'19 5.3l exhaust pipe size, muffler suggestions?

Mangano · April 14, 2020

I bought a Borla 40359, deleted the flapper and covered the resonators and it sounds awesome. Deep rumble which I prefer.

The muffler shop that replaced the muffler said it would be same as factory. Ha. The Borla muffler is much "louder" and not obnoxious.

papasink · May 4, 2020

On 3/31/2020 at 2:29 PM, crazyjoefound said:

2018 & 2019 Silverado 1500 LTZ Z71's seem to have the same diameter stock pipe of 2.75" plus the 2019 has new tech resonators. I have both a 2018 and 2019 Silverado. On the 19 have done the muffler delete, welded in a 3 inch diameter pipe, and covered all 6 screens (dual exit). The 18 has the same layout minus the new resonators and I deleted the muffler and resonator by welding in replacement 3 inch pipe. The 19 is much louder on cold start and through the rev range, but for less than $50 and a diy weld job the sound is great. Also removed flapper valves on both and with AFM there is a noticeable hum at speed, but the DFM hum is mitigated due to the exit of the exhaust being out the rear.

Quick question on the dual exhaust for the 19. I have the RST and want to just replace the muffler (I covered the resonators already and have the flap open) but looking at Super 10 and they have 2 styles with dual outlet. Inlet is centered (#8425152) on one but offset (#8425810)on the other. Which kind do you have, centered? Thanks. Love the "stock" sound but want a little more.

crazyjoefound · May 4, 2020

@papasink I deleted the muffler and have welded in a straight 3 inch pipe. The pipe exits into a Y to the factory dual exit locations, and with the first muffler right after the cats then the flex-pipe having it "straight piped" into the said dual exit has made it louder that my '18 with only one exit. I will take a video showing the setup after work.

Mangano · May 4, 2020

What I did is to purchase a Borla Model 40359 muffler, ditched the flapper and left the resonators. If you cover all six resonators it gets pretty loud and has some drone under load. I hit pay dirt using 1 and 1/2 resonators covered on each side.

To cover them I used: Thermo Tec 13575 12" x 24" Adhesive Backed Heat Barrier Thermal Pad Mat Tape NEW purchased on fleabay. It can be cut to size and wrapped around them. No slippage.

Edited May 4, 2020 by Mangano