Mach 1 Exhaust Pipe Sizes

[Zelek]

So I have some 1-7/8" Kooks green catted headers on order and I'm looking to eliminate the bottleneck of the OEM connection to the resonator. So I'm starting with the 3" Kooks adapters

https://kooksheaders.com/exhaust/co...-connection-adapters-2015-2020-mustang-gt-50l

The next plan is to get the Stainless Bros 3" dual in/out straight through muffler/resonator:

https://www.stainlessbros.com/3-dualdual-ss304-thin-oval-muffler-17-oal--polished.html

After that, I have a few options here. I could get some 3" pipes fabricated and then reduced further down the exhaust stream to the stock pipes or reduce it at the 3" outlet side and have it welded there. I'm guessing the first option will probably be a bit more expensive.

I guess my question is what is the exhaust piping size behind the resonator? Is it 2.5" like a standard GT or is it 2.75" like a GT500?

Sponsored

 

[Coastal-Mach]

https://www.mustang6g.com/forums/threads/exhaust-pressure-testing.162791/

@Zelek check this thread, EngineerMike did a whole write up on changing exhaust components.

 

[Zelek]

https://www.mustang6g.com/forums/threads/exhaust-pressure-testing.162791/

@Zelek check this thread, EngineerMike did a whole write up on changing exhaust components.

Yeah, I read through about 98% of that thread. That's how I got info on Stainless Bros and also found out they are just down the road from me. One of the few true straight through designs.

 

[WCRookie99]

Kooks 1-7/8 fit perfectly see my post:

https://www.mustang6g.com/forums/threads/if-buying-long-tubes-what-or-who’s-fit-the-best.175561/post-3553016

 

[Atlas1]

Kooks 1-7/8 fit perfectly see my post:

https://www.mustang6g.com/forums/threads/if-buying-long-tubes-what-or-who’s-fit-the-best.175561/post-3553016

What did you do to get rid of the check engine light?

 

[WCRookie99]

What did you do to get rid of the check engine light?

its not on? Both O2 sensors are installed on each side and I was able to not use the harness extensions.

Now I only have two miles of testing on it and a Lund tune, maybe that’s why, I’ll let you know after I drive it some miles on the track.

 

[Atlas1]

its not on? Both O2 sensors are installed on each side and I was able to not use the harness extensions.

Now I only have two miles of testing on it and a Lund tune, maybe that’s why, I’ll let you know after I drive it some miles on the track.

I can’t wait to hear it rip on track! You’re running stock tune right? Going to leave that alone or adjust for headers?

 

[Zelek]

I can’t wait to hear it rip on track! You’re running stock tune right? Going to leave that alone or adjust for headers?

Looks like he's on Lund. I wouldn't expect the stock tune to adjust to the full potential of adding the headers on. The CEL will usually come on if you're cruising on a highway at the same speed. Just run a couple spacers on the secondary O2's and you'll be fine if that does happen.

 

[Zelek]

Kooks 1-7/8 fit perfectly see my post:

https://www.mustang6g.com/forums/threads/if-buying-long-tubes-what-or-who’s-fit-the-best.175561/post-3553016

I see you did a Kooks X-pipe. Are you running an aftermarket axle back or did you keep your Mach 1 axle back?

Did you need reducers behind the X-Pipe if you connected to the stock pipes?

 

[WCRookie99]

So I had Lund tune to 100oct racing fuel only with LTHs as I’m only using this car for Track days. They say it’s different then their 93 Tune but didn’t say how or elaborate in any way.

Actually when reading up on the entire racing fuel difference vs pump gas, obviously the octane is higher but it’s just more pure and cleaner.

Plus, the tune is simple to convert back to stock tune in 5min or so.

I purchased Kooks axle back Muffler with 4” tips which are actually engineered to bolt the Factory Bypass actuator on them so it avoids any dashboard light or programming issues. So it 3” all the way no reduction in pipe.

if you wanted to keep the stock Axle back, Muffler and Tips, yes a 3” to 2-1/2” reducers behind the X-pipe would be needed but I don’t believe Kooks offers it standard, it would be a custom piece. (shouldn’t be that hard to fabricate)

Final comment about running spacers on the secondary O2’s. I actually did that because I didn’t like the fitting of the O2s in the Kooks pipe, so I put them in by dumb luck.

So a lot of additive reasons as to no Check Engine light.

Sponsored