Why do some actuators have one feed of them opposed to some like mine that have two comming of the unit?

thanks.

Double decker version????

You always have to go one better Spin.......... lol

quick google search finds :

 

Bottom port connected with pressure air hose

Top port for quick release hot air, no pressure control function

Quick release hot air.oh!

dual port actuator helps the wastegate stay closed longer until desired boost level.

Some single port actuators (like the standard actuator) can struggle to get a stable boost or even reach a certain boost at high boost levels, because the exhaust gas pressure forces the wastegate to open.

Conflicting info. Anyone else

Lymon is correct. It's a way of running higher boost with a weaker wastegate spring.

You get round the problem of a single port actuator slowly opening the wastegate as the manifold (boost) pressure rises by using an EVC

(HKS for example). Correctly setup, the EVC will not allow pressure from the inlet mainifold to reach the wastegate until the set pressure

has been reached. Once the set mainfold pressure has been reached the EVC signals the EVC solenoid to open and full manifold pressure

reaches the wastegate actuator. This keeps the wastegate firmly shut until the last moment.

A dual port actuator with both ports utilised mimics the method of boost control using an external wastegate. The top port simply forces the wategate valve closed. Using an EBC in "ext wg" configuraton allows for more accurate boost control. That's the main purpose of them. They do allow for higher boost but you should always specify the actuator spring & preload correctly first & foremost for a suitable base boost setting. I have run GTX2860 turbos with the pressure source to the actuators disconnected and only saw a peak of 1.8bar. A clear mismatch, the actuator springs should have been 20psi.

So Noel do i need to find out exactly what this springs are ment to be set at? Or have i missed the point.