Single Vs Dual Port Actuator

SINGLE PORT ACTUATORS

Function: Boost reference signal is supplied to one side of the diaphragm and moves the piston in one direction to open the wastegate. Only mechanical spring pressure is used for the return stroke / holding wastegate closed.

Application: Ideal for basic boost control including via manual boost controller (MBC) or electronic boost controller (EBC)

Advantages - simple plumbing & basic functionality

Disadvantages - Heavily reliant on spring pressure to control boost. Typically requires a significantly heavier spring than a dual port for the same boost pressures, narrower range of boost control and less precise.

DUAL PORT ACTUATORS

Function: Boost reference signal is supplied to both sides of the diaphragm for more precise control of the wastegate in two directions - opening and closing. Spring pressure is pneumatically assisted for the return stroke / holding wastegate closed

Application: Particularly well suited to applications with higher boost levels, high exhaust backpressures or oversized wastegates. Typically used in conjunction with an EBC for the ultimate in boost control.

Advantages - Controls the diaphragm bidirectionally, allowing more precise boost control and superior response. Typically a softer spring than a single port actuator is required for any given target boost pressure, providing a greater range of boost adjustment pressures for any given spring installed

Disadvantages - (To take advantage of the secondary port) Added complexity, more plumbing and must be used with an EBC

Tech tip: Dual port actuators give you more flexibility and tunability but can also be run as a traditional single port actuator - just leave the lower actuator port vented to atmosphere.