Dr. Ickxs

Hi guys.

What is the best actuator to use on a standard S2 engine?
The specs:
Engine is rebuild to original spec. New original Garret turbocharger.
Larger intercooler, K&N panel filter and 2.5" stainless mongoose exhaust.
Hart/diamond/hash ECU, original, not chipped.

I used an old original actuator on the new turbo charger, but it seems the actuator is a bit tired. Starts to open at 0.2 bar (2.9psi)
I only find -18 or -31 actuators beeing sold. But what do these numbers mean? Which should I choose?

Thanks,

Karl @ FPT

-31 will be fine mate, the stronger -34 is for big power builds really.

Loomer

You sometimes can struggle on a -31 as depending on how well the map sensor works in the ECU they can boost cut at 9psi without a chip in them, and the -31 has a 9lb spring, so you have to run next to no preload.
I've had to chip them before just to prevent them clipping the boost cut.