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.  

The ten-speed Allison 1000 is substantially better than previous Allison models we have seen come in Duramax trucks. Known for its superior towing performance, excellent fuel economy, and outstanding reliability. It utilizes some of the best technology GM has ever produced. Its reputation for excellence was earned largely because of the advanced electronic control systems provided by the TCM (Transmission Control Module).

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. 

New Product Release: L5P Stealth STR Turbo
Calibrated Power was the very first custom tuner to tune the L5P Duramax platform and have been building custom turbos and tuning for over 15 years. We know exactly what these trucks respond to and need to get the best performance out of them. Now with their newest addition to the L5P performance market, the L5P Stealth STR. We've used what they have learned about the L5P platform to provide a drop-in stock turbo replacement that offers improved performance and reliability at a similar price to a stock turbo replacement. 

Here are the features: 

• Airflow that Supports 650hp
• Brand New parts and electronics
• Custom Billet Compressor Wheel
• Designed and spec'd by DuramaxTuner

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 

What's an RPO? Crucial Duramax Information!

This article will help you understand what an RPO is, how to find yours and when it will be needed.  An RPO or Regular Production Option is a GM-specific code, made up of 3 characters, that helps the manufacturer specify what configuration of options has been or needs to be applied to a vehicle. This can include anything from paint color to powertrain options. For Chevy/GMC Duramax trucks each type of engine can be signified by a different RPO code.

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. 

When it comes to modifying your diesel truck, we all know that tuning is the best bang-for-your-buck. Tuning is not magic, it is a science. It takes time to understand all the intricacies and tables that come with it. All tuning is about is recalibrating your factory ECM, with that we’re able to work with factory parameters and modify them to what your custom tuning needs.

We know you 2017 - 2020 L5P owners have been beckoning for an actual turbo upgrade, well we have one for you today!

It's what every Duramax lover is talking about right now!

As you’re well aware the L5P Duramax is all diesel enthusiasts are talking about right now.  It’s not unwarranted though as tuning is slowly becoming more an actual thing rather than a hope.  Now that HP Tuners have unlocked the possibilities, Duramaxtuner is wanting to know more.  While getting there hands on the ECM and doing intense R&D.  It would be a good thing to discuss what exactly comes with the L5P. 

If you’ve been following the Duramax world, you know that these trucks change every few years.  The LML ran from 2011-2016 and gave way to this new truck, the L5P.  The new L5P comes stock with higher horsepower numbers than it’s predecessor, but what exactly is different with this Duramax?  Let’s take a look at three major components this truck brings to the table.