RCM 3 port boost controller kit, with plug and play adaptor.

Direct Plug and play fitment on MY99+ Subaru Impreza WRX/STI/Turbo/GT models.

Essential for any modified Subaru running larger turbochargers and/or higher than factory levels of boost pressure.

Utlising the same Pierburg solenoid unit used by Prodrive in their own 3 port boost solenoid kit found on the WR1 model the RCM 3 Port Boost Control Solenoid kit allows you to raise the cars boost level beyond factory parameters whilst retaining control and improving turbo response. 

What is a 3 Port EBCS and how is it different than stock?

The 3 Port EBCS is a solenoid that does just what the name implies. It controls boost pressure. In a turbocharged vehicle, there are a couple components that make up the boost control system. The wastegate and the boost controller. The wastegate has a spring that is set at a certain pressure and boost is controlled by over pressurizing the spring allowing the actuator to open and bypass hot exhaust gases around the turbine. In order to run more boost than what the spring is rated at, the boost controller will divert pressure and keep the wastegate closed until the desired boost level is reached.

A 3 Port EBCS does this by interrupting the boost signal between a boost source and the wastegate.  It then redirects this pressure back to the intake. Typical OEM boost controllers are of the 2 Port variety and operate by bleeding off this pressure signal between the boost source and wastegate. The bleed method is simple, but it also reacts slower than the interrupt method and with less precision.

Why is it a good upgrade?

The 3 Port EBCS is a good upgrade because with better boost control, you get a more precisely dialed in tune.