Best Mufflers

Hey all! Im putting a new 2.5" exhaust on my 73 mach 1 with 351c 4v and shorty headers. I know I want an H pipe but my biggest question is what mufflers? I dont want anything obnoxious or not comfortable to drive because we are driving it regulary and going to events. Any advice what to get?

Personally I like the Flowmaster FlowFX I put on my car. I find them "neighborhood friendly" at low rpms, but nice a throaty when I stand on it.
My car runs stock manifolds, 2 1/4" H pipe, FlowFX and custom tailpipes with chrome tips (for staggered shocks)
This car had Flowmaster 40's on it when I got it and the drone was ear splitting. I don't find that with the FX mufflers.
You'll get many opinions, it's like a chocolate donut versus a glazed one.

Everyone will have their own preferences on this topic. I have always found the Dynomax Super Turbo mufflers to have a nice balance between too loud and too quiet. They aren't raspy and they don't drone. They're easy on your ears if you're going to be doing any distance cruising, want to listen to the radio, or carry on a conversation. And they sound good when you get on the throttle.

I used FlowFX also on 2 mustangs.
I also put electric cutouts on mine for when I really want some noise!

I just got my exhaust done. Over the years I used Flowmasters on everything. This time I wanted something on the quiet side. I went with Dynomax Super Turbos and KenDig exhaust cut outs. I'm really happy how it sounds nice and mellow with a bark.

I went with MagnaFlow Performance mufflers, 2.5" in and out with a customer 2.5" exhaust with H pipe and stainless works exhaust tips flared out to 3". I usually prefer a more growly type exhaust and have had good luck with these mufflers on my other cars. As far as I know they are the same mufflers, I bought them at Summit and they list performance and race and I have always just bought the "performance mufflers". They may just be a different model of muffler from MagnaFlow but they were listed the same and appear identical to the mufflers on the other cars. TBH, I can't say I would use these again on this car, and will probably change them out in the future. I have found that this car seems to have a bit more drone at cruising speeds than the my other cars do. I am not sure if it is exhaust design or compression, but my Mustang has 10.5:1 compression and my 69 Camaro has 10.5:1 and my Chevelle is 11:1 so it may be the fact that the Mustang tips head straight out and have some sort of a resonator in them. Also, the other cars have big block Chevy engines, the Chevelle is a 454 and has the factory oval shaped outlets and the Camaro is a 396 and has turn downs that are tucked tight to the rear valence. Maybe it is the Mustang's trumpet type exhaust tips, I am not sure why. It is definitely louder and has a bit of a drone in the cabin, especially at highway type speeds with a load on the engine. I like the idea of the electric dumps like mach71351c did but they weren't in my budget at the time of the exhaust install. Maybe I will have the mufflers swapped to a turbo muffler and add the dumps when I have the car done and some extra money burning a hole in my pocket, haha.

Based on recommendations from this forum, I went with the Dynomax Super Turbos. I put together a system that exited just head of the rear axle with the intent of running out the back at a later time. Last week, I decided to get some prebent tubes on order to finish the job. I spoke to Tom, the owner of Classic Muscle Car Exhaust, and ended up buying the parts from him. He asked me what mufflers I was running and when I told him, he said they were a very good muffler and the best flowing quiet muffler in that class. Very knowledgeable guy and very helpful. PM me if you'd like his number....although I think it's listed on his website.

I have 2.5" Hooker AeroChambers on my 71 and they're coming off over the winter. Not sure if it's just the dynamics of the entire system, or the turndowns by the valance, but it has a horrible resonance @ 2000 rpm. It gets worse after running the car for a while when the exhaust fully heat soaks. Otherwise, they sound great and would probably be fine on another car.

My choices of on hand mufflers are DynoMax UltraFlow, DynoMax Super Turbos and a set of original black painted Flowmasters. I'm probably going to try the UltraFlows first. If it still resonates, then the Super Turbos will go on.

When I bought my car it had Flowmaster 40s and the drone was horrible on the highway. I have since replaced them with DynoMax super turbos and the drone is gone. The car isn’t super loud, but loud enough to know it’s there, especially when I get on it, while still having a nice sound. It has 2v heads, stock manifolds, H pipe, and original style tips. I receive quite a few compliments on how the car sounds, and I am happy with them.

73 SGM Mach said:

Hey all! Im putting a new 2.5" exhaust on my 73 mach 1 with 351c 4v and shorty headers. I know I want an H pipe but my biggest question is what mufflers? I dont want anything obnoxious or not comfortable to drive because we are driving it regulary and going to events. Any advice what to get?

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dynomax ultraflow 14"

I haven’t heard amazing things about flowmaster recently so I kinda don’t look into them anymore. Original plan was to use dynomax super turbos but now I am leaning towards spin tech, not sure what size though. 3inch exhaust but I don’t want to be loud and obnoxious, h pipe as well.

Zach said:

I haven’t heard amazing things about flowmaster recently so I kinda don’t look into them anymore. Original plan was to use dynomax super turbos but now I am leaning towards spin tech, not sure what size though. 3inch exhaust but I don’t want to be loud and obnoxious, h pipe as well.

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There's a video on YouTube,a fox body using spin tech. They are loud and tinny. I think it was the spin tech 9000

I had a good old-fashioned pair of Hush Thrush my grandmother, who was the store manager for the Monkey Wards in Blue Island IL, buy me them waayyyy back when. Monkey Wards is the key how far back.

Yeah, I know, there are much better products available today but even without headers, that 351W sounded awesome with them mounted in the normal spot and just a short tail, down-pipe right before the differential.

Can't remember the name but there was one muffler back in the late '70's I remember was almost a straight through with the offset inlet and outlet. Not Cherry Bomb Glass-packs and not Thrush. They did pass the "pull-over" test with Officer Friendly since there was definitely a muffler there.

As I digress, that was when they also carried a yardstick to show rear vs front height. 3" difference was all that was allowed. I never had a problem because I liked my car oh so slightly off centered for Late night Mall Parking lot slalom. The reasons we would give to have the "go-fast shocks", and "go-fast tires" maxed out. As far as air shocks went, some guys even installed a bleeder valve in the shifter area so they could get legal if pulled over.

Thoughts on Magnaflow turbo mufflers?

73 SGM Mach said:

Thoughts on Magnaflow turbo mufflers?

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They are a deeper sound compared to dynomax ultra.If you going for sound, you can go wrong with either. Performance i picked the dynomax ultraflow. My car has a x pipe 3 inch.

73 SGM Mach said:

Thoughts on Magnaflow turbo mufflers?

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3” X-pipe and 3” hooker max flow is the same style as magnaflow.

Here us idle in my garage with turn downs.

It rattles every glass object in the house.

The best of both worlds is to have a good street mannered muffler like the Dynomax Super Turbos combined with exhaust cutouts. With the cutouts you can make the car as loud as you want for racing, car shows, show off or whatever. When you hit the highway you close them and you can cruise comfortably. I have said combination and made 13 extra horses between muffled and open exhaust with no loss of torque (https://7173mustangs.com/threads/chi-4v-heads-report.45478/). I like the cutouts that @mach71351c shows above. They look lower profile than mine. Mine use a "Y" adapter and because of the flange they end up leaving less ground clearance.

mach71351c said:

I just got my exhaust done. Over the years I used Flowmasters on everything. This time I wanted something on the quiet side. I went with Dynomax Super Turbos and KenDig exhaust cut outs. I'm really happy how it sounds nice and mellow with a bark.

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Can you provide a link to KenDig. I don't seem to find them. I really how low-profile their kit is.

Our 73 Mach 1 with a moderaate street/strip built 351W (not C) came to us with Hooker Long Tube headers and a set of FlowMaster 44s. It was a bit harsh, so I had an x-pipe made and installed. The x-pipe bend are a bit radical as I was hoping any sound waves internally would be absorbed by the piping sidewalls and thus a bit suppressed. I noticed two things immediately. The harsh drone was done while the overall tone was softer feeling. The engine began to run 2 degrees cooler, likely because the hot gas in the exhaust system was able to escape more easily.

https://www.youtube.com/watch?v=pjdO_QOo30o

tony-muscle said:

The best of both worlds is to have a good street mannered muffler like the Dynomax Super Turbos combined with exhaust cutouts. With the cutouts you can make the car as loud as you want for racing, car shows, show off or whatever. When you hit the highway you close them and you can cruise comfortably. I have said combination and made 13 extra horses between muffled and open exhaust with no loss of torque (https://7173mustangs.com/threads/chi-4v-heads-report.45478/). I like the cutouts that @mach71351c shows above. They look lower profile than mine. Mine use a "Y" adapter and because of the flange they end up leaving less ground clearance.

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If memory serves, you're running a TBI system? Does your system log a parameter that would show an increase in fuel delivery to maintain the AFR? I'm curious how much additional fuel is added with the reduced back pressure. I always had to rejet my carb for open headers when I took it to the drag strip.