Lethal Performance 2020 Shelby GT500 Resonator Delete X-pipe: Installation, Sound Clips & Dyno

In 2011, with the introduction of the beloved Coyote 5.0L engine, Ford also introduced a new part of Mustang exhaust systems: resonators. While the folks who appreciate a toned down exhaust note enjoyed having these on their exhaust, most of us want a little more flow and a lot more growl. For the 2011-2014 cars, the resonators were located in the over axle pipes and were easily deleted with a set of Lethal Performance Over Axle Pipes, allowing you to maintain your factory axle back or switch to a number of performance axle backs on the market. You could also opt to do a full catback which would eliminate the resonators as well. 

In 2015, however, Ford started using a larger resonator that resembled a suitcase (pictured below). This large clunky piece not only weighed a good bit but toned down the exhaust immensely. We quickly came out with a resonator delete pipe and they have certainly become a best seller. 

 

The 2015-up Mustang GT & GT350 "suitcase"

 

With the 2020 Shelby GT500, Ford has foregone the suitcase (rejoice!) but still retains resonators in the exhaust (just a more bullet style resonator rather than a weekend getaway case). Also located on this resonator section is a large cast X-section. They got rid of the weighty suitcase and replaced it with a heavy pipe. Potato, potah-to. 

Before cars were even hitting the streets, we worked with multiple insiders to start development of our Resonator Delete X-pipe  for the new 2020 Shelby GT500. 

 

 

Since our car is delayed (unfortunate, but that carbon fiber track pack will be worth it), we headed down to Palm Beach Dyno & RareFab to have the X-pipe installed on PBD’s head honcho Ken Bjonnes’ beautiful blue Shelby. 
 

 

Check out the video for the installation, dyno results AND the before & after sound clips.

 

Check out Ken's full review & sound clips with awesome audio to get a real feel of this awesome exhaust setup!

 

CLICK HERE for our Lethal Performance stainless steel resonator delete X-pipe!

 

After taking the car for a spin and getting some stock sound clips, we put the car on the dyno to get some baseline numbers. In previous years, a resonator delete generally didn’t give any horsepower but this was a different type of animal we were working with (a Predator, ha…ha…). 

 

Ken Bjonnes', head tuner at Palm Beach Dyno, 2020 Shelby GT500 on the dyno. 

 

Ken put the car on the rollers and put down 676rwhp and 556 rwtq, bone stock. 

After the dyno, it was time to head next door to RareFab and let Will begin the installation. 

The first (and most crucial) step is to measure where you will be cutting your factory catback. You will want to make sure that the front OEM clamps are locked into place. You will need to measure 30.5 INCHES  from the CENTER of the front clamps back towards the rear of the car and mark the 2 catback pipes. These will be your cut lines.

 

Make sure, before measuring, that the front clamps are locked into place.

 

You will want to measure 30.5 inches from the center of the front clamp to the rear.

 

Make sure to mark on the pipe where you are supposed to cut. 

 

Next, using a cutting wheel (or similar) cut the factory exhaust ties holding the heat shield in place above the resonator pipe. You have the option to reinstall this later, so take care not to damage it.

 

Cut off the 4 factory exhaust ties.

 

Once the heat shield is removed, you will want to support the exhaust. Use a tranny jack or jack stand to support the X-section and zip ties (or similar) to hold the catback pipes in place. Will used zip ties before the mufflers. 

 

Support the catback so that when the stock X-pipe is cut, it does not sag/drop and damage the rear bumper or tips.

 

Once the exhaust is supported, you can make your cuts using a sawzall. 


CAUTION: Please use proper safety gear. Also, be careful not to damage either the carbon fiber driveshaft or the fuel tank on each side. 

 

Use caution when cutting the exhaust as the fuel tank & carbon fiber driveshaft are in the same area.

 

After your cuts are made, loosen the front exhaust clamps using a 15mm socket and remove the factory resonator X-pipe. 

 

Use a 15mm socket to loosen the factory clamps.

 

It is recommended to clean up & deburr the catback pipes where you cut them as the jagged edges can lead to leaks, etc. 

Remove the front clamps by unclipping them from the fastener. 

 

Unclip the clamp fasteners to remove them.

 

Place the supplied rear clamps over the two factory catback pipes and then slide the rear section of the Lethal Performance Resonator Delete X-pipe over the stock catback pipes.

 

Slide the supplied rear clamps over the catback pipes before sliding the X-pipe onto them.

 

Install the front clamps onto the Lethal Performance Resonator Delete X-pipe and slide the factory cat pipes into each side. Adjust as needed for proper alignment. Then, lock the clamps back to the fastener and tighten all four exhaust clamps. 

 

After placing all 4 clamps, support the X-pipe before tightening for proper alignment.

 

If you wish to reinstall the heat shield (recommended) you will need to modify it to fit over our Lethal Performance Resonator Delete X-pipe. 

You will need to cut the front section off of the shield and also drill a hole into the first dimple so that the exhaust ties can be clip through it to attach it to the X-pipe. 

 

You will need to modify the factory heat shield to fit over the Lethal Performance X-pipe.

 

You will want to cut the front portion of the heat shield off to clear the Lethal Performance X-pipe.

 

You will need to drill a new hole in the middle of the heat shield to allow the supplied stainless steel exhaust ties to pass through and clamp down.

 

Once you’ve made your cut and hole, place the heat shield back over the X-pipe and secure it with the supplied exhaust ties. You will notice that the section of the heat shield you cut off still has another factory heat shield behind it, giving protection where needed between the exhaust and the driveshaft. 

 

Even with the front part of the heat shield removed, the driveshaft is still protected by an upper heat shield plate.

 

Congrats, you’ve now installed our Lethal Performance Resonator Delete X-pipe on your 2020 Shelby GT500.  Want more upgrades? Check out our collection of 2020 GT500 parts today.

 

Here is the Lethal Performance Resonator Delete X-pipe installed on a 2020 Shelby GT500.

 

After we finished our install, we headed back over to Palm Beach Dyno to get some final numbers. We were curious to see if the X-pipe picked up any power. 

The dyno was done on the same day in the same conditions. The Lethal Performance Resonator Delete X-pipe gained 7rwhp overall with a peak gain of 16rwhp at 6600rpms. Oh and it sounds meaner, too. 

 

On Ken B.'s 2020 GT500, the Lethal Performance Resonator Delete X-pipe picked up a peak 16rwhp at 6645rpm.

 

Ready to get one for your own GT500?? CLICK HERE!

 

If you have any questions on this or any other part we carry, give us a shout!

#teamlethal