Limiting peak torque with boost rpm control 2JZ

Hey legends

Im wanting some feedback on tuning some more power from my 2JZ powered S15 silvia.

it’s setup for Roll racing and a bit of drag.

Its currently at 655whp @23psi on e85, all supporting mods and a 6266 precision turbo.

570ft lbs at 5000rpm peak torque, as it is now.

I’m wanting to increase the Hp but without increasing the peak torque any more. Ideally I would like to keep my duty cycle on my boost solenoid exactly the same up to the existing peak torque @5000rpm and then just after that start increasing the solenoid duty cycle (increase boost) to bring up the “torque fall off” and potentially keep 570ft lbs flat across the entire rpm range(within reason).

Obviously the hp from 5250rpm through to 8000rpm would increase as a result.

The idea is to protect my gearbox and driveline a bit whilst still maximising my setup as it.

Brand New R154 gearbox (600ft lbs they start to fail)

just leave the boost alone before the peak torque and increase the boost duty cycle above that. doing it on the dyno should be a nice simple task.