GFB 5933 Mach 2 Atmosphere Conversion Kit suit GFB# T9103/T9133

To vent the Mach 2 to atmosphere, you need to ensure the piston stays closed at idle, and the recirc hose is plugged. The 5933 Atmosphere Conversion Kit includes a 33mm hose plug to block off the recirc hose, a trumpet to replace the hose outlet on the Mach 2 (not necessary for functionality, but makes the sound louder!), and a firmer spring (part # 6115).

The Mach 2 is supplied with a softer spring (part # 6116) that is suitable for recirculation venting or cars with idle vacuum of 18inHg or less. If the piston stays closed with the existing spring in the Mach 2, there is no need to swap it out. However, if the piston hovers open at idle even with the spring pre-load maxed, the firmer spring in this kit should be installed to prevent stalling or backfiring.

Suits the following applications:

• SUBARU WRX MY06-07 (aka "hawkeye")
• SUBARU STi MY03-07
• SUBARU XT MY05-08 (series II)
• SUBARU WRX MY01-02 (aka "bugeye")
• SUBARU STi MY03-07
• SUBARU STi MY03-07
• SUBARU WRX MY01-02 (aka "bugeye")
• SUBARU WRX MY03-05 (aka "peanut eye")
• SUBARU STi MY08-13