There are essentially two ways to improve a diesel engines performance, you either change the fuel or air flow. The greater the volume of cold air that flows into the engine, the more oxygen is available to burn the fuel. You want cold air because it is more dense than hot air.
A naturally aspirated engine draws the air from the atmosphere, where as an engine with a turbo uses the engine’s power to increase the pressure of the air.
The turbo sucks air into the engine, through what’s called the cold side, which passes through the engine and out to the hot side of the turbo. As the engine RPMs increase the hot air spins the turbo faster, which sucks more air into the engine.
The DAF comes with a Holset H1C turbo, which has a 50mm inducer with 7 blades, which can produce 25psi. We upgraded to a Holset HX35W, which has a 54mm inducer with 8 blades, and can produce 35psi. The HX40 would have been the bets upgrade but we know from past research it won’t fit in the engine bay.
When investigating ceramic coating the exhaust manifold, I learnt that I could also get the turbo done to match. Bonehead Performance applied a matt black ceramic coating on the hot side, and a Chevy Orange powder coat on the cold side to match the other highlights on the truck.