That map is about the only thing that you will find out there, that has been published. But to be honest, if you're curious about being able to push that turbo any further, I'd highly recommend you start looking at your back pressure. Not knowing your back pressure or which turbine housing and compressor cover it has, it's really a crap shoot for us to say yes or no you can turn it up more. However, with that said, the P-trim turbine wheel has been pushed harder, as well as the 70 comp wheel.
Having the capability to monitor your back pressure before the turbo, would tell you if your combination could take more boost or not. Typically, customers will mount a pressure gauge or pressure sending unit just before the turbo and log their back pressure. The general rule of thumb we use is, once you've hit a 2:1 back pressure to boost pressure level, you're pretty much done. And with our very restrictive 3-bolt style turbine housings, those limits come up very quick on a purpose built motor. An example of this would be, if you are running 30psi of boost at the intake, and your back pressure is 60psi, you're done. But if say your back pressure was below 60psi, you technically could run more boost. The other method is alot less complicated, as you increase boost at the track, the point where the car stops making more mph could also be the limitation point. If the tune is there to take the extra power that is. I would be hesitant to push a 70 P-trim turbo much past 35psi. At least back in the day when I ran that turbo, 35psi was my limit. That was with an older LT70-1, P-trim with .85 A/R.
What turbine housing and compressor cover does your turbo currently have?
Hope some of this helps.
Patrick