I've heard different answers from different people. Some say the entire stock exhaust is 2.5", while others say the catback part of it is 2.5" with the H-pipe being 2.25". I can't remember where, but I read an advertisements on a mustang performance parts website where they say, "upgrade your stock 2.75" exhaust to a 3 ". Does anyone know the correct size of the stock exhaust?
What is the size of the stock exhaust on the 13-14 GT?
- Thread starter Benson5oh
- Start date
2-3/4 on the catback but the H pipe does neck down between the joints to 2-1/4. If you're lowered 9 times out of 10 you will have issues with a 3 inch catback hitting the rearend on bumps.
Also the resonators on the factory catback neck down to 2-1/8
Also the resonators on the factory catback neck down to 2-1/8
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^This.
The pipes narrow down in several spots, and a couple of the stock bends look like they were stamped with a brick. Huge flat areas.
Even before I lowered my car, my 3 inch Over Axle Pipes would hit a nipple on the axle that I believe is a relief valve. I have a nice stamp in the OAP about the size of a pen. I took it to a local muffler shop and the guy did some cutting, bending, and welding to clear that little nipple and now even with the car lowered I no longer bump the exhaust on the axle, but the H pipe itself bulges and hangs a little low and I have a steep narrow driveway so the H pipe scraped where the driveway meets the sidewalk until I added speed bumps at the bottom of the driveway.
3 inch exhaust = headache. I suspect the nicer kits have better fitment and tuck closer to the body, my experience is with a Heartthrob kit that I picked up open box for like $230. Dirt cheap, so I was expecting to run into issues. Despite the headache, I think the 3 inch cat-thru-axle kit is an improvement over stock. I'm sure 2.75 pipes would be just as good, just anything that gets rid of the sharp angles and inconsistent diameter in the stock piping. In the end, it's still most likely going through a 2.75inch muffler.
The stock catback is 2.75" The h pipe does neck down as stated above. I did not have any issues with rubbing with my 3" catback.
Paul,
Were those photos taken from a 13-14 GT? Well it's definitely narrower in many odd places throughout the exhaust.
Thank you guys for giving me the correct size. Obviously, I want to upgrade my stock exhaust very soon, preferably with a catback, x-pipe and shorty headers, but the question is, I'm not sure if I should just go with the 2.75 inch or 3 inch. Not that it's going to make a difference powerwise, but I don't want to regret it later. Right now, I believe Borla is the only aftermarket company that makes a 2.75" catback version of the touring, s-type and atak, at least for the 13-14 GT. With this system I can add a 2.75" x-pipe and make everything even all the way across. Every other company such as Flowmaster, Magnaflow, and Bassani only offer 3 inch catbacks, so you don't have a choice with them. Right now, I'm just undecided.
Were those photos taken from a 13-14 GT? Well it's definitely narrower in many odd places throughout the exhaust.
Thank you guys for giving me the correct size. Obviously, I want to upgrade my stock exhaust very soon, preferably with a catback, x-pipe and shorty headers, but the question is, I'm not sure if I should just go with the 2.75 inch or 3 inch. Not that it's going to make a difference powerwise, but I don't want to regret it later. Right now, I believe Borla is the only aftermarket company that makes a 2.75" catback version of the touring, s-type and atak, at least for the 13-14 GT. With this system I can add a 2.75" x-pipe and make everything even all the way across. Every other company such as Flowmaster, Magnaflow, and Bassani only offer 3 inch catbacks, so you don't have a choice with them. Right now, I'm just undecided.
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Here's the over-axle pipes off a 14, see the brick shaped stamping at the bend and on the resonators? no bueno. Resonators aren't needed with a high quality muffler anyway. Sounds much better without them.
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I think the top set with the cats attached is from a 15+ and the bottom one is from a 11-14
I had longtubes on a 02 GT. Those things use to scrape all the time, with speed bumps, dips, driveways, etc. My car was lowered 1.5", which may have contributed, but it was annoying. I really want the shorty's more for the looks than anything else.
No scraping here, but I understand your concerns.
If your reasoning for getting short headers over long tubes is clearance, I think I'd stick to 2.75 inch. I'm pretty sure the 3 inch is only better near WOT anyway.
My car is lowered on eibach prokit 1" front 1.5" rear. Kooks mid length headers jegs 3" header back. The OAP need to be adjusted I don't hit those anymore
Not sure why everyone says a lowered car with 3" exhaust will rub. you only have to take some time and minor adjusting.
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