Need Advice for 08 silverado exhaust system

**JKEY817** · 06-26-2008, 11:49 AM

I just got a 2008 silverado texas edition with the 5.3L and AFM. I am wanting to get after-market exhaust, half of my friends say get it dumped, my auto savy friends say it wont sound good when it switches over to 4 cylinders. I dont want a loud annoying tone at all, just something that sounds smooth and will help out with the engine.

**Pete95Sierra** · 06-26-2008, 07:18 PM

i have heard that the exhaust note doesnt change much when it goes in the 4 cyl mode but dont quote me on it. anyone know for sure?? you could start by looking for aftermarket exhaust systems from magnaflow, borla and flowmaster. or you could have a shop bend one up for you with whatever mufflers you choose from the same manufacturers i listed. it would be cool dumped but that attracts way to much attention from cops so that is why i havnt done that to mine

**ctruhn** · 06-27-2008, 12:21 AM

IMO it doesn't matter that it it will lose some of the tone when AFM kicks in. It won't go down to 4cyl mode unless you are decelerating or on flat highway on cruise, in both cases you won't really hear the change all that much. I have heard 5.3's at idle with exhaust which sounds very nice. The manufacturers are aware of the change so I have to imagine they take that into account.

I want exhaust on mine, but I can't convince myself to part with the cash for it... Maybe one day I will.

**branhap** · 06-27-2008, 10:40 AM

From what I've read elsewhere Corsa and Borla both work well with AFM. Corsa used to be the manufacturer of the GMPP exhaust system. Borla is now. So they both had to work with GM to make sure it didn't sound like crap when afm engaged.

Hope this helps. So basically, go GMPP, Corsa, or Borla.

Read about some issues with Magnaflow on another forum.

Paul

**Eclipse** · 06-27-2008, 04:23 PM

Im in the same boat, 08 silverado texas edition with 5.3, didn't even think about the tone when it drops to 4 cyl, but like most say i dont think it will sound to different, I prob wont dump mine but will run dual out the side or back, what do most perfer for mufflers around here on the 5.3?(dont worry im seraching as well)

**wailalghanim** · 07-02-2008, 02:40 AM

I have the borla catbacks on my 5.3 Sierra, and I can tell you something, when it drops to 4cyl mode,,,,
Man it sounds like ***** , it sounds like those two stroke bikes which you can hear the detonation between bores, I hated my life for one week, but I disabled the AFM from the predator programmer and now it sounds grate, specially that I drive in-town so the AFM actually doesn't engage much time and wouldn't' save that much of fuel.

My advise is to buy a programmer to disengage the AFM if you are going to buy an exhaust.

( note: I am very sensitive to noises in cars so someone else my say the sound of cat's in 4Cyl is bearable )

**Eclipse** · 07-15-2008, 12:26 PM

Just put on true dual custom exhaust, used 50 series flow masters, had them dumped right before the axle, I also had an x pipe put in(4 other reasons), This is on an 08 5.3 AFM, now when it switces over to 4cyl. you can tell, its gets lil louder and a lil more drone noise in the cab, but still not really annoying with this set up and I seem to only switch to 4 when i go down hills/bridges/etc or de-accelerate from like 40+ . other then that would recomend a set up like this good sound but not too loud in cab incase of travel, i'll try and gets some vids up today.

**JKEY817** · 07-15-2008, 11:43 PM

I ended up getting the 40 series Flowmaster muffler, 2 1/4" pipes and 3" tips, its exactly what I want, not loud but has that growl that a truck should have. Cant tell the difference when it switches to 4 cylinders.

**DrewsZ71** · 07-27-2008, 09:58 AM

I have an 07 NBS and i just had a magnaflow muffler and had a shop do all the piping for me. It sounds awesome and very smooth. When it kicks down to 4cyl mode, you can barely hear it. Of course if you're driving by something that reflects the sound you might hear some of it droning. Go with the magnaflow, I love mine and get complements all the time on it

**kevinmach1** · 08-01-2008, 10:04 AM

I just went through this with my 08 Silverado CC 5.3 AFM. I took it to a shop, had them install a magnaflow and split it into duals out the back. I have done this on numerous otherr trucks.

It sounded OK, but the drone at 55-65 mph was unbearable. I had them add a bullet muffler in front of the magnaflow, it helped, but still droned. I had them try a dynamas super turbo instead of the magnaflow...NO better. Then as a last resort, I had them add a flowaster in series with the dynamax...NO better.

At this point I am getting rather upset with myself for ever messing with it, so I had them put back on the stock muffler, and had them split right after the muffler for the duals out the back...

Finally I got the looks I wanted with the duals, It actually sounds aggresive, and best of all...NO DRONE, and I think it even runs better!!!.

I couldn't be happier if I was twins...

My advise, just get the duals added behind the stock muffler...