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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Breaking Down the Stealth Turbo Line: STR, Mach 1, and Mach 2 – Which One Is Right for You?

[fa icon="calendar'] Feb 21, 2025 7:00:00 AM / by Ben Lawson posted in Cummins Turbo, Turbo, Bolt on turbo, LBZ Turbo, LMM Turbo, LML Turbo, Diesel Turbo Options Duramax, Diesel Turbo Options Cummins, Duramax Turbo, LLY Turbo, Turbo Upgrades, L5P Turbo

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When it comes to turbochargers for diesel trucks, Stealth Turbos have made a name for themselves by offering performance, reliability, and quality upgrades across the board. Whether you’re driving a 6.6L Duramax, 6.7L Powerstroke or a 6.7L Cummins, Stealth turbos can provide solutions for a multitude of different needs and wants—from stock replacements to high-performance setups. In this blog post, we’ll break down the key differences between Stealth’s STR, Mach 1, and Mach 2 line's of turbochargers and help you decide which one is the best fit for your driving needs.



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Stock Duramax Turbo Specs and Information

[fa icon="calendar'] Jul 31, 2023 8:00:00 AM / by Ben Lawson posted in LLY, Duramax, LML, LBZ, Turbo, Stock Turbo, LB7, LMM, LB7 Turbo, LBZ Turbo, LMM Turbo, LML Turbo, Duramax Turbo, LLY Turbo, L5P, L5P Turbo

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Over the years, GM has changed a lot regarding the turbos they use on Duramax engines. Not only have they changed manufacturers a handful of times but each RPO has its own unique measurements for key components. This can make it a headache when trying to track down exactly what the measurements of your stock turbo are. Luckily we've compiled this list of stock Duramax turbo specifications along with other helpful information so you can get a good idea of what you're already working with before you dive into the sea of turbo upgrades these trucks have to choose from. However, while some turbos may have the same peak power output, the size and shape of specific components can affect things such as exhaust gas temperature, drive pressure, and turbo efficiency range.  

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Stealth 67G2 LB7: The Ultimate 800 HP Duramax Turbo! 

[fa icon="calendar'] Mar 26, 2018 10:00:00 AM / by Justin Tyson posted in Turbo Wheel, Stealth, LB7 Turbo, Bolt on turbo, LBZ Turbo, LMM Turbo, LML Turbo, Duramax Turbo, LLY Turbo, Turbo Upgrades, Stealth 67, Stealth 67G2

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Single, Drop-In, 800 HP, LB7 Turbo:

When you're looking for the ultimate Duramax turbo, everything really depends on what caters to your wants and needs for your truck.  This turbo was created with diesel enthusiasts such as ourselves in mind. We asked what everyone wanted in a larger turbo and the Stealth 67 G2 is what we came back with. This new addition to the Stealth line is superb and fits in the family of our in-house designed, industry leading turbos. Let's delve into what this beast can accomplish. 

LB7 STEALTH 67G2 DETAIL SHEET

 

The Stealth 67G2:

  • Quick spool up
  • Big power
  • Great daily driver
  • Models available for 2001-2016 Duramax (LB7, VVT, LML)
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STEALTH TURBO PRICE UPDATE

[fa icon="calendar'] Oct 23, 2017 2:44:13 PM / by Paul Wilson posted in LLY, LML, Cummins Turbo, LBZ, LML Power, Stock Turbo, Stealth 64, LB7, Stealth, LML Performance, LMM, LB7 Turbo, Bolt on turbo, LBZ Turbo, LMM Turbo, LML Turbo, Diesel Turbo Options Duramax, Diesel Turbo Options Cummins, Duramax Turbo, LLY Turbo, Turbo Upgrades, LB7 Turbo Upgrade, 640HP LB7, Stealth 64G2, Stealth VVT, Stealth 64 LML

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We have lowered our MAP pricing on the Stealth 64 Turbo:

Calibrated Power, home of DuramaxTuner.com, has ramped up in-house production of the Stealth Turbo line.  This added capacity and volume of turbo production has provided an opportunity to lower MAP pricing on all Duramax models and allowed the Cummins 5.9L Stealth 64 to be a low price and top quality leader in it's category. 

Our Stealth 64 Turbo's are:

  • Made in the USA!
  • Upgraded, Drop-In Replacement!
  • Quick Spooling with Big POWER!
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What goes into making a top quality turbo

[fa icon="calendar'] Mar 24, 2017 11:44:46 AM / by Paul Wilson posted in Cummins Turbo, Stealth 64, LB7 Turbo, LBZ Turbo, LMM Turbo, LML Turbo, Diesel Turbo Options Duramax, Diesel Turbo Options Cummins, Duramax Turbo, LLY Turbo, Turbo Upgrades

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Manufacturing the best turbo possible takes top quality parts, a scrutinty to detail and multiple QC checks.

DuramaxTuner.com is excited to be manufacturing turbochargers in-house.  It has given us a chance to dial in what it takes to produce the highest quality aftermarket turbo for the Duramax and Cummins trucks.  

               

For those of you thinking about upgrading your turbo in the future, or if you are just a diesel performance nut, we thought you would like a behind the scene look of what goes into our Stealth turbo manufacturing.  

Other Turbo Articles:

Drop-In Turbo Option for LLY, LBZ and LMM

LB7 Duramax Turbo Upgrade!

LML Stealth 64 VVT, 620 RWHP Drop-In Turbo

5.9L Cummins Turbo, Towing and Performance

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