Power differences between the LB7 thru to the L5P.

[turbovan]

Not sure if this goes here, but please move if needed.

Wondered this for years but never asked, lol. I drive a lot of different diesels due to my job, and of course, notice the LBZ to the LML have a lot more power compared to the LB7 and LLY-all stock but of course, all bets are off tuned.
I used my friends bone stock LML to tow my trailer and it acted like it wasn't even there.
Is this just a tuning thing or is there more to it. Basically, they are virtually the same, except some use ficm's, some don't and different style injectors.

Thanks for answering.

 

[darkness]

Lb7- 300/520
Lly- 310/605
Lbz- 360/650
Lmm- 365/660
Lml- 397/765
L5p- 445/910
I think that’s pretty close. A lot of complaints in the lml with dead petal it seems.

EDIT by chevy1925

 

[turbovan]

Lb7- 300/520
Lly- 315/520
Lbz- 360/605
Lmm- 365/650
Lml- 397/765
I think that’s pretty close. A lot of complaints in the lml with dead petal it seems.

250 ft/lbs lly vs lml is huge.
Mine tows ok but with the LML, not even a comparison.

I did notice the dead pedal but you get used to it. He now has it deleted and tuned with a small tow tune and holy crap, its an animal.

 

[PureHybrid]

I think the LLY was 310/605. Lbz was rated same as LMM I thought too

 

[2004LB7]

The biggest difference is in the tuning.

The nozzles pretty much get smaller through each generation. The pressure did go up a little on the LBZ and above so that helps

The LB7 had a fixed vane turbo and the rest are variable. Is the LLY turbo still the largest? Or did the LML or L5P use the same or larger size?

 

[TheBac]

Lb7- 300/520
Lly- 315/520
Lbz- 360/605
Lmm- 365/650
Lml- 397/765
I think that’s pretty close. A lot of complaints in the lml with dead petal it seems.

I would add L5P - 445/910 and edit the title, because you know someone will ask sometime.....

Im pretty sure the actual LLY was 310/520. The 315/605 rating was the "LLY" (derated LBZ) in 2006.

 

[Chevy1925]

LBZ - 360hp / 650tq
LMM - 365hp / 660tq

They slightly uprated the lmm back then

 

[Chevy1925]

@darkness I made changes to your OG post, hope you don’t mind

 

[Hoser]

Hard parts improve, cooling improves, pressure and nozzles improve, and therefore you can tune up the power. Obviously it’s about the whole package from engine, transmission, cooling, and brakes, and as all those things improve over time, the capabilities greatly increase. If you think the LML does great towing (which it does) wait until you pull with a ‘20+ L5P with the 10-speed. . . . .

 

[hntngkd]

I would add L5P - 445/910 and edit the title, because you know someone will ask sometime.....

Im pretty sure the actual LLY was 310/520. The 315/605 rating was the "LLY" (derated LBZ) in 2006.

2024 L5P bumps up to 470hp and 975lb-ft

 

[turbovan]

Ok, so forget the trans etc, and I believe turbo sizes are very close, so why the huge difference from LB7 to LML. Can the LB7 be a tune away from LML, but then you can tune an LML and be way more, probably around 850. Is the turbo that small on the LB7? The others?
LLY, LBZ capable of 750 ft/lbs stock with a tune?

 

[TheBac]

Ok, so forget the trans etc, and I believe turbo sizes are very close, so why the huge difference from LB7 to LML. Can the LB7 be a tune away from LML, but then you can tune an LML and be way more, probably around 850. Is the turbo that small on the LB7? The others?
LLY, LBZ capable of 750 ft/lbs stock with a tune?

See post #9.

 

[turbovan]

See post #9.

That doesn't explain the huge power difference. Internally, virtually identical, injectors, all around the same size, all use the CP3 pump except LML, turbo sizes pretty close.
My last post said ignore rads, transmissions.

 

[2004LB7]

That doesn't explain the huge power difference. Internally, virtually identical, injectors, all around the same size, all use the CP3 pump except LML, turbo sizes pretty close.
My last post said ignore rads, transmissions.

Your not getting anywhere close to 850 hp on the LML with just a tune. You kinda max out a little over 500. Maybe 550 if pushed to the limit. That's not much more then the LB7 pushed the same way. Most of the gains are in the tuning. The rest of the changes are for reliability and emissions

 

[turbovan]

Your not getting anywhere close to 850 hp on the LML with just a tune. You kinda max out a little over 500. Maybe 550 if pushed to the limit. That's not much more then the LB7 pushed the same way. Most of the gains are in the tuning. The rest of the changes are for reliability and emissions

Above says LML, 397/765, so you're telling me a tune won't add 100 ft/lbs?
Not talking HP,


Again, are any of the previous platforms capable of 750-800 ft/lbs with just a tune? Like I said, just trying to understand when all the engines are virtually identical.

 

[2004LB7]

Above says LML, 397/765, so you're telling me a tune won't add 100 ft/lbs?
Not talking HP,


Again, are any of the previous platforms capable of 750-800 ft/lbs with just a tune? Like I said, just trying to understand when all the engines are virtually identical.

Yes. 800 ft/lbs is not that hard with tuning only on any generation

 

[JoshH]

This is the most complete list I found with a quick google search.​

​

Duramax Horsepower & Torque Figures by Model Year​

Model Year(s)​	Horsepower​	Torque​	RPO Code​
2001 - 2002​	300 hp @ 3,100 rpm​	520 lb-ft @ 1,800 rpm​	LB7​
2003​	300 hp @ 3,100 rpm​	520 lb-ft @ 1,800 rpm​	LB7​
210 hp @ 2,750 rpm​	520 lb-ft @ 1,600 rpm​	LRY [1]​
2004​	300 hp @ 3,100 rpm​	520 lb-ft @ 1,800 rpm​	LB7​
310 hp @ 3,000 rpm​	605 lb-ft @ 1,600 rpm​	LLY, auto trans​
300 hp @ 3,000 rpm​	520 lb-ft @ 1,600 rpm​	LLY, manual trans​
210 hp @ 2,750 rpm​	520 lb-ft @ 1,600 rpm​	LRY [1]​
2005​	310 hp @ 3,000 rpm​	605 lb-ft @ 1,600 rpm​	LLY, auto trans​
300 hp @ 3,000 rpm​	520 lb-ft @ 1,600 rpm​	LLY, manual trans​
210 hp @ 2,750 rpm​	520 lb-ft @ 1,600 rpm​	LRY [2]​
300 hp @ 3,000 rpm​	520 lb-ft @ 1,600 rpm​	LRX [2]​
2006​	310 hp @ 3,000 rpm​	605 lb-ft @ 1,600 rpm​	LLY, auto trans​
300 hp @ 3,000 rpm​	520 lb-ft @ 1,600 rpm​	LLY, manual trans​
360 hp @ 3,200 rpm​	650 lb-ft @ 1,600 rpm​	LBZ​
250 hp @ 2,500 rpm​	460 lb-ft @ 1,600 rpm​	LBZ, van only​
310 hp @ 3,000 rpm​	605 lb-ft @ 1,600 rpm​	LBZ, medium duty only​
300 hp @ 3,000 rpm​	520 lb-ft @ 1,600 rpm​	LRX [2]​
300 hp @ 3,000 rpm​	605 lb-ft @ 1,600 rpm​	LPD [2]​
2007​	360 hp @ 3,200 rpm​	650 lb-ft @ 1,600 rpm​	LBZ​
250 hp @ 2,500 rpm​	460 lb-ft @ 1,600 rpm​	LBZ, van only​
365 hp @ 3,200 rpm​	660 lb-ft @ 1,600 rpm​	LMM​
300 hp @ 3,000 rpm​	520 lb-ft @ 1,600 rpm​	LRX [3]​
330 hp @ 3,000 rpm​	620 lb-ft @ 1,600 rpm​	LYE [3]​
2008 - 2009​	365 hp @ 3,200 rpm​	660 lb-ft @ 1,600 rpm​	LMM​
250 hp @ 3,200 rpm​	460 lb-ft @ 1,600​	LMM, van only​
300 hp @ 3,000 rpm​	520 lb-ft @ 1,600 rpm​	LRX [3]​
330 hp @ 3,000 rpm​	620 lb-ft @ 1,600 rpm​	LYE [3]​
2010​	365 hp @ 3,200 rpm​	660 lb-ft @ 1,600 rpm​	LMM​
250 hp @ 3,200 rpm​	460 lb-ft @ 1,600​	LMM, van only​
2011 - 2012​	397 hp @ 3,000 rpm​	765 lb-ft @ 1,600 rpm​	LML​
335 hp @ 3,100 rpm​	685 lb-ft @ 1,600 rpm​	LGH [4]​
260 hp @ 3,100 rpm​	525 lb-ft @ 1,600 rpm​	LGH [5]​
2012 - 2016​	397 hp @ 3,000 rpm​	765 lb-ft @ 1,600 rpm​	LML​
260 hp @ 3,100 rpm​	525 lb-ft @ 1,600 rpm​	LGH [5]​
2017 - 2022​	445 hp @ 2,800 rpm​	910 lb-ft @ 1,600 rpm​	L5P​

[1] Power option, medium duty engine calibration for Kodiak/TopKick models only; based on LB7 engine platform.
[2] Power option, medium duty engine calibration for Kodiak/TopKick models only; based on LLY engine platform.
[3] Power option, medium duty engine calibration for Kodiak/TopKick models only; based on LMM engine platform.
[4] Electronically de-rated for chassis cab applications; based on LML engine platform.
[5] Electronically de-rated for Express/Savana van applications; based on LML engine platform.

copy and pasted from here: https://www.dieselhub.com/duramax/6.6-duramax-diesel-timeline.html