5.3 4l60 vs 6l80

patooyee · May 6, 2015

My brother used to have a 2wd 2003 Tahoe, all stock, 5.3L, 3.55 rear end. That thing flat-out could get it, was very fun to drive. Of course it had the 4l60 trans.

Then I test drove a 4wd 2010 6.0 Sierra 2500 with the 6L80. I think it had a 3.73 rear and it was so weak that it was almost unbearable to drive. It couldn't get out of its own way.

I recently bought my wife a 2013 5.3 Tahoe with the 6l80, 3.55 and its weak as ****, too. I mean, its fine for her, but you stomp the gas and its nothing like my brother's old Tahoe. Total weak sauce.

Of course I have an LS2 in my buggy and it fricken smokes the tires when I want it to. But I don't think I can compare my buggy to the above.

So is the 6L80 just a power hog? The way that all the west coast racers talk about it its the be-all and end-all of transmissions.

Mortalis5509 · May 6, 2015

Re:

It's has a really deep first gear. Maybe it's something chevy is doing to the Gen 4 set up that's causing.

bbone · May 6, 2015

might have something to do with having better mpg across the board for all cars/trucks

TacomaJD · May 6, 2015

Hard to believe a 6.0 HD with 6l80 would be described as weak as ****. I had an 02 4wd loaded Yukon with 5.3L and whatever tranny/gears came in that model ( never checked while I had it ), running 20" wheels and 32" tires - and my current rig ( 06 2500HD with 6.0, 4L80, 4:10 gears and 33" tires) has significantly more power than my old Yukon did, and it never seemed as if it was a slouch....even with the oversized wheels and tires. I have a Diablosport tuner on my rig and have messed with the shift points and shift pressure and it feels like a different truck and is more "driveable".....you may have to do that, although with the 6l80 being a 6 speed vs mine being a 4 speed, it may not make that much of a difference? I know the shift points were set terrible from the factory on my current truck. The 6.0 is no 8.1 or diesel, but it is by far a slouch, especially if it's in a half ton.

TacomaJD · May 6, 2015

My buddy's wife had an 08 or 09 Tahoe with the 4.8 in it that we all drove on a couple long trips, and it felt to me like it had as much power as my old 02 Yukon with the 5.3!

TBItoy · May 6, 2015

I wonder if part of it is "perceived" power from the 4 speed vs the 6 speed?

Like if you are cruising in OD with a 4L60/80 and you mat it, it will drop to 2nd and hit redline.

Maybe with the 6L it only drops a bit and smoothly accelerates instead of the sudden spike of big gear jump?

I'm sure a lot of it could be tuned more aggressively with software....

A big thing I've read a lot about is removing torque management via tuning.

Seems to be a big problem with the V8 Colorado especially, GM basically neutered the truck by severely limiting how much actual throttle input is "allowed" vs how much your foot is telling it!

The 6L80/90 with a tap shift controller seems like it would be hot ****, especially since the low first gear pretty much negates the need for doublers or deep Tcase gearing.

patooyee · May 6, 2015

One other comparison ... I have a 2012 2wd Dodge Hemi as a company truck. I don't know what trans it has, 3.55 rear, and it will fricken smoke the over loving **** out of my wife's Tahoe or the 6.0 I drove. I mean, it would not even be funny in a drag race. Within a second the Chevy would be a distant speck in the rear view mirror. By seat of the pants feel it has at least double the power of either of the newer Chevies and that is not an exaggeration in the least. And I am an LS guy. I know what the LS motors are capable of. GM obviously has them hindered in some way.

86tank · May 6, 2015

My father in law has either an 11 or 12 GMC half ton with the 5.3 and the 6 speed auto and it doesnt seem to anywhere close the power of my old 00 z71 with the same engine and 4l60e. One thing Ive noticed is his truck seems to shift ALL the time. Its like its never able to find the right gear. Im almost positive his has 3.73s and know thats what mine has.

09zkrankin · May 6, 2015

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My 2011 2500 has the 6.0/ 6l90 combo and I love it, it has plenty of power, but if you try to get it to spin the tires with the traction control on it will flat fall on its face, the dam thing almost dies. With it off, it's a whole nother animal

patooyee · May 6, 2015

Just a minor related side comparison, I used my dad's brand new 2015 Duramax w/Alison trans to pick up a 10,000 lbs fork lift on a 3500 lbs trailer a few weeks ago. I then used my 2005 Cummins w/NV5600 manual trans to tow it back. Let's just say that I won't be trading my Cummins in any time soon. The Dmax supposedly has almost 200 ft/lbs more than my truck but I didn't notice if it did. That Alison is like driving a swimming pool.

patooyee · May 6, 2015

Re:

09zkrankin said:
My 2011 2500 has the 6.0/ 6l90 combo and I love it, it has plenty of power, but if you try to get it to spin the tires with the traction control on it will flat fall on its face, the dam thing almost dies. With it off, it's a whole nother animal

Hm, I'll try turning it off next time I drive the wife's car.

kboring · May 6, 2015

I agree with you about the 6 speeds feeling short on power. I think it's a trans tuning/ torque management issue. One of my service trucks is an 08 2500hd with a 6.0 and 6l90. It feels like it never know what gear it wants to be in. Drops out of 6th on flat ground with the cruise set.

I had 07 Sierra Denali with 6.2 and 6 speed that was the same way - got Blackbear to tune it and pull out the tq management and was night and day.

onepieceatatime · May 6, 2015

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I think most of the problem is torque management. I've turned it off on my old 5.3 truck and my new 8.1 and it's makes for an entirely different vehicle. The motors themselves make crazy power but the computers try and save every thing else so it de-tunes them a lot.

MoparMan · May 6, 2015

patooyee said:
One other comparison ... I have a 2012 2wd Dodge Hemi as a company truck. I don't know what trans it has, 3.55 rear, and it will fricken smoke the over loving **** out of my wife's Tahoe or the 6.0 I drove. I mean, it would not even be funny in a drag race. Within a second the Chevy would be a distant speck in the rear view mirror. By seat of the pants feel it has at least double the power of either of the newer Chevies and that is not an exaggeration in the least. And I am an LS guy. I know what the LS motors are capable of. GM obviously has them hindered in some way.

Trans is 65RFE 6-speed. I've got several friends with LS powered trucks and every time they drive a Ram with a HEMI in it they are surprised by the power and say they'd like to have one instead of their GM. Only LS powered truck/suv that has ever impressed me a little bit is an Escalade w/6.2

Puppy · May 7, 2015

It has to be the programming/ drive by wire/fuel economy crap that causes this. I play with the pedal on my 2011 1500 all the time and it is clear that the truck does not respond to my pedal inputs, rather takes them as a suggestion. I know there is way more potential under the hood than I can get out of it most days.

patooyee · May 9, 2015

kboring said:
It feels like it never know what gear it wants to be in.

I can identify with that on both the Tahoe and my Dodge 1500. I scare my wife sometimes taking off from stoplights. Both trucks will sometimes just easily take off like they should with moderate pedal pressure. But then other times both trucks will all-out drop gear to first and let me rev the **** out of the motor, slamming us all into the backs of our seats. Wife hollars at me, I appologize, say it was the trans being indecisive. And then other times when I need to jump da fuk up and get into a lane or out of someone's way I'll slam the pedal to the floor and they will just sit there in 6th gear slowly accelerating, 0 to 60 in 5 minutes flat! It pisses me off so bad. I never know WTF to expect out of either truck.