The factory turbochargers on the 6.7L Powerstroke trucks have a c-clip style quick disconnect fitting on the compressor outlet. We machine fittings that allow for our hot side charge tube to interface with the factory turbo c-clip. It’s simple, clean and strong. The difference between the two options (one or two-piece) is how we connect our machined fittings to the charge tube itself.
With the one-piece design, we weld our machined fitting to the tube. This creates a cost-effective and robust design, although it limits your flexibility on install. Alignment is critical with the one piece design, so if you have an aftermarket intercooler / turbocharger, or you plan to change variables in the future, those slight shifts in placement will make installing the limited flexibility charge tube much more difficult, or in some cases, impossible. As such, we recommend the one-piece design for stock trucks.
The two-piece design was primarily created to give you more flexibility, which is achieved through the use of an additional silicone coupler connection. Our machined fitting that interfaces with the turbocharger / factory c-clip is provided as a standalone piece. We designed it to end with a standard beaded slip-style connection, allowing us to run a silicone connection right at the compressor outlet to our charge tube. The intercooler-end of the charge tube is identical to the one-piece design, ending in a silicone coupler connection as well. The use of two silicone couplers (instead of one) allows for much more wiggle room, which again really helps if you're doing aftermarket upgrades where the geometry of your components may differ from the factory ones. It also helps if the truck is getting older and the body mounts are sagging, the motor mounts are off, or the truck has been in an accident.
These two charge tube options provide identical performance, and are equally robust. For most customers, we recommend the two-piece design: it is easier to install, and provides the wiggle room necessary for trucks with aftermarket components. However, for stock trucks in good condition, the one-piece design is a solid option, and will save you some money as well.