.81 a/r
When do you see full boost with your current setup? 3500 rpm? Later?
My T67 front mount (granted, a different turbo, different location) came with a 0.81 and we needed to go to the 0.96 to get good power. It's fully spooled with 11 psi at 3000 rpm.
Have you done the complete exhaust wrapping thing yet for your STS?

