The Forge direct replacement blow-off valve is designed to be a more durable and performance oriented valve than the OEM unit. The OEM valve is suitable for stock boost levels for a period of time, however, once boost pressure is raised, and after prolonged use, the stock valve will no longer be adequate. Raising the boost output of the vehicle will have a number of effects on the OEM valve. First and foremost, the additional boost pressure will quickly exceed the capacity of the OEM spring to keep the valve closed under higher boost levels. Since you cannot change the springs in the OEM valve, it cannot be adjusted for higher boost levels. Secondly, the additional heat generated by the increased boost will quickly deteriorate the OEM rubber valve diaphragm, which will also lose strength with repeated oscillations.
- 1.5T non Si/Si