The Stovebolt Site Forums The Shop Area The HiPo Shop Muffler advice

I'm trying to figure out what mufflers to put on my truck. I have Fentons and dual pipes. I want something that has a low pitch, not an annoying high pitch buzz. I don't want the truck to be quiet, but I don't want it obnoxious either. I at least want to hear the lopey cam at idle. How would an H-pipe change the tone? What are you guys running in a dual setup?

you may want to try a set of the old original Smitty's. It just takes a while for them to burn out a little to really sound good. Won't burst your eardrums either...just a suggestion.

Hmm..I thought Smitty's were really loud and had that RRRRRRRAAAAAAAAPPPPPPP noise under full throttle. Or am I thinking of something else?

6-cylinders in general, and I-6's in particular will have a few RPM ranges where the exhaust note will resonate and become irritating to anyone who hasn't blown his ears out with rock music, or in my case, jet engines, race cars, and deer rifles. The trick is to position the muffler(s) somewhere in the exhaust stream where the objectionable BRRRRRRAAAAAAAPPPPPPPP noise doesn't happen during normal driving. Moving the muffler to different positions in the exhaust stream is one way, or adding a second small muffler as a resonator, or adding a crossover pipe will change the resonant RPM. The other way is to install a very quiet, low-restriction muffler, but that eliminates almost all the sound. That would be my choice!
Jerry

I like turbo mufflers, placed as far back as possible.

cm

Thanks for the input so far. Is there a noticeable effect on exhaust tone from the diameter of the pipe used? I know a 235 doesn't need dual 2.5" exhausts, but will that make the exhaust lower pitched vs 2" pipes? I wish there was a sure fire way to make this thing sound like my Cummins lol.

When I had a modified L-6.I had various mufflers on it.I found the the ones that the local police and I were satisfied with were for for a Big Block Chevelle.I think they were 2".Mufflers shops should list something similar

Yup, that is what I used and they sound great. I picked up a set from a local muffler shop for $20.00 a piece. The shop even fiixed the ends where they would slide over my exhaust pipes. They have a low deep sound to them. I put the cherry bombs on a replica car that was a covertible, bad mistake. The darn things were to high pitched. You couldn't hear the radio over them.

I plan on stock grandma mufflers. That way I can hear my I tunes.

Does anyone (besides Jerry) know where the term "Turbo Mufflers" originated and what car they were used on? Hint: think of turbo charged and arachnid. Very revolutionary at the time since the exhaust went through the baffling under normal use but bypassed when under high demand. A must to keep power killing back pressure away from the turbo. Quiet as a stocker till the loud pedal was floored.

I know.

I'm with you on that one. I'll be switching to stock or at least a set of turbos when I install a new set of exhaust. The old flow masters on it now sound good, but the older I get I feel the need to tone things down a bit.

Right Robbert! I hear way too much regret over installing muffs that are too loud. I don't remember anyone complaining that their muffs are too quiet. Maybe I'm wrong; if I am, someone speak up and let us know how you installed granny muffs and regretted it.
Those barnbangers sound a lot better on someone else's vehicle as you watch it running down the street than when you're in the vehicle yourself. IMO

One approach is to use a BIG muffler with a quiet tone for good exhaust flow without all the noise. I like to use mid-1970's Cadillac mufflers. They are made with 2 1/2" pipes in and out, and one of them is rated to flow enough volume for a 500 cubic inch engine. Dual exhausts on a stovebolt engine with those mufflers would flow like big straight pipes, and be extra-quiet.
Jerry

Jerry,
I am planning on a stainless exhaust system next month and wonder how those Big Caddy mufflers with the 2.5" pipes will fit under my 51. 350 engine/700R4/10bolt/rear swaybar.

The only problem I came across, which really wasn't to much of a problem. Was where the pipes came under the tranny mount. I used the universal tube type crossmember, the type you cut to fit and mounts lay on the top of the lower frame rail. I used 2 1/4" pipe and it was very close to touching the bottom of the cross member. I ended up with almost 1" clearance. The rest of the pipes and muffler had pleaty of room until where I had it come over the rear axle, it is a 12 bolt rear end not the original rear end. I mounted a universal 16 gallon tank beyween the frame rails at the back and the pipes have about 1 3/4" clearance from the tank front lower corner. I tried dumping my exhaust ends down in front of the rear axle. That was a bad idea, cleaned the garage floor real good though.

Laughing, I have the same problem on the Garage floor.

The clearances will be close, depending on what else is mounted under there- - - -gas tank, spare tire, etc. Unless you're determined to have the low rider look with the frame almost dragging the ground, hanging the pipes flush with the bottom of the frame rails or slightly below will solve a lot of problems.
Jerry

Purple Hornies, hands down

Thanks for the heads up Jerry. The pipes are even with the frame rails. And the truck is pretty much stock as far as the frame and stance goes. The front brakes have been converted to 11" disc brakes. I didn't lower the truck any. I'm trying to keep the outside look of the truck original. The spare tire will be mounted on the outside of the bed.

I have fenton headers with flowmasters running ou the back.Those 6bangers have a sound all their own!:)

I have fentons and 2 inch pipe all the way out the back bumper. The mufflers are cherry bomb turbo mufflers,It's not loud or offensive at normal driving, on the highway you can here the radio. That having been said, when I run the rpms up, people want to know what is under the hood," I've never heard anything like that before." Around here everything has a small block in it.

I have the beautiful stainless steel dual-exhaust, "double wide" muffler made by Patrick's. It is way too loud inside the Suburban. I hope to change them back to stock-style straight-through side-baffled mufflers (JC has a new product that nicely matches original mufflers - 15% off at this time).

For those of you that like noisy mufflers (to spoil the neighbor's day and to stroke your egos), I used to have dual stock-design mufflers and the inside of the Suburban was very quiet. With this set-up, I was stopped a few years ago for speeding by a young, local, police officer. I had not yet connected the speedometer cable, so I had no idea how fast I was going. The police officer said I was doing 55+ in a 40 zone (he was not going to write-up 60+ because if would have been reckless driving). I asked him if he would clearly put that on the ticket (to impress my friends).

At the end of our discussion, he said that I was so polite that he felt bad giving me the ticket. But, he added that he had to process it - he had called in for assistance because he heard my exhausts and was afraid I would run him. I again asked if he would please write that clearly on the ticket.

I think the placement of the mufflers has a lot to do with the noise level on a split six exhaust system. I had glaspacs installed on my burb with Fentons close to the bend with long pipes after them. It was obnoxious. Sounded like a cropduster on the highway. I added another set near the end of the run and it is now mellow sounding. I think the aft set is really all I needed.