low. :rolleyes:

I have Gardner resonators downstream of the same mufflers as you on my GTO and its very quiet.