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...

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.

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. 

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.  

One of the biggest advancements in turbo design since we first started applying them to diesel engines over 70 years ago has been the invention of Variable Geometry Turbos. These turbos utilize a set of movable vanes on the inside of the exhaust housing that allows the actuator to vary the area in which exhaust gasses can pass through them. This allows the exhaust side of the turbo to increase or restrict the flow of exhaust hitting the turbine wheel. In some designs it also changes the flow direction of gasses hitting the exhaust turbine as you can see illustrated below. 


When restricted, the velocity of the exhaust gasses increases which helps spin the turbine faster than a fixed geometry turbo would. This gives the turbo the ability to spool the turbine and compressor wheel up much better than it normally would even with a low volume of exhaust pressure traveling through the system. This helps to spool the turbo at lower RPMs to create boost where it would normally be lacking. This is why variable geometry turbos (VGTs) are such an advancement. They have the ability to significantly reduce turbo lag and provide much better response and turbo efficiency across a range of RPMs. 

Turbocharging diesel engines is nothing new.  The most basic premise of a diesel engine is the more fuel and air you mix during compression, the more power you get. 

• Wastegate Turbocharger
• Fixed Vane Turbocharger
• VVT/VGT Turbocharger
• Compound Turbocharger 
• Twin Turbocharger
• Dual Scroll Turbocharger

Between 1885 and 1916 a few patent applications were submitted for products that address the general concept of turbocharging, but it was in 1925 that Swiss Engineer Alfred Buchi put the first commercially available turbo on a 10 cylinder diesel engine.  Turbochargers use exhaust gas pressure to drive a Turbine Wheel that is connected to a Compressor Wheel. The compressor wheel forces cold air into your engine. You're using exhaust pressure to create boost pressure. 

Ever wonder what you need to push your stock truck to its limit?  We know the answer, and we created this article for you.  For 600-640 RWHP you will need to keep in mind all the supporting modifications you need to maintain reliability.   

Custom tuning is going to ask your truck to perform at a higher level.  The same goes for upgrading your turbo, transmission, fuel system or any other performance orientate component.  The best way to maintain a moderate level of reliability while upgrading is to address these issues once and do it right!

Here is the list of what you need to make a reliable 600+ RWHP LML with a DPF still on it:

• EZ Lynk AutoAgent 2.0 w/ Support Pack & LSP5 Switch
• LML Stealth 64 Turbo
• 10mm Cp4 Exergy Stroker Pump
• DT550 Built Transmission
• S&B Intake
• Tie Rod Sleeves
• Traction Bars
• Fass 165 Lift Pump
• Beans Fuel Tank Sump Kit
• Edge Insight CTS2 Monitor
• EGT Probe

DT LML Twin Kit: Peak Performance And Driveability

Introducing the DT LML Twin Kit for 2015-2016 Duramax trucks from Duramaxtuner.com!  This kit was designed in-house with Wehrli Custom Fab to give you a product that pushes the limits of power and keeps your EGTs cool.  Let's go over some of the features this product has to offer your 2015-2016 LML.

You use your truck for daily commuting or hauling the family and trailer for a long weekend of camping,  you’re rolling up to your work or that campsite and you notice the LML go into regeneration (regen).  You can’t keep driving as you should because you got a job to do or things to unpack.  You can’t help but wonder what can be done to keep your LML from going into this cycle as often as it does, we’ll get into that in bit, first let’s look a little more at DPF regen. 

The DPF takes essentially 700 miles or 18 hours of drive time to put it to the maximum values of normal calculated mass soot levels, which if you were curious is 44 grams.   Active Regen describes the procedure your truck goes through to burn that accumulated soot.  To do this, fuel is dosed through a 9th injector directly into your exhaust.  Many drivers have noticed a drop in MPG and even potentially a lack of power during regen. 

A popular theory is that if you go through regen less frequently, your MPGs will go up.  So, how can you go through less regens?

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. 

The Stealth 67G2:

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