18" Magnaflow w/ resonator and flapper

kkmitchell5 · December 21, 2016

I have read every muffler swap, delete, topic, post, on this forum and have not found anything of anyone using a smaller case muffler (magna flow) and leaving the resonator and flapper in. Has any one done it or tried it before they cut out one or the other? Im currently looking at running Magnaflow 12259 18" with resonator and flapper or Magnaflow 12589 22" and resonator delete and keeping flapper in.

Would either of those setups achieve this:

NO drone/chopper

I dont want it too loud

quiet on cruise

nice low key rumble on start, idle, and getting after it

turnerms98 · December 21, 2016

I know it's not what you ask, but I have Magnaflow 12259 flapper and resonator delete and I love it. My wife even says it's not loud enough!! I will try to post video later today. It will be with phone though so may not be that great of quality!

kkmitchell5 · December 22, 2016

no one?

CoachH · January 20, 2017

I have a similar setup- magnaflow, kept the flapper, side exit duals, deleted the resonator. Sounds good at start, sounds great when punched - not obnoxiously loud. Hardly noticeable at highway speed. A great system until the truck drops to V4. Sounds like crap then. I wouldn't call it a drone, but a definite difference can be heard.

Overall I'm ok with the sound. I am going to wire the flapper open and see what that does.

I have the 6.2l for reference.

KARNUT · January 20, 2017

no one?

I did muffler delete left everything else had the V4 sound put on a magnaflow still had it. Did every thing else you wanted but still had the V4 sound. I tuned out the V4 perfect after that. I tried everything if you don't want to do the tune or buy the expensive GM backed exhaust your going to have that sound. And that's a fact jack.

kkmitchell5 · January 20, 2017

I have a similar setup- magnaflow, kept the flapper, side exit duals, deleted the resonator. Sounds good at start, sounds great when punched - not obnoxiously loud. Hardly noticeable at highway speed. A great system until the truck drops to V4. Sounds like crap then. I wouldn't call it a drone, but a definite difference can be heard.

Overall I'm ok with the sound. I am going to wire the flapper open and see what that does.

I have the 6.2l for reference.

I did muffler delete left everything else had the V4 sound put on a magnaflow still had it. Did every thing else you wanted but still had the V4 sound. I tuned out the V4 perfect after that. I tried everything if you don't want to do the tune or buy the expensive GM backed exhaust your going to have that sound. And that's a fact jack.

Thanks for the input guys. Right now i just did muffler delete and move resonator to muffler location and have the flapper clamped open. When it drops to V4 it isn't to bad. I just tried this as seeing so many people love the muffler delete. So i have my 18" Magnaflow at the house so in the coming weeks i think ill put that in the original muffler location and might just run 3" all the way to the tip and leave resonator out. If i dont like that then ill just throw the resonator in the factory spot and basically just run it factory besides the muffler.