It's not just boost, it's a combination. You could run high boost, but if your tune is crap and you don't make much power, prolly won't lift the head. Jim was making retarded torque, like near 500 ft-lbs. THAT is what lifts the head. Extreme cylinder pressure.
1992 Eagle Talon TSi - sold (POS)
2002 Mustang GT - sold
2002 SVTF - sold
2008.5 Mazdaspeed3 GT - cursed
2003 350Z Track - basically stock, and it runs