hi guys does any one know how to tell if i have a -31 or -34 actuator ? (no markings on the actuator bought it as a -31)i know its uprated but unsure which one it is i can not get my erst to run less than 14psi, or would any one know the "lift" off point of uprated actuators is eg 7psi standard actuator. Thanks ryan.

 

you have a -34 mate. a -31 will run on lower boost.hope that helps.

 

And to be clear, the -31 and -34 are just the last two numbers of the Garrett part number. If your actuator does not have any numbers, then it probably is not a Garrett actuator at all. Might be similar though in force/pressure.
The -31 starts to move at around -7psi of pressure with a progressive spring. The -34 will be around 10psi with a linear spring.

 

just wind the arm out on the actuator a little mrore, this will drop the boost pressure a bit.
i have a -34 spring in my collins actuator and will hold 14psi without any additional bleeding, wind out the rod a bit and this will drop.

 

The pressure you are running now doesnt indicate actuator strength if you are going through a lift pressure multipler such as an amal valve.

 

hi stu thanks for your reply. i started off with the amal valve connected and tried two ecus one superchip and one standard ran down the road and a massive over boost of 1.5 bar with no ecu boost cut limit on either ecu, so went to plan b tested amal valve and it all seems to be working correcty. thinking that the amal valve was faulty my only route of action was to fit a bleed valve now this time no intervention on boost cut on either ecu and wil not boost under 14psi ? so must be amal vavle i thought. so fitted standart actuator wich is soggy as S**T tried both ecus, WITH amal valve STILL 1.5 bar WTF ?? so checked every thing twice connections wires ect..stil no luck so plan c fit bleed valve and uprated actuator with either ecu and wil not run less than 14psi hmmmm. at this point ive just done a rebuild on the engine and i want to run it it and dont wanna damage the enigne so gone back to standard actuator for the time. wen ran in i intend to purchase a -31 and use the bleed valve as i do not trust the amal set up. i know this is a way round the problem but not the right one, any ideas would be a great help, thanks guys. btw both actuators set up using half hole preload. and tested actuators by connteced to a pressure gauge and compresor to check operation.

 

nowt wrong with an amal valve they can give a lot better more progressive boost curve than a bleed valve which ive always thought of as a bodge

 

if you don't want boost, then lengthen the actuator rod as much as possible, so it barely closes the wastegate at all.
that'll keep your boost down for sure.