Find a better price and we'll beat it!

High horsepower demands a free flowing intake system that is unencumbered by the restrictive stock STi Tumbler Generating Valves. APS's bolt-on Tumbler Valve Delete Housing is a precision machined aluminium housing that replaces the stock Subaru component (which mounts between the cylinder head and the intake manifold/throttle body assembly) - and dramatically reduces the restriction between the throttle body and the inlet valves at high horsepower levels.

Also included in the APS STi Tumbler Delete system are two precision manufactured Throttle Position/Servo couplings. These components are mandatory for continued correct operation of the tumble control drive/feedback system. Without these components, the engine management system will detect a tumbler valve malfunction and throw a check engine light (CEL).

With plenty of room to grow your fuel system, the APS tumblers innovative component not only houses the stock STI injectors, but also has provision for 4 auxiliary Bosch style injectors for high horsepower applications. Thus providing the STi performance enthusiast with the best possible drivability offered by the stock injectors and allows for the additional auxiliary injectors to be utilized only when needed at high power levels.

The auxiliary injectors can be mapped by most aftermarket engine management systems across the entire RPM range. To run auxliary injectors, you must purchase APS's fuel rail system and auxliary injector rails system, both sold separately.

NOTE: Special Order. 4-8 weeks for delivery

FITMENT: Subaru STi 2004-2006 with Side Feed Injectors only