Quiet my 2015 GT on the cheap

gsrblack

New Member
Feb 11, 2025
5
0
1
AZ
Just picked up my 1st Mustang a few weeks ago. Realized after buying it that it is way louder than I thought after driving it back to my suburban neighborhood. I did get it at a good price and always wanted one but my test drive was very limited and it sounded great in an open parking lot. Didn't get to test drive it in a freeway so didn't know how bad it droned and how loud it was in the cabin. Anyways, just thinking how I can rent the sound on the cheap and wanted to get anybody's thoughts. I may just keep it a little and sell it or trade it for more of a stock GT (also premium, PP and 6MT).

The seller replaced the entire exhaust...LTH, cat delete, resonator delete with H-pipe and MBRP cat back exhaust and swapped in Flowmaster Outlaws mufflers instead of the MBRP mufflers (he wanted a different sound after driving on the MBRP mufflers for a time). Car is on a 91 tune.

I'm debating if adding the stock resonator (which I have) back in would quiet the car down much and lessen the drone inside the cabin while cruising. The stock resonator will need fittings to neck down from 3" system on LTH to the stock 2.5" and then back to 3" for the exhaust.

Local muffler shop wants around $300-$400 to cut into H-pipe to swap it out and make the correct fittings. I worry that it won't do much and whether or not I'd have to get the car tuned again.
 
It's a very deep growl ... Would be fine if on a track.

Just don't know enough if spending the money to put the stock resonator in place of the h-pipe would be a waste and not buy me much for now and drone reduction.
 
I used to have the most obnoxious exhaust system in the world on my Procharged 20GT. My wife refused to even get in the car. The cold starts would blow the pictures off my garage walls. I had to change it all up.

So my car now has Stainless Works Long Tube headers / no cats / stock resonator / stock catback and still made 800hp at the wheels. You don't need a loud exhaust to make power. In fact the long tubes and cat area is where the power is made. The rest is just noise.

I had this:


View: https://flic.kr/p/2q1RYXh


I now have this:


View: https://flic.kr/p/2oAwH72

View: https://flic.kr/p/2oAwH72
Cold Start and Idle Here:


View: https://youtu.be/xeYPSd96Vf8?si=VHzFMpC7zB1vVtUG
 
  • Like
Reactions: 89ripper