I have APS ST and just put in the HKS EVC boost controller. My question is am I suppose to get rid of the preload on the actuator spring? Right now I left the actuator preload as it was before and tested out the boost controller. Well, it's acting funny. If boost is gradually and slowly built from 2000rpm to 6000rpm on 4th gear, It's overboosting. But if the boost is built quickly from 3500rpm to 6000rpm boost controller seems to work. My guess is that if the boost is built slowly, actuator's spring preload is resisting the HKS EVC boost controller. Any help will be appreciated.