The Stovebolt Site Forums The Shop Area The HiPo Shop Exhaust system too loud

I put Fenton headers on my '54 with a 248. Then I had the same glaspacs put on it that are on my '56 with a 350. The '56 sounds deep and mellow. The '54 sounds loud and obnoxious.

I first asked about this on the Sub and Panel forum because it was suggested that it just sounds loud because it is a Suburban. But I have discounted that. It not only sounds loud, it is loud. I got some suggestions over there but I'm hoping someone here knows something about how exhaust systems work and can help me with a solution.


The installer claims it is the difference between a 6 cyl. and an 8 cyl. But I know of several pickups in the area running Fentons and glaspacs that aren't this loud. They won't do anything about it unless I pay more money. I already paid $100 more than what I paid for the '56 system. They aren't getting any more of my money.

Now I need to figure out how to fix it myself. It seems to me that there is some kind of acoustic effect taking place here. It seems to be amplifying the sound at certain rpms. As I go through the gears it goes from tolerable to obnoxious. And at highway speed it sounds like straight pipes.

I'm thinking about adding another set of mufflers near the outlet. My reasoning is maybe the long pipe after the muffler is making it sound obnoxious. The '56 pipes are shorter, exiting just forward of the axle. The burb pipes go all the way to the back. Any comments on that theory?

Or do I need a crossover pipe as was suggested in the other forum.

Or? Any help will be appreciated.

If you have both pipes go into one glass pack it will sound better ,in my 2 cent opinion. Also larger pipes on the rice burners makes that sound I don't care for also. I have the fentons on my 302 GMC the dual pipes go into the muffler with dual inlets and dual outlets. I used the medium muffler from WALDRON'S EXHAUST. The pipe stops just after the back of the cab with turn down's. http://waldronexhaust.com/shop/index.php
They have videos on YOUTUBE. You can listen to many types of systems there.

Cletis -
Both of you solutions will help.
The cross over pipe helps balance the sound and will make it somewhat less noisey.
Also, remember, the longer the tail pipes the louder it is. So, another set of mufflers further down the line toward the back would also belp make it even less noisey.
In short, you have just about the two best ideas to accomplish what you need to do with the first idea probably being the cheapest and the second being more money, but more solution.

Cletis, do you know how to fabricate and weld exhaust tubing? If so, you can put a connecter between the 2 exhaust pipes in front of the mufflers, what is called an "H" pipe on an 8-cylinder application. That adds torque and reduces noise.

Further improvement is available from larger, quieter mufflers. Loud exhaust systems are very annoying to people inside of and outside of the noisy vehicle, so it's understandable that you want to quiet it down.

I just bought a piece of pipe cut and ground it to fit and welded in place works fine but probably leaks on the top a bit where I couldn,t reach very well.

I drive mine daily so I just use use quiet mufflers, Walker 18234 last time, with 2-1/4 in 2 out.

I believe an x-pipe is your solution. The X really quieted down my 30" glasspacks from Fenton's, 2" pipes. Some major co. sells an 'X - Muffler', two in, two out with a perforated X inside to diffuse and muffle the exhaust.

Although I love the sound of straight pipes with burned out shorty glasspacks, I only love the sound for about ten seconds. As below I just returned from a 900 mile round trip at Thanksgiving, listened to MP3 driven speakers the whole way.

Cletis:
Just read an ad in Classic Trucks Feb 2011 issue you might be interested in. Dynamite Dumps..Sound Suppression inserts. Made to quite pipes and increase power etc. Web site is...

www.carchemistry.com

Don't know if it will fit your application..just thought I would share the info I saw.
Take Care

Thanks Jimmi, but all I found there was headers for open engine cars.

I have ordered a couple of Walker 17852 mufflers. I intend to use them in addition to the glaspacs. I will mount them close to the exit.

Cletis -
You may find that after you get the Walkers mounted, they might be just fine by themselves and you can pull the glasspacks. Don't overlook the possibility of doing that in order to keep your back pressure in check.

Aren't the dynamite dumps for race cars? They might be a little loud.

I thought they were just baffles for the dump tubes.

I have Fenton's and I use a dual side by side system with a single Magnaflow (2 1/4" X 2 1/4") muffler. It sounds good but won't blow your ear drums out. Check it out on the Magnaflow website.
Normbc9

I was really looking forward to seeing (and hearing) videos of some of your exhaust systems. Anyone feel like shareing?

By the way, I run the computer through my stereo system so when I find a video of sweet straight six exhaust, I like to crank it up and yell "hey honey, listen to this!". hehe, good times.

Update: With the Walker mufflers installed near the rear of the truck, in addition to the generic glaspacs, I get a sound I am happy with. Loud but mellow when winding through the gears, quiet and mellow on the highway.

The mufflers I've used on projects for a lot of years are originally for mid-1970's Cadillacs. They're designed to flow exhaust for a 472 or 500 cubic inch V-8 through one muffler. They're 2 1/2" diameter in and out, and they're nice and quiet. Dual pipes with one muffler each have virtually no backpressure, regardless of how big an engine they're on, and I don't have to listen to exhaust pipe resonance that gives me a headache!
Jerry

What muffler would make a slight tone. I want a little bit of sound but so much I can't carry on a conversation. Back in the day I had a 1969 Buick GS. It had a bit of a metallic sound and one I would like to duplicate.

Split-manifold inline sixes have more of a problem with resonance in the pipes than actual decibel volume of noise. The classic sound for 1950's dual-exhaust stovebolts involved steel-pack straight-through flow mufflers called "Smitty's", which enhanced the resonance and gave a "BRRRRAAAAAPPPPP" noise at big throttle openings. They were only mildly obnoxious at low RPM and part-throttle settings. It's hard to get just a little exhaust noise, like it's hard to be a little bit pregnant. As the muffler(s) get a little age on them they get louder.
Jerry

I know Walker and other muffler companies make a variety of mufflers with a variety of decibels. I just don't know which is which. It's like buying a bed without testing it for a few nights. They're hard to return.