[v8volvo]

Welcome to the forum!

Which problem are you trying to solve? Are you saying the boost pressure is too high and you want ideas on how to reduce it? Or are you saying that the engine doesn't have enough power even with all that boost?

If you're concerned about excessive boost pressure, check and make sure the larger hose on the turbo (going from the compressor housing to the wastegate actuator) is connected and not leaking. Stock boost pressure is ~10psi (=0.7 bar) for the non-IC motor so that is what you should see, assuming you installed a stock D24T turbo and have the wastegate hose hooked up.

If your concern is insufficient power at this boost setting, then your next step should be to install a turbo pump, which will give you the boost-responsive fueling you need to make use of that extra air. Intercooler will be important too if you plan to continue running elevated boost pressures. And, of course, all your basic "Stage 0" maintenance and engine condition factors (e.g. engine timing, valve clearance, compression, fuel and air filters, headgasket, etc) all need to be in good shape in order for the engine to perform at its best and stand up to the additional fuel and air you're planning to feed it.

An alternative to putting on a turbo pump, you could turn up the fuel on your stock non-turbo pump, but you'll suffer terrible smoke until the boost comes up, which is hard on the motor, other drivers behind you, air and water quality, etc. At most I would only do this just as a temporary experiment to see if it performs the way you want it to with some additional fuel -- it would not be a good permanent solution.