Wastegate Spring Question

[BoostedRBSX]

I need to raise my boost and am using an HKS Standard Waste gate, currently it has a spring around 10lbs. I wanted to order a spring around 15lbs. They offer one that is 14.2lbs but no one can get it. Is there any other springs that will fit this waste gate or is there any thing else I can do to raise the boost? Any help would be great as I am waiting to get the car tuned but need to set it at the right amount of boost. Thanks!

This is an image of what it looks like:

[ashibah83]

you could always install a boost controller, i think most boost controllers allow you to double the spring setting.