My stock muffler is beginning to rust out with some pinholes here and there. I like the quietness of the stock muffler. And the resonator seems to also help. Eventually I will have to replace the muffler. Is there any muffler and resonator combo that will keep things about the same decibels but increase performance and/or gas mileage ?
Replacement muffler. Possible performance increases? Recommendations please.
- Thread starter c good
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Mike534x
Member
- Apr 9, 2012
- 931
Unfortunately, at least with these trucks a muffler/resonator change won't do much to help performance/gas mileage. At you just looking to cut out the old muffler, and have a new one welded in or do a full exhaust replacement? I know Walker offers a complete kit, or you can purchase just the muffler + resonator and have them cut/welded in. The Walker muffler is pretty much an OE replacement, so there won't be a noise increase.
If you're looking for gas mileage increases, a good highway tread tire with the least amount of rolling resistance will net you a tiny bit. Same goes for a tune (from Limeswap or PCM of NC) since you won't be laying into the throttle much to get her going. Otherwise, make sure the O2 sensors are operating within spec since that'll be another hit to MPG, and maybe a tune up/run some Redline fuel cleaner to help clear carbon build up.
Having been near a Trailblazer with both the resonator on and removed, especially on the I6 there wasn't much if any of a noise increase even under acceleration. The resonator is really just unneeded weight in the rear. Now if you had the V8, there would be a noticeable ton/noise output, same goes for the I6 if you slapped a Cherry, Magnaflow, Flowmaster, Borla or whatever then yeah the resonator would help tame the sound. I would just get the old one cut and removed, and let the resonator eventually rust off or get it removed and you'll be good!
If you're looking for gas mileage increases, a good highway tread tire with the least amount of rolling resistance will net you a tiny bit. Same goes for a tune (from Limeswap or PCM of NC) since you won't be laying into the throttle much to get her going. Otherwise, make sure the O2 sensors are operating within spec since that'll be another hit to MPG, and maybe a tune up/run some Redline fuel cleaner to help clear carbon build up.
Having been near a Trailblazer with both the resonator on and removed, especially on the I6 there wasn't much if any of a noise increase even under acceleration. The resonator is really just unneeded weight in the rear. Now if you had the V8, there would be a noticeable ton/noise output, same goes for the I6 if you slapped a Cherry, Magnaflow, Flowmaster, Borla or whatever then yeah the resonator would help tame the sound. I would just get the old one cut and removed, and let the resonator eventually rust off or get it removed and you'll be good!
Mooseman
Moderator
Just be aware that a lot of aftermarket replacement mufflers, especially Walker, have internal necked-down pipes. That's because this platform uses a weird 2.75" pipe size and they just adapted to that with 2.5" mufflers with a 2 MPG drop.
gmtnation.com
It might be worth it to search for a 3" muffler and use adapters to 2.75" (if available) or get a muffler shop to fabricate something. I remember someone here using an older big block full size truck muffler with good results. Can't remember if the V8 version of our trucks use 3" mufflers. 2002-2005 use the same mufflers for both according to RA. They don't list anything for V8 for 2006-2009, neither does Walker.
Just installed Walker Quiet Flow SS exhaust...
To avoid confusion......it's not the TBSS exhaust I use the direct-fit muffler and resonator, installation was a breeze. Idle is quiet, cruise is quiet, only thing I notice sound-wise is hard acceleration there is a slight rasp but not bad, just slightly louder than stock. The bad.......I...
gmtnation.com
It might be worth it to search for a 3" muffler and use adapters to 2.75" (if available) or get a muffler shop to fabricate something. I remember someone here using an older big block full size truck muffler with good results. Can't remember if the V8 version of our trucks use 3" mufflers. 2002-2005 use the same mufflers for both according to RA. They don't list anything for V8 for 2006-2009, neither does Walker.
