57S-4521 K&N Cold Air Intake Kit, 2012 - 2020 Holden Colorado/ TrailBlazer 2.8L L4 dw300 Sharp corners were avoided and

Sharp corners were avoided and machined as smooth fillets to improve oil flow

Tensioner Pulley (Steel) Oct 2006 - Aug 2012

HP Tuners/VCM Suite scaling figures below

4 x reducer bushings for centring the scraper when using factory main cap studs

The shaft diameter is smaller than the OEM plastic barbell to minimize flow restriction

57S-4521 K&N Cold Air Intake Kit, 2012 - 2020 Holden Colorado/ TrailBlazer 2.8L L4 dw300 Sharp corners were avoided andOVERVIEW The K&N Performance Airbox is designed to dramatically reduce air flow restriction as well as smooth and straighten air flow. Replacing the restrictive factory air filter and air box allows your engine to inhale more air than with the factory air filter assembly. More air means more usable power and acceleration throughout the engine's RPM range. A fully enclosed injection molded air box connects to the factory air intake hose. The removable