Best Mufflers

[tony-muscle]

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.

I have never checked the fuel delivery but I could.

 

[71466Mach]

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 geI t?

I think the Hooker Aero Chambers are absolutely fantastic, but as Hemikiller pointed out probably not for everyone. I have 3" ACs on my 71 (BBF) and 2.5" ACs on my 69 (351C-4V). On the 71 I went with Magnaflows, not sure exactly which, but they sounded way too tame to me. In my experience the ACs are loud/aggressive @ high rpm, but much quieter at cruising speed, especially in 4th and 5th on the 69. Right now the 71 is an auto w/ 3.89, so louder all the time.

 

[mach71351c]

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

Tony, google Kindig-it Design exhaust cut outs.

 

[mrgmhale]

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.

I had more drone at highway speeds than I wanted. It would get on my nerves after about 20 minutes of drirving. It remained even after switching to a set of mufflers with more backpressure (and the normal operating temperature of the engine increased by about 2 degrees F). I then decided to have an x-pipe made with some fairly radical bends to help the sound waves a lot of metal sidewall to "crash into" to help the metal tubing absorb and reduce the droning. It was a hail Mary, and the potential from increased back pressure due to the fairly radical turns were not a concern as I am not racing the Mustang competitively.

Anyway, the X-Pipe, even with its radical turns, did the trick. The Mach 1 is now a pleasure to drive, and the exhaust sound is still plenty hearty. I also noticed the normal operating temperature of the engine is back to where it was with the higher flow mufflers, so giving the exhaust gas two escape routes apparently did relieve the back pressure enough to offset the snake like turns the X-Pipe introduced - a pretty good indication that I did not cause additional restriction overall.

 

[giantpune]

For quiet, I like the no-name turbo mufflers.

If you want the flowmaster sound, you can get that for half the price. My local midas exhaust guy uses some clone brand and swears by them. It was still more than the $40 summitracing race mufflers I had him install. I'm not recommending those in this situation, cause they're probably a tad louder than OP wanted.