2021 GMC Denali exhaust.

Mike31 · August 19, 2020

we got ours about 2 weeks ago with the 6.2 and got the exauhst replaced today with a delta flow 50 series flowmaster, both flaps cut out and it is not near as sluggish now major improvement. I know most people won't want an exauhst on an suv but the lack of power with it being a 6.2 somewhat bugged me.

Denali2021 · August 19, 2020

we got ours about 2 weeks ago with the 6.2 and got the exauhst replaced today with a delta flow 50 series flowmaster, both flaps cut out and it is not near as sluggish now major improvement. I know most people won't want an exauhst on an suv but the lack of power with it being a 6.2 somewhat bugged me.

You know I thought I was a bit crazy thinking my Denali was a bit sluggish as well. Seems slower than my old 2002 Tahoe with the 5.3 and also slower than a new model Grand Cherokee with the 3.6 v6. I know it's a lot of weight but expected a bit better out of the 6.2 with the 10 spd. It does move out its own way well at highway speeds thanks to momentum and torque but city driving below 60 mph I'm wanting a bit more.

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Mike31 · August 19, 2020

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Edited August 20, 2020 by Mike31

newdude · August 19, 2020

Placebo. Your foot is in it more now because sound...

amxguy1970 · August 19, 2020

2 hours ago, newdude said:

Placebo. Your foot is in it more now because sound...

This, it didn't add any noticeable or measurable power.

2 hours ago, Mike31 said:

That was my issue with it as well. I have a 2020 at4 woth the 6.2 and tbh it's funner then the 2013 camaro ss i had so i just expected more but not as much as the at4 out of the yukon. Honestly I was afraid it wouldn't change much replacing the exauhst but again it definitely helped and I'm happy with it. They're not race cars i know but pay for the big motor i want to feel a little power.

What? So the Camaro is faster, handles better, stops better, is better balanced and sounds better yet the nearly six thousand pound truck with the same horesepower is more fun? Care to explain this?

2 hours ago, Mike31 said:

we got ours about 2 weeks ago with the 6.2 and got the exauhst replaced today with a delta flow 50 series flowmaster, both flaps cut out and it is not near as sluggish now major improvement. I know most people won't want an exauhst on an suv but the lack of power with it being a 6.2 somewhat bugged me.

Major improvement? How much did it show on the dyno? Flowmasters are never know for giving good HP because they are a chambered muffler that adds restrictions and increases the chance of drone, so no real power was gained there as well as removing the flap wasn't a choke point. So as newdude said it is just a placebo effect.

Tyler

Mike31 · August 19, 2020

18 hours ago, amxguy1970 said:

This, it didn't add any noticeable or measurable power.

What? So the Camaro is faster, handles better, stops better, is better balanced and sounds better yet the nearly six thousand pound truck with the same horesepower is more fun? Care to explain this?

Major improvement? How much did it show on the dyno? Flowmasters are never know for giving good HP because they are a chambered muffler that adds restrictions and increases the chance of drone, so no real power was gained there as well as removing the flap wasn't a choke point. So as newdude said it is just a placebo effect.

Edited August 20, 2020 by Mike31

Denali2021 · August 19, 2020

1 hour ago, Mike31 said:

On the camaro yes. AT4 can go off road, puts you back in the seat when you hit it at take off or highway speed, handles better then any other truck I've owned, won't be stuck in the garage when it snows and makes enough power i have pulled away from my 2010 gt at a start of 65mph so makes me happy enough besides the fact its a truck and I can haul my river toys. Never said it was better performance wise but in many other ways it is.

For the other comment. Never said it gained any power and I'm not going to put a yukon on a dyno unless I'm adding a supercharger or something of that nature to it but where as before it almost bogged down when I hit it at low speed to merge or what not it no longer does that. Do you have one yet you've messed with to tell me otherwise?

I also own a tuned/slightly modified Challenger RT with a 5.7 Hemi pushing a little over 400 at the crank, I can attest that the butt meter between that one and my 2021 Denali are not as close as I would have thought. Apples and oranges I know... And again, can only really compare to the 5.3 in my old 2002 Tahoe, but based on my experience with that 15 yr old 5.3 Vortec, I really did not even want nor consider a real need for the 6.2 in the Yukon as I always thought that Tahoe had sufficient git up in city driving. Was driving both it and my Challenger interchangeably for some time and the butt meter felt much closer. Figured the 6.2 would be overkill but eventually fell in love with the perks/looks of the Denali and went with it, so glad that I did. Haven't driven a new 2021 with the 5.3 but in my opinion I bet there will be some folks complaining of it feeling underpowered since the 6.2 seems just about adequate for the size/weight of this new refresh. Maybe its a programming/transmission thing... I don't know. Test drove a 2020 Expedition with the 3.5 ecoboost before purchasing the Yukon and it felt a bit quicker than my 6.2.... and just think you get that in a 50k base model. Of course it's all anecdotal and we may end up being the minority once more folks get these in their driveways. But I can assure you all that Mike31 is not bs'ing or on a placebo high when he mentions some sluggishness with this new platform. I'm not drag racing this land yacht so at the end of the day it's not a huge deal, as long as the 6.2 does its job when I begin towing. Also not dogging the new 2021 platform nor do I regret my decision, it's the best full size suv out there right now imo... but it is an honest observation from someone who isn't just some paid car reviewer but someone who spent their hard earned money on this suv.

Mike31 · August 19, 2020

Anyways whoever may actually know about the low end sluggish feel we are talking about "imo" changing the muffler did help a lot. Went with the delta 50 because I did get this yukon for my fiance and I didn't want it very loud even know it turned out louder then expected but with low interior noise. I'm sure there's better options for muffler choice out there but it's what they had and I'm to inpatient to wait till they start making kits for them. I'll add a picture or two of the muffler that came off the yukon and the one that came off my 2020 at4. Both 6.2 with the 10 speeds. I'm not an exauhst expert but there is a difference in size plus the 2 flaps on the yukon where there was only 1 on the at4 sierra. The bigger one on left is the yukon maybe it had something to do with the low end sluggishness maybe it didn't.