Magnaflow 22inch or 24 inch

[Graphite Silverado 2018]

Anyone out there using a magnaflow 22 inch or 24 inch muffler, no flapper no resonator? How does it sound? Deep mellow? Or annoying and drony? Currently running a super 44. Too loud, need to mellow it down a bit. Vancouver is cracking down on loud pipes. Thanks

[Lgetz]

Currently using a Magnaflow 12909 on my 6.2 which is a 5x11x22 inch muffler.  Flapper valve was deleted but kept resonator on because I do tow some.  Deep, mellow sounding exhaust which is slightly louder than stock.  Others have removed the resonator with no issues but YMMV.  

If you have a 5.3 a 12589 is the same muffler but with 3 instead of 3.5 inch inlet/outlet.  A competent exhaust shop will be able to neatly cut out the stock muffler and flapper valve and weld on the new Magnaflow.  As for taking out the resonator an experienced person should be able to fabricate a new exhaust pipe and do a good job.  

Again YMMV.

[Mileguru]

Lgetz said it perfectly. I have the same set-up, 2017 6.2L Sierra with the 12909, no flapper, kept the resonator, disabled V4.

[Graphite Silverado 2018]

Lgetz, couldnt have explained better. Awsome thanks for the opinion. Ill see what i end up with. Thanks for the help, ill let you know how it goes. I can buy a corsa or borla or whatever. But the prices from usd to cad are ridiculous. Rather just cut and weld my own. Its like 2000 for a borla set up installed. Im just looking for a deep nice mellow rumble. Out here on the northwest coast not too many custom exhaust shops out here. 

[Graphite Silverado 2018]

Now if i do a 12589 mf with a single out, no flapper or res, do you guys think ill get drone like the super 44? 

[Graphite Silverado 2018]

Heres an issue im running into with alot of posts on here. Everyone say hell yeah a magnaflow all day everyday, flowmaster is crap and robs power and creates back pressure. People say including magnaflow rep, its only good on mileage at wot. But im only doing everyday city driving from here to there. So will i really lose low end with the magnaflow and do flowmasters really rob power? Do these new 6.2 and 5.3 thrive on back pressure? 

[Lgetz]

16 hours ago, Graphite Silverado 2018 said:

Lgetz, couldnt have explained better. Awsome thanks for the opinion. Ill see what i end up with. Thanks for the help, ill let you know how it goes. I can buy a corsa or borla or whatever. But the prices from usd to cad are ridiculous. Rather just cut and weld my own. Its like 2000 for a borla set up installed. Im just looking for a deep nice mellow rumble. Out here on the northwest coast not too many custom exhaust shops out here. 

I am a cheap Sonuva myself.  For the money with an online coupon $155 installed was a heck of a deal for the Magnaflow 12909 IMO.

 

16 hours ago, Graphite Silverado 2018 said:

Now if i do a 12589 mf with a single out, no flapper or res, do you guys think ill get drone like the super 44? 

I feel you will not get as much drone with the Magnaflow compared to the Super 44 Flowmaster.

 

16 hours ago, Graphite Silverado 2018 said:

Heres an issue im running into with alot of posts on here. Everyone say hell yeah a magnaflow all day everyday, flowmaster is crap and robs power and creates back pressure. People say including magnaflow rep, its only good on mileage at wot. But im only doing everyday city driving from here to there. So will i really lose low end with the magnaflow and do flowmasters really rob power? Do these new 6.2 and 5.3 thrive on back pressure? 

For daily driving either the Magnaflow or Flowmaster should be good without loss of low end power or torque.  A Flowmaster muffler to consider for a quieter sound is the 53071 which measures 5x10x22.  It is a 70 Series which has "mild sound" according to their website as opposed to "deep aggressive sound" used to describe the Super 44 muffler.  

A test I recall seeing good results from was NorCalSS on a previous body style Escalade.  With a Magnaflow 12909 it made 11 horses more on the Dyno compared to stock.

[2018GMC]

On 7/28/2019 at 4:05 PM, Lgetz said:

Currently using a Magnaflow 12909 on my 6.2 which is a 5x11x22 inch muffler.  Flapper valve was deleted but kept resonator on because I do tow some.  Deep, mellow sounding exhaust which is slightly louder than stock.  Others have removed the resonator with no issues but YMMV.  

If you have a 5.3 a 12589 is the same muffler but with 3 instead of 3.5 inch inlet/outlet.  A competent exhaust shop will be able to neatly cut out the stock muffler and flapper valve and weld on the new Magnaflow.  As for taking out the resonator an experienced person should be able to fabricate a new exhaust pipe and do a good job.  

Again YMMV.

I’m with you. Magnaflow 14909 (stainless). Could barely tell difference in cab unless above 3k rpm. I can now hear cold starts in the house. I can hear my exhaust more and a lot of intake noise with the AFE Momentum intake I scored lightly used.

 

 magnaflow on eBay, local exhaust shop cut out flapper and old muffler, welded in new $80 

[2018GMC]

GM rated the 2019 6.2L with GM cold air intake and GM performance exhaust. 

435hp 469tq vs 420hp 460tq Same engine as K2xx except for DFM instead of AFM

+15hp +9tq at the rear wheels form a different muffler and cold air intake.