Adjusting the Spring Preload
In order to adjust the spring tension on the COBB Tuning BPV, adjust the set screw in the top of the BPV body.
1) Loosen the jam nut using a 13mm open end wrench.
2) Using a 4mm Allen key, turn the screw clockwise to increase spring tension, increase the chance of compressor surge and make the BPV vent to air slower. This will also cause the BPV to vent
later when you lift your foot off the throttle.
3) Turning the screw counter clockwise will decrease the spring tension, decrease compressor surge and make the BPV vent faster. This will also cause the BPV to vent sooner when you lift your
foot off the throttle.
NOTE: Adjusting the spring tension does NOT adjust the amount of boost the BPV will hold. In order to adjust the amount a stiffer spring will be needed.
Bypass Valve Maintenance
It is recommended that every time you change your oil you inspect your COBB Tuning Bypass Valve to make sure the piston is still moving freely. You can do so by unbolting the BPV from the vehicle mounting flange and pushing on the piston. If you can feel some resistance, it is advised to remove the piston from the body and clean and re-grease the piston, we recommend ARP Ultra Torque Fastener Assembly Lubricant, P/N 100-9911, but any moly-based grease will work fine.
Disassemble the COBB Tuning Bypass Valve
In order to remove the piston, unbolt the base flange from the body using a 3mm Allen key. Depending on the BPV model you have, this may be 5-6 socket head cap screws. When removing the piston, be careful to not cut the O-ring. If your O-ring is damaged, you can contact COBB Tuning for a replacement.
Reassemble the COBB Tuning Bypass Valve
To reassemble the BPV, push the piston back into the body, so that the piston does not protrude from the body. You can hold the piston at that point by placing your finger over the vacuum connection.
Place the base flange onto the body and re-clock the flange. Secure the flange with the 5-6 socket head cap screws, depending on the model, using a 3mm Allen key.