Diesel Tuner's Blog

Duramax VVT & LML Turbo Comparison – Stock vs STR vs 64mm vs 67mm

[fa icon="calendar'] Jun 10, 2025 9:49:22 AM / by Ben Lawson posted in Duramax Performance, better performance for lly, LLY Mods, lly performance, LLY, Duramax, Duramax Power, LML, LBZ, More Power for my LML?, what are some upgrades I can go to my LML?, LBZ Power, Boost, Turbo, LML Power, Stock Turbo, Stealth 64, Stealth, LML Performance, LMM, LBZ Turbo, LMM Turbo, LML Turbo, Diesel Turbo Options Duramax, Duramax Turbo, LLY Turbo, Stealth 64G2, Stealth VVT, Stealth 64 LML, Stealth 67, Stealth 67G2, VVT

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With so many drop-in turbo upgrades to choose from it can be hard to make sure you're getting exactly what you want, and need, out of a drop-in turbo upgrade for your '04.5-'16 Duramax. Could your stock LLY, LBZ, LMM, or LML turbo be enough to crank out the power you're looking for if you really turned it up?  Do aftermarket replacements really live up to their claims? Today we'll take an in-depth look at what you can expect out of varying levels of drop-in turbo upgrades for your 6.6L Duramax and compare them to what the your stock charger can provide. Below is the data from our in-depth engine dyno testing of a Stock VVT/LML turbo, Stealth STR, Stealth Mach 1, and Stealth Mach 2 turbo. All tests were conducted on a built LBZ engine connected to our Dyno-mite water brake engine dyno.  This empirical data was gathered under real-world circumstances, with a serious effort made to control as many variables as possible for consistency. Installation, instrumentation, and operation of this engine through a gauntlet of tests that took several weeks.

 


Turbo and Test Descriptions

            

Dyno Engine: The platform that we will be using for this test is a 2007 6.6L LBZ Duramax that received the following upgrades before testing:

• Custom tuning
• S&B Cold Air Intake
• 100% over injectors
• 10mm CP3 pump
• Head studs
• Alternate firing order cam
• Upgraded pistons
• Upgraded crank shaft
• Upgraded connecting rods

These upgrades were necessary to be able to handle the power levels that we pushed this engine to during the testing of all 4 of these turbos. 

Testing: We performed three tests to gauge the overall performance of each turbo in comparison to each other. Obviously the bigger the turbo, the more top end power. But what about all the other factors that go into creating that power like drive pressure, EGTs, air/fuel ratio, etc? What about in towing conditions and all-around drive-ability? The first test that we will present is the "Max Power" test which is your traditional dyno and power test.  This test will provide a general comparison in terms of the difference in power that these different turbo options can produce. The second test presents spool up data and will give a good visualization of the difference in drivability and turbo lag that each turbo can provide. Finally our "Tow Test" is the ultimate data provider, providing insights on key data points including EGT's, drive pressure, air/fuel ratio Ect...


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A 700hp Emissions-In-Tact LML Duramax: The Time Bomb Build Breakdown

[fa icon="calendar'] Oct 9, 2024 7:15:00 AM / by Ben Lawson posted in Duramax Performance, duramaxtuner, Duramax, Emissions, Duramax Power, LML, Emisssions Intact Tuning, More Power for my LML?, what are some upgrades I can go to my LML?, LML Tuning, Emissions Intact, LML Power, clean sweep, LML Performance, Emissions Equipped, Build, build thread, LML Turbo, 600HP LML, Stealth 64 LML

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David Schaefer’s 2015 GMC 2500HD Denali, known as "Time Bomb," is a remarkable achievement in the world of diesel performance. With a stunning 700 horsepower while maintaining full emissions compliance, this truck is a testament to what can be accomplished with thoughtful engineering and high-quality components. Let’s break down this comprehensive build, exploring the features that make it special and how they come together to create a never before achieved driving experience. 

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The #1 Upgrade for Emissions In-Tact Diesel Trucks: Emissions In-Tact Custom Tuning

[fa icon="calendar'] Jul 19, 2024 8:00:00 AM / by Ben Lawson posted in Duramax Performance, lly performance, Duramax, Duramax Power, Emissions Intact, LML Performance, towing performance, L5P, diesel performance

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Adding power to your diesel, whether it be a  Cummins, Powerstroke, or Duramax, can be a fun and rewarding experience. However, when it comes to upgrading an emissions in-tact truck options can sometimes be limited and results can often be underwhelming. But that doesn't mean you have to suffer with poor performance, complicated upgrades or the cost of removing your emissions components! Emissions in-tact custom tuning is a solution that will not only blow you away in terms of performance and ease of installation but it can also improve the performance gains from other aftermarket upgrades that may not be pulling their weight as they stand.


Unleashing Hidden Potential Without Compromising Emissions

Emissions In-Tact Custom Tuning is specifically designed to optimize the performance of your diesel truck while keeping all emissions systems fully operational. This means you can enjoy improved power, torque, and fuel efficiency without the need to remove or tamper with your truck’s emissions equipment.

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Why The DT44 Is One Of The Most Popular 2.8L Duramax Performance Upgrades On The Market

[fa icon="calendar'] Jun 11, 2024 4:18:52 PM / by Ben Lawson posted in Duramax Performance, Duramax, 2.8L, colorado, Duramax Turbo, LWN

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Blow The Tires off Your L5P With These 4 Upgrades!

[fa icon="calendar'] Sep 5, 2022 3:30:00 PM / by Ben Lawson posted in Duramax Performance, Duramax Power, Turbo, TCM Tuning, L5P, L5P Tuning, Upgrades

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With the L5P being the newest Duramax engine on the scene it's also one of the best performing right out of the box. Making 400hp and 850 ft-lbs of torque when tested on our dyno. This iteration of the Duramax engine has been redesigned in all the right ways. From a thicker crank shaft, to a more advanced turbo, and pistons that can handle more load and heat than we've ever seen come in a stock Duramax engine before. Not only do we get improved performance but we also get an engine that can handle way more power than it left the factory with. Which means with bolt on upgrades alone you can raise the horsepower way beyond stock without having to do any upgrades to the internals of the engine. We've seen L5P's pushing up to 900ph on the stock internals. Even trucks still equipped with emissions systems can gain about 300hp and 500ft-lbs of torque with just a few bolt on upgrades. Today we will show you what upgrades you want on your L5P to make the biggest difference for the least about of money. So if maximum performance is what you’re looking to get out of your L5P this article is for you.

 

Here are the top four L5P upgrades!

  • Tune
  • Transmission
  • Turbo
  • Intake 

 

Tuning Options for L5P

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Don't Delete Your 2017-2020 L5P Duramax DPF!!!

[fa icon="calendar'] Aug 26, 2020 10:15:00 AM / by Justin Tyson posted in Duramax Performance, Duramax, Duramax Power, DPF ON, DPF Delete, L5P

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Do you need to delete your L5P DPF?

We've all heard from forums and numerous outlets that deleting your DPF system is the way to go these days. What we never see backing these claims is data and tests. There is plenty of personal stories around a failed sensor or even the occasional DPF failure. However, once data starts fueling the debate on whether to delete or keep your emissions intact you may change your mind of what to do. 

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Your 750HP Build @ DuramaxTuner.com

[fa icon="calendar'] Jun 16, 2017 9:45:00 AM / by Paul Wilson posted in Duramax Performance, DuramaxTuner.com, Duramax Power, shop, Estimate, 750hp, Build

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Get your truck the horsepower you need:

It's summer time and that means trucks are out sled pulling, towing, and getting worked! It also means you are more likely to be considering your trucks next upgrade (or repair).  

For the diesel owner who wrenches on his own truck the cost per horsepower is lower and his acceptable margin of error is inevitably higher.  In other words, it's cheaper but if something goes wrong there is only yourself to blame.  Many enthusiast thrive on this and only trust themselves or a few select others to  work on their truck.  The reality is however, that many diesel power fanatics don't have the time or skill level to tackle the bigger jobs - They just want to drive them!   Read on to see what things to consider in selecting a shop to do work on your truck.  

Here are some examples of truck builds we have done in the past:

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3 Things Your 600HP LB7 Build Must Have

[fa icon="calendar'] Jun 14, 2017 8:50:00 AM / by Paul Wilson posted in Duramax Performance, dsp5, EFILive, Duramax Power, LB7, SPADE, Fass, Lift Pump, CTS2

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Your 600HP Duramax Needs These 3 Things:

There are a lot of part combinations that can take your 2001-2004 Duramax to 600HP.  No matter what selections you make, there are 3 things you have to include if you want to keep your truck healthy and making power.

Here are some other articles about LB7 trucks:

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6 Things To Know Before Upgrading Your Duramax Turbo!

[fa icon="calendar'] Sep 9, 2016 10:00:00 AM / by Paul Wilson posted in Duramax Performance, LLY, duramaxtuner, LML, LBZ, Turbo, Stock Turbo, Stealth 64, Turbo Wheel, LB7, Stealth

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Stock Duramax Turbo Upgrades!

Duramax owners are generally proud of how their stock turbos perform.  They spool quickly, run hard and are capable of over 500 RWHP (once you tune it and make a few supporting modifications to handle the power).  However, after driving your truck around 520 RWHP for a while, the addiction will creep in and you may find yourself shopping for more power.  We all do it!  For some, it may not even be about more power, it may be about EGT control under load, or it may just be the factory turbo had an issue and needs to be replaced.  If you are anything like me, you will not want to replace it with the factory components if there is an upgraded, after market, charger available. 

 


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Drop-In Duramax Turbo Options

[fa icon="calendar'] Sep 7, 2016 2:17:28 PM / by Paul Wilson posted in Duramax Performance, Duramax, Duramax Power, 2013, 2014, 2016, 2011, 2015, LML, How to program my LML, More Power for my LML?, what are some upgrades I can go to my LML?, Turbo, 2012, LML Tuning, LML Power, Stock, Stock Turbo, Stealth 64, 2017, Stealth

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Drop-In Duramax Turbo Options

In the old days, there was no such thing as a "drop-in" turbo.  You pretty much had to buy a turbo that was designed for a different application and convert it to run on your Duramax.  Meaning the requirements for installation included several custom fabricated pieces to make it work.  

As technology in the diesel performance industry has advanced, our options for parts have expanded.  No longer do we have to use semi turbo's and roal coal to make power.  Now with the common rail injection system and variable vane turbo advancements there is a real need to find a turbo that makes more power than stock, while retaining all the benefits of a stock turbo. 

Benefits of a stock turbo:

  • Quick Spooling 
  • Clean installation
  • Reliable
  • Serviceable by any dealer or reputable shop
  • Requires no custom fabrication

Download Duramax Turbo Specifications

However, they do lack peak power, and peak power matters!  When looking for which upgraded unit to replace the stock turbo, we recommend matching the replacement as close as possible to the desired power level to minimize compromising drive-ability.  Any extra capacity you buy in peak for performance will cost you low end response.  Example: Looking to make 650rwhp? Buy a turbo that can just barely squeak out 650rwhp, do not buy something that's good for 850rwhp because it will drive poorly a light load. 

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