Q: What is a diverter valve and what does it do?
A: A diverter valve, also referred to as a "pop off valve", "blow off valve", "boost re-circulation valve", "air/boost bypass valve" is designed to re-circulate the boost pressure that gets built up in the intake manifold in between shifts. The valve at idle (under vacuum) will remain open allowing the air to circulate freely through the intake to the turbo (s) fresh air side. As soon as the the throttle is cracked, ie: the accelerator pedal is moved, the valve will be forced shut stopping the re-circulation of intake air to the turbos and allowing all the boost pressure to enter the motor.
Q: Why should the OEM valve be replaced?
A: The OEM valve is what is commonly known as a diaphragm valve. This valve has been around since the mid 80's and has always been a very problematic part that typically wears out within the first 6 months of operation. An improperly working diverter valve will cause multiple problems. First of all, a improperly working or defective valve will cause boost loss. We have seen a 7-9 HP gain on the dyno on a small displacement motor just by replacing a worn out OEM valve with our Billet valve. Second, in between shifts when the valve is suppose to open to re-circulate the built up boost pressure, if it is defective and cannot open, the built up manifold pressure will "stall" the compressor of the turbocharger causing it to rapidly slow down which can cause turbocharger failure. This "stalling" of the turbocharger will also increase turbo lag in between shifts and reduce power. In addition, the Mode DV will flow 10% more CFM of airflow over the OEM valve.
Q: What makes the EVO valves Better than the Original?
A: The Mode valve is precision CNC machined from billet aluminum. It utilizes a solid billet piston and twin Viton O-rings. All internal components are lubricated with the highest quality RED LINE high temperature synthetic grease for a lifetime of trouble free use. Our custom wound piston spring is designed to react quicker than the OEM unit for quicker boost response and more power. The Mode valve comes with a LIFETIME Warranty.
A: The OEM valve is made of a thin wall injection plastic. The heat of the engine will warp and distort the plastic which causes failure. The internal rubber diaphragm is very susceptible to failure from the heat and constant open and close movement. Rubber will dry out and crack which causes the valve to loose the ability to hold vacuum, thus failing. The weak OEM spring is very slow to react which causes a delay in closing, thus leaking valuable boost pressure and slower boost response.