Can someone explain why it cost an extra $100 for the 18 psi wastegate actuator? I am still somewhat new to turbochargers but I am thinking this means the wastegate is going to kick in at 18psi correct? I thought everyone running the fp red was running at least 20 -22 psi and I hear up people up to 28 psi. Please let me know if this means I will not get more than 18 psi of boost and if so how can I increase it? Thanks

 

the spring is loaded to hold at least 18 psi. The rest of the boost retention is done via the ecu.

Its just a stronger spring. I believe the normal one is 12 or 14 psi.

 

18 psi ,means the wastegate actuator is fully open at 18 psi, the ecu adds a duty cycle to the boost control solenoid which bleeds off some of the boost pressure that will then allow higher boost pressure.
you can also use a manual boost control valve that will do a similar job of bleeding off the air to the wastegate actuator.

 

^ basically. the stronger wastegate spring will hold boost longer and limit taper