Diesel Tuner's Blog

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...

The newest turbo from Calibrated Power is definitely raising the bar for drop-in turbos.

When looking at replacing your stock turbo there's a lot to take into consideration; How you use your truck, your current needs, and the future goals for your Cummins.  With the success of the Stealth 64 for 5.9L Cummins, the team at Calibrated Power looked at how much more we can push the envelope. So, what can the 3rd Gen Stealth 67 get you?

Stealth 64?  Stealth 64G2? Stealth 67G2?

You finally got the okay from the wife on spending that tax return, you're thinking about upgrading the turbo on your 2001-2004 LB7.  Like any well educated Duramax owner you go to DuramaxTuner.com to check out everything you can on the Stealth turbo, but you're still wondering which is right for you.  

Now you may have the urge to simply pick the turbo with the highest peak power.  Maybe your thought process is to go immediately at the cheapest price.  To be honest, no matter which way you go, each Stealth turbo is going to be better than the stock charger. However, there are a few things we would recommend you consider before making your buying decision. It can help you save money and time in the long run, so let's dive into which suits you best.

There are a few things to consider before picking a new turbo for your LB7:

1.  What size injectors do you have?
2.  Are you going to build the engine?
3.  What is your ultimate HP goal and what do you plan on using the truck for?

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)