you guys with prochargers,what size engine do you have,which procharger unit are you running and how much boost are you making?im mainly wanting responses from pump gas users.

502mag mpi
M-3 Procharger
5 1/2psi with 4 1/2 pulley and 30 pitch prop.

572
M-4 Procharger
13 lbs on 93
MEFI

what horsepower does your 572 make

509 MPI, M1, 5-6lbs

540 w m-3 sc, with 3.85 pulley I dynoed at 12-13 lbs of boost on 92/93 octane pump gas (1057 hp), run 14 lbs with 20% race gas with 3.70 pulley (1115 hp). With these smaller pulleys it makes boost EARLY and FAST too if you lean on it anywhere above 3000-3200. It also made about 10-11 psi with 4.00 pulley and just over 1000 hp, Smitty

smitty,what would you concider maximum boost with 93 pump gas?

IF a Prochargerd marine motor has EFI, afr's verified/tuned on water at wot, aluminum heads and compression close to or around 8-1 along with 75-80 MAX degree lake water for innercooler 12-13 lbs is easily reliable, I have ran that kinda boost for quite a while and haven't hurt a motor yet, Smitty

12 or 13 is what i was thinking,that is what i run with my 8.3L whippled 588s.

Had, 540, M4, 10 lbs, fast efi, Boat was sold from person I sold it to. He or I did not have any motor problems.