Took my coupe for a run to town for a wash and a few other errands today. Mildly warmed up 355 SBC. My trans is due at the transmission shop Sunday night because lock up is out on the 700r4. My trans guy said it won't hurt anything to drive it in 3rd gear (1:1 w/3.89 rear gears). So it sings along pretty good without the overdrive. That makes it a few hundred RPM difference and really hits the "drone" area of the mufflers. I can't hear shit anymore, but that drone hurts my ears. It is a dual 2-1/2" system end to end. 4"diameter x 24" long Cherry Bombs that have slowly lost all their stuffing after about 6 years and 25K miles. I would like it a lot quieter than those Cherry Bombs were new when I built it, now however. I would like something OEM quiet or maybe just a tad louder. The problem is limited space to run anything but a center inlet/center outlet muffler. So pretty much a straight through muffler, which are not really known for being quiet. What are my best options for a nice quiet exhaust? Reading reviews and listening to youtube videos, it seems like Magnaflow, Flowmaster or Dynamax don't have anything quiet enough in a straight thru muffler. I have been looking at Patriot Smithy mufflers. They have a 41" long round muffler. The longest I could find. I assume that the longer the muffler the quieter it should be, correct? I'd have to do a little rearranging to get them in there but not too bad. I know some of you guys like the old school Smithy mufflers. Anybody have any experience with these long mufflers?
these are nice and quiet....and if you have room for a 41" muffler, you have room for an offset pipe to get to the non-centered end. But it might be too wide to fit in the space available. https://www.summitracing.com/parts/wlk-17197 good luck in your search. I had cherry bombs on this before switching over to the quiet ones.
I'm using Porters on my Model A. They aren't too loud, but I wouldn't say they are real quiet like a stock muffler. I don't get that droning noise with the Porters.
I just don't have room for that one because of the inlet being offset. If the inlet was centered and the outlet offset, I think I could make it work. Thanks for the idea though. I'll have to do some more searching for center inlet/offset outlet mufflers.
I’ve used Flowmaster Hushpower II mufflers on two cars. Nice sound, not too loud and never any drone. Center in - center out. Comes in two lengths.
Yeah, that drone in the cabin is what I need to get rid of. My mufflers are located directly under the cabin area. They are about 8" below floor level though. My exhaust system is mounted solid to the chassis. Probably contributing to the drone. When I install new mufflers I am going to change rubber mounted hangers. That should help some, but new mufflers should help a lot. I have never messed with resonators. Not sure what they do. Would a resonator directly after the muffler quiet it down or just change the sound?
I have Hush Thrush Turbo mufflers on my coupe. They are pretty short, so accommodating the offset is pretty easy. My coupe is quite. Gene
I have the long Smithy's on my Buick Straight Eight, dual 2" all the way past the bumper. No drone. Ben
This is when you wish for paper catalogs with pictures and dimensions. This one is 2-1/2 in and out with a 19 inch long 4-1/4 thick by 9-3/4 wide with a total length of 23 inches designed for a Cadillac 472 or 500 so a pair of them will flow a 350 pretty good. It just depends on if you have that much wiggle room Walker Exhaust 21856 Walker Quiet-Flow 3 Mufflers | Summit Racing
A crossover, or ''H'' pipe in the system can cut exhaust noise. Also improves low end torque, don't know if you could tell though. Hope you get it worked out.
Hello, Be careful if you decide on Magnaflow Mufflers. Normally, Magnaflow mufflers are top notch and have a good reputation. But, the recent comments about the backfiring, popping sound is not too cool for any hot rod, unless you are one of those that ruins car show or public display of cars. Our neighbor sold his cool M3 and that had wonderful powerful stock sounds on acceleration and when he came to a stop, nothing happened. But, these days, for some oddball reason, he got rid of the M3 and got a new Mustang with mufflers that sounds loud and when he lets off of the gas pedal, the popping starts right away. I heard him accelerate down the street and when the shift hit, the popping sound came into play, between shifts. Jnaki It is your car and sound choice, but Mustangs give cool cars a bad name from quite some time ago... "idiot in a Mustang..." ruining old So Cal Cars and Coffee events and neighborhood car shows. Now, it is a laughing matter when any Mustang is seen. At least try and hear the mufflers you want and make sure the popping sound does not come into play. YRMV
Thanks for the suggestion, but that muffler is listed as offset inlet and is not reversible. An offset inlet moves the muffler out of line to the side from where the muffler exists now. This will put the muffler in interference with the driveshaft or the frame rail depending on which way the offset is installed. I haven't had time to do any more research, but what I need is a centered inlet. This will keep the muffler in roughly the same place as the cherry bombs. I can deal with the offset at the outlet end, just not at the inlet end. Not sure if a center inlet/offset outlet muffler even exists. More research required.
Get on Summit's site and check out the Walker Turbo mufflers. They come in all configurations and likely there is one that will fit right up where your old ones are. They have a good note but are much quieter than the loud, rumbling mufflers some prefer. Like you, I have lost a good bit of hearing and loud mufflers just aren't pleasing to my ears any more, especially on a long drive.
Did you search for S bend pipes? if there's enough room to move the mufflers back a bit, you can put an offset pipe in front of an offset inlet muffler, and make it work.
I run turbo mufflers on my OT trucks , they're back under the bed & still drone .... The chambered mufflers have that tin can sound ...
Can you share an Undercar shot of yours? I can show you how we fit good ones on my father in law's 32. We used 18" long XLERATORS from AP/Goerlich.
I checked out the Dynomax Super Turbo mufflers. They do have a center inlet/ offset outlet muffler, #17748. The case is 9-3/4" x 4-1/4" x 20" x 25.5" overall. I can make that work. $78 each @ Summit, $51 each @ Amazon. I'm tired of researching mufflers, so I think I will order a set of these. If they are still too loud, I'll put a set of resonators on it. As I said, the car is going to the trans shop so it will be a bit before I can put the new mufflers on it. I'll let you know how they turn out. Thanks for your help, guys.
It's been said a few times already, but Flowmaster HP2s are what you want. They will fit anywhere a cherry bomb can and are much more mellow. Get the longer ones, 16" I think. I have them on my warmed up 352 with no H pipe and they sound amazing.
I have found incorrect timing for rpm you are running at or no vacuum advance can add to the drone or correct it.
I have one on the 6-powered Falcon. I don't know what it sounds like alone, as I built the system with a resonator by the back bumper, and had it fully installed before ever firing the engine. It sounds good for a six, and is easy to drive long distances while listening to the radio.
I’ve had dynomax super turbos on cars in the past, I’ve never found them to be loud, they have a nice sound.
Something the OEM do with dual exhaust is mount the mufflers in different locations on each side. The distance from engine to muffler, and length of tail pipe is different from one side to the other about 8" or 10". This helps reduce drone as each side resonates at a different rpm.
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