The Borla mid-pipe replaces the factory resonators with straight, mandrel bent pipes. The weight difference between the original mild steel exhaust and the new 304 stainless steel is pretty substantial.
The Borla S-Type muffler weighs in at 11 lbs, exactly half the weight of the factory muffler. That’s a 22lb weight reduction off the rear of the car from just the mufflers, not including the weight reduction from the X-pipe and center section.
The quality of the stainless steel Borla muffler is significantly better than stock. This would be the only component to replace on Borla’s Axle-Back exhaust system.
The Borla Cat-Back exhaust system includes two heat sleeves for the EVAP system.
Protecting these lines from excessive heat will make sure we don’t run into reliability problems later down the road.
After hanging the muffler, we were able to uncover and expose the beautiful black chrome exhaust tip.
Quick Reference:
Page 1 – Stock Exhaust & Borla S-Type
Page 2 – Stock Exhaust Analysis
Page 3 – Crossover Pipe Removal vs Borla
Page 4 – Mid Pipe & Muffler Removal vs Borla
Page 5 – Borla Installation
Page 6 – Borla Installed
Page 7 – Dyno Borla & K&N Airbox Lid On vs Off
Page 8 – Dyno JLT vs K&N Intake. New PBD Tune Dyno
Page 9 – Dyno Overlays: Stock, Tuned Stock Intake Manifold, 2016 Mustang, 2018 Mustang, 2012 Boss 302, Conclusion
14 comments
Great write up with usable comparisons. Do race mustangs tend to stick with duals or go to single for weight?
The old FR500Cs had dual throttle bodies, but most Mustangs now use single round TBs for simplicity.
Really enjoy your perspective on so many things and this build is enjoyable to follow.
Page three, second paragraph first sentence says intake manifold, but probably meant exhaust manifold.
You got me, I got you 😉
Thanks for the feedback!
Thanks for the articles! Stay safe.
Very timely article for me, as I’ve been looking at 11-14 GTs as a fair weather DD, and part time track car. My brother has 12 Boss, but a TP/Brembo GT fits my needs and budget. Is there a Part 1 posted somewhere?
Thanks for posting. Looking forward to Part 4…
what was the alleged speed for the intake on road lid on test? and what gear?
I used nothing but Borla Exhaust on all the BDX Mustangs we made from 2007 to 2009. Love it. Trivia, in 1988 my Fox was the mule for the 1st Mustang Borla system. Alex borrowed it and I drove his T-bird for about 2 weeks.
That’s really cool historical fact! I have Borla on my Tundra tow vehicle, nice mellow V8 rumble in Touring spec. And got an S-Type coming for my Turbo 4 Camaro 1LE, which needs an exhaust note desperately.
Great information, I own a 2014 GT Mustang that I track 3 to 4 times a year, I have done some suspension and brake mods but no engine mods yet.
Really appreciate how methodical and well thought out all your articles are Billy!
Looking forward to seeing the continued progression of this car. Are you planning to road test the airbox lid comparison as described on Page 7?
Factory exhaust is 409ss not mild steel. Pretty much every factory exhaust since the 90s is 409ss. You will find steel components like flanges and hangers, but piping and mufflers are 409ss. Some later stuff is aluminized coated 409ss like the back half of Mopar exhausts, pickup truck tailpipes, generally anything somewhat visible from the outside of the vehicle.
Long tube headers, albeit expensive, will indeed provide for a substantial increase in RWHP….and RWTQ. You would be up to 450 rwhp with LT’s….and that is a bunch. But that would require either no cats..and an X….or a hi-flow catted X. Then the appropriate mufflers, to tame the noise/any drone. Resonators, just before the rear axle, would also tame noise down, if the mufflers didn’t do the job.
We didn’t want the car to be obnoxiously loud, which long tube headers often do. The car is already borderline with cats and the quietest muffler Borla makes. We are happy with the sound and performance with the current package, meeting our performance goals.