The amount of internal air pressure is regulated by nozzle size.
Consult with your TRICON representative or bit manufacturer prior to changing nozzle sizes. TRICON will organize an air test to confirm the correct nozzle size for your specific application.
Nozzle the bit to achieve pressures of approximately 35-40 psi (2.4-2.8 bar) in the drill bit.
Note that cab pressure gauges can read significantly higher than this value. As a rule-of-thumb: the difference between cab and at the bit is 8-10 psi (0.5-0.7 bar).