The Mustang Forum for Track & Racing Enthusiasts

Taking your Mustang to an open track/HPDE event for the first time? Do you race competitively? This forum is for you! Log in to remove most ads.

  • Welcome to the Ford Mustang forum built for owners of the Mustang GT350, BOSS 302, GT500, and all other S550, S197, SN95, Fox Body and older Mustangs set up for open track days, road racing, and/or autocross. Join our forum, interact with others, share your build, and help us strengthen this community!

GT500 Exhaust - Heads Up

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

519
16
I installed the Ford Racing GT500 cat back system a few months ago, but had not put a lot of time on them, maybe 300 miles of easy street driving.

I did a track day yesterday at High Plains, and when I finished the first session, which I did not run that hard (engine temp was around 220F), when I returned to the pits I idled for a few minutes and shut off the car. After 20 seconds or so, smoke started coming out of both tailpipes, and it smelled like burning plastic. We realized it must have been the muffler packing burning off!

Anyone else ever see this?
 
when mufflers are brand new yes they can smell and smoke.

I installed new GT500 OEM mufflers (2013 quad tips) and although I never ran the car hard, they smelled for a week or so. This is the exact same on all my other car builds. I was surprised at how long it took to burn off on these, normally it's only a few hours but it's to be expected and is normal.
 
Did you check out the stone guards near the side exhaust? I melted mine my first track day, had to trim off the bad parts, now it blows by it.
 
519
16
racered302 said:
Did you check out the stone guards near the side exhaust? I melted mine my first track day, had to trim off the bad parts, now it blows by it.

The smoke was clearly coming out of the rear pipes, on both sides.
 
The smoke could easily be water vapor, and the smell could be the oil residue left from the pipe bending process or to prevent rust during storage.

If your side pipes were open during your track event, there is a very high chance you melted the little louvers in front of the rear wheels. Double check either way.
 
coboss said:
The smoke was clearly coming out of the rear pipes, on both sides.

The plastic smell is what I was talking about, that's why I mentioned the stone guards. As for the smoke coming out of the exhaust I'm not sure. I have the same axlebacks but hadn't noticed or smelled any thing from normal driving after I installed them.
 

TMO Supporting Vendors

Top