Sign up for FREE! Become a GM-Trucks.com Member Today!
In 20 seconds you can become part of the worlds largest and oldest community discussing General Motors, Chevrolet and GMC branded pickups, crossovers, and SUVs. From buying research to owner support, join 1.5 MILLION GM Truck Enthusiasts every month who use GM-Trucks.com as a daily part of their ownership experience.
So I’m currently running the 12909 Magnaflow 3.5” 22 inch muffler and have been eyeballing the Magnaflow 15278 catback system for the RCSB Sierra. The problem is that the catback comes with an 18 inch muffler rather than a 22 so I expect that it’d be louder, but by how much?
I currently really like the sound of the 22” muffler while running LTs and a catless y-pipe but I’m afraid that if I decide to fork out money for the catback it would just be way too loud. Anybody ever used an 18” inch Magnaflow with long tubes?
Replaced the stock muffler with the Magnaflow 11229 which has 3” in and out. Initially, the exhaust shop removed both flappers. It sounded very deep and rumbly but a bit louder than I preferred. The drone especially on the highway was unbearable.After emailing Magnaflow support, they recommended I have the shop put the flappers back on so I had both flappers welded back in. The flappers completely eliminated the drone but did quiet down the muffler quite a bit. Now, it’s about 70% as loud as the GM performance exhaust which is the perfect level of loudness I was aiming for. I didn’t want anything obnoxious. Sounds really good when you put your foot in it. Cold start (attached) is equally as lively.
If you find the GM performance exhaust a bit too loud for you, then this mod will be the perfect volume level. Just save yourself the headache and money by having the shop install the flappers from the get go. Cost me $220 for muffler and install. $80 to weld the flappers back in. All in all, very pleased with it.
Sold my 2015 Silverado a few weeks ago and bought a new GMC Sierra SLT with the z71 package and the 6.2L v8!
Had the camper shell moved over and sold the Silverado to my dad.
It's been a great change so far. Nicer interior so my wife and daughter enjoy it. It's much quieter with the active noise cancellation, and the thing just SCOOTS!
My 5.3 that i had before was modded and would move pretty quick but this 6.2 just puts it TO SHAME.
Installed an AFE Momentum GT Intake on it a few days ago and it's even better.
Just cracked 1000 miles over the weekend and it's already better on gas mileage, ride quality and everything in between than the silverado was.
Very excited for the modifications to come.
Looking to add some fox coilovers to all 4 corners in the next week or so, which will level it out and lift the front end.
Will then upgrade to 10 ply tires, probably a good bit taller than stock. (thinking about cooper at3 XLT's currently in probably 275/65R20 or 285/60R20)
Then planning to put airbags on the back for towing.
Still undecided on exhaust setup, but will plan to do that and probably tune it in the future as well.
Anyways, heres a pic of the truck when i picked it up. i'll post some pics of the intake after installation as well.
Recently Browsing 0 members
No registered users viewing this page.
Most OnlineNewest Member
Who's Online 60 Members, 0 Anonymous, 1,638 Guests (See full list)
- Jared Hoefsmit
- Miguel Olea
- Mike Barber
- Grumpy Bear
- Juan Yanez
- Ryker Tapson
- Kole Zimmer
- Old wrench 🛠
- Yuri Srb