a4mayo

Hello, I am new to these forums so forgive me if I do something wrong. I am in the process of purchasing a 2003 A4. Then engine has been swapped with a 2.7t V6 from a 2000 A6. Also the engine has a stage 2 tune done to it. The owner says that currently the clutch will slip with around 18psi of boost with K04 Hybrid Turbochargers. I am wondering how can this be corrected or fixed? I understand that possibly the transmission is worn down and may need to be replaced but if that is not the case is it possible (this may be completely wrong) to just lower the psi? Would this fix the problem if it is not the clutch itself?