APS Blow-Off Valve 
 

 
   

   
Most significantly, it'll kick an STi’s bum good and proper.   

Motor Magazine  

 
 
 

 
   
 
APS High Volume Twin Vent Blow Off Valve

Nothing exceeds like excess and with the APS Intercooled Twin Turbo system for the C6 Z06, this is certainly true when considering the blow off valve system. A blow off valve is a device that releases pressure from the turbocharger when the throttle is released. The turbocharged Z06 has unique blow off valve system requirements particularly due to the twin huge horsepower GT3582R turbochargers specified.  

Twin Turbo - Twin Dual Vent Blow Off Valves

Each turbocharger operates in harmony with its own dual vent blow off valave and 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 1.417" (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 to the standard entry point which ensures the best driveability during cruise conditions and cures the erratic idle and engine's rich condition (on gear changes) problems seen with external single venting blow off valves.  And for high boost pressure levels, the APS twin vent blow off valve continues to vent through to the second stage port. 

bov installed Whilst the APS Blow Off Valves are delivered factory set, further adjustment to the blow off valve operation can be performed through the actuation adjustment screw for an optimum response configuration.
 

The above animation demonstrates the operation of the APS High Volume Twin Vent Blow Off Valve.

  1. Ports Closed - Under open throttle conditions where turbocharger boost pressure is required, the bronze BOV piston is held shut in order to supply the maximum amount of charge air to the engine
  2. Primary Port Open - Under light load conditions where the throttle opening has been reduced or shut, the piston moves partially up the bore travel and opens the primary port to vent charge air back into the inlet tract. This ensures smooth engine operation and alleviates the rich condition and subsequent backfire when utilizing a BOV construction that vents100% of charge air to atmosphere.
  3. Both Ports Open - Under high load conditions where the throttle has been shut, the piston travels fully so that both the primary and the wide mouth secondary ports open to vent the maximum charge air possible. Air vented through the primary port is routed back into the inlet tract. In addition, additional excess charge is air vented through the wide mouth secondary port to atmosphere.