Performance Upgrade Package

GymC · March 30, 2019

2 hours ago, Jmonty said:

Any drone? How much louder did it get?

There is a little, I'm not sure if it's any different than the GM Cat back system. It doesnt bother me at all. I kept the flapper valves just in case and I have no intention of welding them back on.

SierraAT4 · March 30, 2019

I just put on the GM cat back system this morning...really solid. I can't compare it to what people are getting by just replacing the muffler and cutting out the flappers, but I will say that I'm really impressed. Lots of balls when you're into the throttle, very subdued at highway cruising speeds (I suspect this is largely due to the 10 speed keeping a low RPM when you're not passing somebody).

Great balance. Went on super easy.

PhilB · March 31, 2019

13 hours ago, SierraAT4 said:

I just put on the GM cat back system this morning...really solid. I can't compare it to what people are getting by just replacing the muffler and cutting out the flappers, but I will say that I'm really impressed. Lots of balls when you're into the throttle, very subdued at highway cruising speeds (I suspect this is largely due to the 10 speed keeping a low RPM when you're not passing somebody).

Great balance. Went on super easy.

I have been contemplating the GM cat back and installing it myself. When you removed the OEM exhaust, did you have to cut it to get it out?

SierraAT4 · March 31, 2019

Ok, so we got it out without cutting it, but this was on a lift with two people manipulating the exhaust back and forth. It takes a little tetris/gymnastics to get it out of there in one piece, but it is 100% doable. On the ground or on jackstands? I'm not sure I would have bothered trying to get it out in one piece.

Of course, once we got it out and realized how long it was, and I had no easy way to transport it (and no real potential to sell it, it's likely going to end up at the recycler), we ended it up cutting it just past the second flapper so I could stick it all in the bed of my truck.

My advice would be to just cut it out with a sawzall, one cut will make pulling the old one out 10x easier. And then the new one goes in exactly as you would expect it to. There aren't any instructions in the box (other than to consult the official accessory service manual, AKA have your dealer do this), but you really don't need any, it pretty much fits together and hangs perfectly. Keep the existing clamp from where the flex pipe connects up toward the front, you'll reuse that one, everything else is in the box.

Edited March 31, 2019 by SierraAT4

Jacksfan98 · April 3, 2019

How loud is the performance exhaust in the backseat when you are pulling a trailer and the engine is running between 2600-2800 rpm?

BillyDee · April 9, 2019

On 3/18/2019 at 8:36 PM, SierraAT4 said:

This video convinced me to buy one:

Thanks for that. I hadn't seen it before, but it consistent with the difference I saw when adding the exhaust and cold air intake. My understanding is that it is the Borla exhaust branded as GM. $2,000 for both installed, but a nice upgrade.

L86 All Terrain · April 12, 2019

On ‎2019‎-‎03‎-‎21 at 9:44 AM, brothernov said:

Would it make any sense to only add the cold air intake, or only the exhaust? As I type it it feels like a dumb question, if I increase the air in I'll probably need to increase the trucks ability to expel it, but I know practically nothing about exhaust systems.

Yes. This is what I do with my personal trucks. I put a cold air intake in them and leave the exhaust stock. That way, I only hear the engine noise under load, under normal driving conditions it is silent. This allows me to go on long drives with ZERO exhaust drone. I had a Magnaflow muffler in my 2010 and it was droney, I would end up with a migraine after a 4hr drive. This has been my method ever since to get some noise, hear your motor, but not be droned out so much you hate driving your own truck.

bshort · April 20, 2019

Who's got the best price on the GM exhaust?

mrcribbs · April 20, 2019

1 hour ago, bshort said:

Who's got the best price on the GM exhaust?

When I bought mine it was shop Chevy parts dot com

OnTheReel · April 20, 2019

3 hours ago, mrcribbs said:

When I bought mine it was shop Chevy parts dot com

Yup. They have a 5% off promo code at the bottom on the site too. Shipping is the only wild card. It was very reasonable for me but if you’re far away it may wind up costing more than ordering at the dealer and having it sent to them.

brothernov · April 25, 2019

Just noticed the little silver "performance" badge mixed in with the paperwork that comes with the performance package. Anyone stick this on their truck? I'm curious where you put it. I won't be using mine, it has a Chevy Logo on it, I've got an AT4

Docman · April 27, 2019

Test drove an AT4 yesterday with a 6.2 and performance package. Just barely louder than my current 2010 with a 6.2, 3.73 gears, stock exhaust, and K&N CAI. Couldn’t notice sound at all unless I punched it a little. It did seem a little more responsive to the throttle than mine. I went ahead and put my order in!