If you are beginning to piece together your 2nd gen swap, starting with the intake is logical. All S400 turbochargers share a common 5" compressor inlet which means it's time to upgrade. Modern diesel engines are produced with a 4" intake which means they are inherently incompatible and insufficient for your bigger S400 frame turbocharger. This is where Overland Industries comes in. By utilizing a Commercial Off The Shelf (COTS) program, we were able to source premium quality components at a reasonable price. This 5" Intake System includes a water-resistant pre-filter to help keep large debris and water out of your cleanable 8-Ply 5" air filter. Transitioning down towards the turbocharger is a 5" molded plastic intake elbow with sensor mounting provisions, this attaches to a molded 5" rubber elbow.