With the huge air flow capacity of the turbocharger utilized in the Lancer, the unique APS High Volume Twin Vent Blow Off Valve delivers unsurpassed venting performance, excellent driveability and crisp turbocharger response in on/off throttle applications. A blow off valve is a device that releases pressure from the turbocharger when the throttle is released. It ensures that the pressure shock load on the turbocharger compressor is minimized and encourages the turbocharger rotating group to continue spinning during gear changes. This ensures that when the next gear is selected and the throttle re-applied, the turbocharger rapidly produces high boost pressure and strong torque.

With large turbochargers, releasing pressure from the turbine compressor wheel when the throttle is snapped shut is critical not only for turbocharger response, but for turbocharger longevity. A huge volume of air must be passed through the blow off valve as soon as the throttle is closed.

Most blow off valves have limitations in their design that inhibit the level of performance demanded by APS. Piston/bore diameter and venting ports are often too small and surprisingly, most will not fully expose the exhaust ports when fully opened.

APS designed the APS high volume twin vent blow off valve specifically for the Lancer in high power states of engine tune.

A mammoth 1.417" (36 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 aluminium body, low friction bronze piston, all stainless steel hardware including spring and Viton 'O' rings.

The large primary vent is designed to plumb back into the inlet tract and ensures the best driveability during cruise conditions. More importantly, the APS BOV cures the problems seen with after market 100% external venting blow off valves. And under spirited driving conditions with the turbocharger running high boost pressure levels, the APS twin vent blow off valve continues to vent through to the second stage port in order to expel the maximum amount of charge air possible.

Fine adjustment to blow off valve operation can be performed through the actuation adjustment screw for optimum configuration.