Brewster

Thinking of first upgrade, a new muffler. I would like a deeper sound, no drone, not too loud. I dont want it just for sound, but if a muffler will provide any power increase and/or gas mileage then I will do it.

Which single would be best for my wants and have you seen any power or mileage increase with your single exhaust upgrades ?

richp

From what I've been reading, either the Flowmaster AT or for much less $a GT take off mufler work well. Some like the MRT muffler, some don't like it's sound as much though. Also, if you stay with the singe exhaust, the drone won't happen.

You won't get any noticeable change in gas mileage but you'll sound cooler
I read a report from a guy that has his own dyno machine. With the CAI he saw 5 rwhp improvement, then adding the GT or Flowmaster AT muffler gave another 10 rwhp. Not sure if you'll get 10 rwhp increase with just the muffler alone though.
This guy also said that adding the JBA headers did not increase hp.

Rupp

I added a single GT take off and love it. I did notice a bit of performance gain and love the sound. I can tell you one thing, I wouldn't want it any louder at all so if the MRT is any louder I wouldn't have it.

raubt

You've got lots of options. Just search the forums for "single exhaust" or "single muffler" or whatever and you'll find lots of stuff to help you make your decision. Check out pictures and sound clips and just go with what you like. MRT, Flowmaster, SLPs, GT take-offs, on and on. They all have different looks and sounds to them, so give the boards a search and you should be able to come to a conclusion about what you like and what you don't like.

Personally, I ordered a Flowmaster AT single muffler a few weeks ago, but it won't be here for a little while so I don't really have any first-hand experience to back it up right now. All I know is the Flowmaster sounds pretty coarse and throaty, whereas the MRT is more race-car sounding (smoother might be the better word) when it revs. But they're all loud, and they all have sweet looking chrome tips, so it's really just a matter of personal preference and what you think will fit your Mustang the best.

mustangman02232

MRT

Rnstanger

Sounds like you want a GT take off muffler. I thought the Flowmaster would be pretty tame but people who hear my car say otherwise. My daughter and I were driving home from the store and she said "Daddy, everybody is looking at your car". Then she proceded to demonstrate their facial looks which had me rolling so bad I almost had to pull over. I attributed it to the Flowmaster.

wolfey2k

I recently read that the JBA single is a pretty good overall choice performance and noise wise. Quietest of them all from what I read.

However,,,,,,,,

I would think that simply adding a better flowing muffler to the single exhaust would only produce a minor improvement in overall V.E. (Volumetric Efficiency). That seems to be the case.
The real improvement comes in after one re-programs the MCU with an aftermarket performance program.
Then the better flowing muffler will show it's stuff as it will have much less back pressure when you have your foot in it! ;-).
Just my opinion but I'm soon to find out for myself.

I am also considering purchasing a GT rear bumper cover and converting the exhaust system to true duals. I'll probably weld an X pipe in myself after the cats to keep it emissions legal which I don't mind. I really dont' want a loud exhaust system so I'll stick with the OEM mufflers in any case.
I know that by adding dual exhaust I'll cut the back pressuremore than in half and still keepthe db's down respectfully.

8cd03gro

the backpressure isn't going to change from a tune . you will gain more after tuning, but that is NOT because of a change in back pressure. You get gains from that without tuning.

so far it seems like mrt puts down the biggest gains, but it is very loud. i personally love it, but if you don't want LOUD it is not for you.

wolfey2k

Did you even read my post? Obviously, 'and even a total beginner should realize this', a tune isn't going to change back pressure. Geesh!

birdoffire7

After much research and listening to clips on the net, I went with the MAC and love it. I put mine on with about 2k miles on the car. Honestly, it sounded like crap when I first put it on. I almost took it right back off. I'm not sure if it was due me not unhooking the battery to reset the computer to adjust for the new air flow or because it needed to break in, but at first it sounded like I stuck a ricer coffee can on it. Now after its broken in and/or the computer adjusted, it sounds great. A friend of mine bought the much more expensive Borla for his '05, and when sitting next to each other the MAC is much more throaty and deep. We both agreed mine sounded much better. It does drone a bit around starting at about 70 mph in the cabin, but overall the sound and look is simply awesome. You do hear it inside the car some at almost all speeds, and it roars when on the throttle accelerating - but this is exactly what I wanted. If you are looking for a loud, deep muffler to announce your presence, then get the MAC. If you are looking for something that you won't hear as much, go with something else. I have a Flowmaster on my Firebird (am I allowed to mention that car in this forum? If not, sorry!), and love that sound too. The Flowmaster should sound good on our cars also, but I didn't like the fact that it wasn't stainless steel.