Photo 2/22 | 001 SDPs Compound Turbos | Here’s the rather crowded engine bay in Micah Thomas’ 2.8L Duramax-powered ’16 Chevrolet Colorado. It’s hard to look at this and think there’s a way to add another turbocharger in here!
Photo 3/22 | 002 SDPs Compound Turbos | Removing the factory air-intake system clarifies the viewpoint significantly. One of the things we noted is the fact that there doesn’t appear to be any good place to actually mount a second turbocharger.
Photo 4/22 | 004 SDPs Compound Turbos | The stock variable-geometry turbo serves its purpose dutifully under normal conditions, but when the workload gets heavy or thoughts turn to performance, Screamin’ Diesel Performance of Port Angeles, Washington, has created a compound-turbo system to give it some help.
Photo 5/22 | 008 SDPs Compound Turbos | SDP’s owner Scott Helpenstell relocates coolant lines in the engine bay. Moving lines, the tank, and some items under the hood is key to making this setup work.
Photo 6/22 | 009 SDPs Compound Turbos | This is the custom-designed banjo fitting that seats beneath the oil-pressure sensor on the block. This banjo fitting is the lynchpin in making sure the turbocharger has a good oil source, as there are no ports on the passenger side of the block.
Photo 7/22 | 011 SDPs Compound Turbos | SDP fabricates and tests the TIG-welded coolant tanks in-house.
Photo 8/22 | 013 SDPs Compound Turbos | Scott says there is one part of the installation process that may intimidate some people, and that is drilling the block for the oil-drain line from the turbocharger. As long as the installer does not rush the job, there’s nothing to fear.
Photo 9/22 | 015 SDPs Compound Turbos | Here’s the finished oil-drain line at the back of the block, complete with a threaded fitting and high-quality braided line.
Photo 11/22 | 018 SDPs Compound Turbos | The kit ships with a BorgWarner S300SX-E turbocharger. While this one is powdercoated blue, almost any color imaginable can be created for the turbo and tubing.
Photo 12/22 | 019 SDPs Compound Turbos | Check out the flange thickness on this pipe. Thick flanges are a good indicator of the strength of this system. They ensure even clamping and resistance to flexing and deflecting.
Photo 13/22 | 024 SDPs Compound Turbos | Scott completes some of the preinstallation work.
Photo 14/22 | 025 SDPs Compound Turbos | It may not look like much installed, but this bracket is something Scott and the SDP crew are very proud of. Why? In many ways, this turbo-mounting bracket is the most important part of the system, as it is subjected to incredible load and stress from the engine.
Photo 15/22 | 029 SDPs Compound Turbos | Old hot-rodders used to say, “Chrome don’t make it go.” But in this case, the SDP 2.8L Duramax compound-turbo system looks like a million bucks and it supports significant power.
Photo 16/22 | 030 SDPs Compound Turbos | Scott attaches the drain line to the bottom of the turbocharger before installing it on the engine. Setups like this include detailed instructions for a good reason.
Photo 17/22 | 032 SDPs Compound Turbos | Displacing only 2.8L, the little Duramax makes respectable power in bone-stock trim. But, as we get closer to completing the installation, we can’t wait to see what, if any, the improvements are when we’re done.
Photo 18/22 | 034 SDPs Compound Turbos | With all the major work completed and the kit 90 percent installed, this photo provides you with an idea of how the layout works. We cannot get over how well this system is packaged.
Photo 19/22 | 035 SDPs Compound Turbos | SDP offers optional equipment such as 40mm Turbosmart wastegates.
Photo 20/22 | 037 SDPs Compound Turbos | With the compound-turbo system fully installed and the engine cover back on, everything looks great in blue powdercoat. If you’re really sneaky, have it done in black, and some diesel enthusiasts might miss the fact that you’ve bolted another turbo on your little rig’s engine!
Photo 21/22 | 043 SDPs Compound Turbos | After completing the installation, we took the truck for a drive. What a difference 100 more horses make on the 2.8L Duramax! The truck is like a completely different animal! The driving manners are factory-perfect, the EGT stayed happy the entire time we were cruising, and we’re now completely addicted to the additional power and torque.
Photo 22/22 | SDPs Compound Turbos Dyno Chart | The dyno sheet shows the massive increases in horsepower and torque over stock. It’s important to note that the very impressive numbers we saw (305.12 hp/543.81 lb-ft) are 100 percent valid. The gains are pretty much beyond the threshold of performance the 2.8L Duramax engine’s stock connecting rods can support for any significant amount of time. The 295.34/503.62 was achieved with a 100hp tune. While custom ECM calibrations are optional (and require engines upgraded with Carrillo rods), the base 2.8L Duramax compound-turbo kit is shipped with All-In Truck Performance’s tune that yields about 260 hp, a calibration that’s adequate for daily driving and towing, which safeguards your engine’s internals.