2021 GMC 5.3L Tuner suggestions

BassDaggett · March 8, 2021

I bought a new 2021 GMC Sierra 1500 Elevation with 5.3L after my 2016 RAM Ecodiesel blew at 179k ... Yeah, I know its a Dodge. No, I will never buy another RAM again.... That being said, I seriously miss the fuel mileage and low end torque. I know I will have to deal with the fuel mileage, but I'm really looking to boost the low end a little bit when towing. In the past I used a Diablo Predator hand held tuner on my 2009 Silverado 5.3L with good results, but I didn't see anything compatible on their website. What do you use, recommend and why?

Rob Mugs · March 8, 2021

You have one option:

Pay a ton for HPTuners to unlock it and then get it on a dyno. https://www.hptuners.com/product/e90-modified-ecm-purchase-ecm-exchange-service/

The BCM can by manipulated with WAM but he's out of stock ATM https://www.whiteautoandmedia.com/product/t1-pickup-wams-spec-bcm-programming/

redwngr · March 8, 2021

Did you consider the 3.0L?

Full torque at 1500.

From Spec sheet:

TORQUE WHERE IT COUNTS

Diesel engines are all about torque, the LM2 delivers it at low rpm, where it counts when taking off under load. The engine’s peak torque of 460 lb.-ft. (624 Nm) is achieved at only 1,500 rpm, with 95 percent of that max twisting force available by 1,250 rpm. This gives drivers an immediate feeling of pulling power as soon as they touch the gas pedal. Noise-attenuating elements like acoustic resonators and fully decoupled cam covers with rubber-isolated fasteners help curb sound levels for exceptional refinement.

The 6.2L also makes 460 ft-lb, but doesn't get there til 4100

Edited March 8, 2021 by redwngr

asalinasz39 · March 9, 2021

Some of the things available now for our gen are the exhaust gm sells that is supposed to add up to 10hp and 6lb of torque for the 5.3L engine.

2019 Sierra 1500 Crew or Extended Cab Performance Exhaust, 5.3L, Dual Rear, Quad Chrome Tips | 19419435 (shopchevyparts.com)

Another fun one that people are using lately is the pulsar LT inline control Module. With several features including adjusting the pedal sensitivity.

Pulsar LT for 19-20 GM Gas Trucks - Superchips

And last of course you could look into and air intake to pair up well with the exhaust above you can go with the GM intake:

2019 Sierra 1500 Air Intake, Performance, Cold Air, 5.3L Engine | 84789802 (shopchevyparts.com)

or with any other competitors. I personally have the Air Aid intake pipe with a drop in Air aid filter only because I found it on a very good deal at 4wheelparts.com plus they claim an additional 8.8hp and 13.1lb torque on the 6.2L so perhaps at least half of that on the 5.3L

AIR-200-782_dyno.pdf (kandn.com)

BassDaggett · March 9, 2021

15 hours ago, redwngr said:

Did you consider the 3.0L?

Full torque at 1500.

From Spec sheet:

TORQUE WHERE IT COUNTS

Diesel engines are all about torque, the LM2 delivers it at low rpm, where it counts when taking off under load. The engine’s peak torque of 460 lb.-ft. (624 Nm) is achieved at only 1,500 rpm, with 95 percent of that max twisting force available by 1,250 rpm. This gives drivers an immediate feeling of pulling power as soon as they touch the gas pedal. Noise-attenuating elements like acoustic resonators and fully decoupled cam covers with rubber-isolated fasteners help curb sound levels for exceptional refinement.

The 6.2L also makes 460 ft-lb, but doesn't get there til 4100

I'll start by saying I LOVED the performance and fuel mileage of the small diesel (RAM Ecodiesel). So yeah, I considered the 3.0L Duramax Diesel. However, my less than stellar experience with initial cost, reliability, emissions, and actual cost of ownership with the Ram EcoDiesel sent me another direction. I was a guinea pig for one baby diesel, I didn't see a reason to volunteer (much less pay) to be one again... Now, in 4-5 years if the 3.0L Duramax Diesel proves to be reliable and ultimately worth the initial investment, I'll be all in, till then I won't be rolling coal.

IMHO, the way things are going with the EPA and politics in general, I'd be surprised if any of the Big 3 continue to offer a small diesel in a half-ton truck.