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Advice on Muffler Sound

66 Sat

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I need some advice on muffler sound. The issue I have is the car sounds great at idle and at cruise, great from about 3000 rpm to 5,500 rpm, but if I nail it at low revs the exhaust sounds really "farty". It's a loud, "open" type noise, not a tight sound like at higher revs. The mufflers are a generic type from the local muffler shop, no brand. The engine is a 318 poly, bored to 328, 10:1 compression, fairly hot solid cam, 4 barrel intake, factory exhaust manifold, 2.5" pipe size I think, no H or X pipe, auto, 3.23 rear, standard converter. Any suggestions on mufflers that are reasonably quiet, but will give a nice tight note throughout the rev range, or is it more likely a result of the engine specs (cam etc)?
 
Dyno-Max sound really good. I use them over others because they don't have that tinny sound. The cam duration notes really shine through these systems.
 
I had Magnaflows and really liked the sound. The ones I have now are Cherry Bombs! I like them too.
 
Go to local cars shows and meets and listen to what rolls in. Then ask them what there running and etc....
 
There are three basic types of muffler, triple pass (turbo, majority of oem) staight thru with glass packing, and chambered type( flowmaster and copies). You likely have triple pass. The larger/longer case will be quieter.
Rumblefishes advice is excellent, find out which style has the sound you like, then start shopping that type .
I personally like the flowmaster sound, tho some have trouble with droning, and some say they are horsepower killers. I'm willing to give up a few horsepower ( maybe five?) for the sound i want.
I have used the 5series flowmasters on my dually and my 62 (BIG truck mufflers) and hooker aero chambers, and magnaflow straight thru. I liked all of them, preferred the flowmasters.
And yes, your particular combo will affect how any muffler sounds. A 150hp will sound different than a 800hp combo thru the same muffler.
 
There are three basic types of muffler, triple pass (turbo, majority of oem) staight thru with glass packing, and chambered type( flowmaster and copies). You likely have triple pass. The larger/longer case will be quieter.
Rumblefishes advice is excellent, find out which style has the sound you like, then start shopping that type .
I personally like the flowmaster sound, tho some have trouble with droning, and some say they are horsepower killers. I'm willing to give up a few horsepower ( maybe five?) for the sound i want.
I have used the 5series flowmasters on my dually and my 62 (BIG truck mufflers) and hooker aero chambers, and magnaflow straight thru. I liked all of them, preferred the flowmasters.
And yes, your particular combo will affect how any muffler sounds. A 150hp will sound different than a 800hp combo thru the same muffler.
Thanks for the info on the different types, very helpful. The biggest issue I have is that I actually like the sound of the mufflers I have most of the time. It's only that specific circumstance, bootful of throttle at say 1500 rpm in second or third. If I launch hard in Drive or if it's held in First, then the revs rise quickly through that range and it sounds good, but if it's more torque doing the work then the mufflers seem to give up - it's hard to describe but it's like they let the air out too quickly, like there's a blown baffle or something. I'll have to keep researching - I used to have Cherry Bombs on my Barracuda and that sounded great, but I was also 23 so the louder the better. Now I'm after a more cultured sound. I did like the sound of Frank Bullitt's Mustang but I think that was overdubbed with a Nascar.
 
I don't care what brand it is as long as it's well built (welded not crimped) and continues the same I.D. all the way through with small perforated holes. I really love the sound of a chambered muffler too but the resonance can drive you mad!
 
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An x pipealmost has to be part of a system from the beginning, but a h-pipe might be an easy modification that could mellow out the sound you dont care for. I would incorporate a flange of some sort,to enable disassembly for trans or driveshaft access. Sure won't hurt, even if you decide to change mufflers later.
 
A lot of good advice here. The 40 series Flowmaster is loud and is the muffler usually associated with FM, but the 50 series and 70 series maintains the FM bass tones but at a much lower decibel level and without drone. Can't beat Dynomax Super Turbo's either. Check out some sound clips here- https://classicmusclecarexhaust.com/
 
I picked the Welded Ultra Flo as shown in the chart below. I had Flowmasters on the car and did enjoy the sound for awhile. At one point I thought I'd try something different so I looked for a better flowing muffler and stumbled upon this chart.
Mine are not quiet but they are quieter than the Flowmasters at every point.
Muffler flow rates.jpg
 
First, you'd be surprised how much tips can change the sound. That may be an easy place to start. Second, you could always copy the factory method of adding a resonator after the rear axle - a pair of short cherry bomb style mufflers would work fine, in addition to your current mufflers.
 
Thanks for all the advice guys. There's a big show coming up next month, I'll be listening to all the cars and asking a lot of questions!
 
always liked the original HEMI style muffler when they get some age I think they sound good
 
I have 1-3/4 Heddman Headers, 3" pipes, and Summit Turbo Mufflers (SUM-633230), but at 88db from 20 inches @750 rpm, they were a bit much. So I added Summit Racing 18" glasspacks (part number SUM-630810 ) which dropped the sound level to 83db. As an extra bonus, the neighbors four houses down no longer complain about rattling the windows and scaring dogs when I crank it up.

I get a lot compliments on how my exhaust sounds; more than anything I've ever driven. Do you know how some mufflers changes the note of the exhaust? For example Flow Master, Magnaflow, and Borla has that distinct sound no matter what engine you put them on? You're paying for someone to engineer that sound.

The Summit racing mufflers doesn't change the sound of the exhaust. It just quieten the exhaust. The end result is a more natural sound. Seriously, a few weeks ago I ran the car with open headers, mid pipes without mufflers, with mufflers, and with muffler+glasspacks. It all sounded the same, just less noise as more pieces were added. Just my two cents.
 
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