i think 10 psi is the limit for a standard ecu a chipped ecu will have this limit removed i personally would not give it more boost by messing with the actuator without adding more fuel as well, these are tempremental engines that need setting by someone who knows what they are doing. i would reccomend you take it to a reputable tuner like nms or msd it isnt as dear as people think (usually less than 200 quid) for a set up and the difference will be like night and day withe the added plus of it being safe