I had a less than ideal spec years ago, rs500 t4, standard head with a pair of bd14 cams, it ran 2.2 bar of boost for 472 hp but the turbo surge was really bad, boost had to be capped to below 1.5 bar below 5600 rpm to stop the surge which killed the torque it only made 350 lbft 🤣😂

i presume my head needed work to flow the air at lower rpms or different camshafts