With its huge capacity the APS blow off valve gives you the ultimate in turbocharger durability and improved turbo response particularly during gear changes. A mammoth 1.375" (34 mm) internal bore size delivers huge capacity and at full piston travel, all ports are fully exposed for maximum blow off volume.The APS twin vent BOV features 30 micron hard anodized, T6 billet aluminum body, low friction bronze piston, all stainless steel hardware including spring and Viton 'O' rings. 

The large primary vent is designed to plumb back to the standard entry point which ensures the best driveability during cruise conditions and cures the problems seen with after market external single venting blow off valves.And for large turbochargers running high boost pressure levels, the APS twin vent blow off valve continues to vent through to the second stage port.Fits: Mitsubishi Lancer Evolution 9

Tech Tip: This is a Bolt on blow off valve for you evo, no expensiveflanges or welding. Can be installed in your driveway with hand tools in lessthen 20 minutes.

Tech Note: EVO9parts has tested many bovs for the EVO 8 and this APSBOV is one of the best performers on the market.