Wastegate spring
 

Last year I was running a 8 or 9 psi spring, with a TurboXS two stage manual boostcontroller. Low boost setting at about 10psi and high boost at 13psi. As some may know I bulit a new engine this winter, going from stock compression to around 9,2:1. I therefor expect to need to increase the low boost to get the same numbers, and of course go even higher in high boost setting (but I don't know how high yet). Will I be fine with the same wastegate spring, or do I need to change it to a stiffer one? I would really hate to change it as it's a pita, but IF I need to, this is the time to do it... The boost controller is a TurboXS high performance dual stage boost controller if that has anything to say.
Any input?

how much boost do you want to run. Id get a spring for what the MIN boost you wanna run then use the controller to go up from there. Ive seen 20+ out of a 8-10psi base spring with no issue before though

From what I was told by my tuner. Good rule of the with a spring is you can run roughly twice the amount of boost the spring is. So for a 8lb spring roughly 16-18psi max. Now if you want to run more and keep a smaller spring run a 4 port solenoid so the top and the bottom of the wastegate are controlled seperately and not Tee'd.

It is a general rule of thumb that you may be limited by double the spring rate, but I have often seen some make more than double. It is dependant on exhaust pressure. The higher your EMAP the less you will get out of the spring.

Hmm. Well, the problem is I don't know how much boost I'm going to run yet. But I know it will be more... So maybe I'll change it to a slightly stiffer spring if I have the time. I'll see what I manage to squeeze in with the time I have! :)