with stock internals on a B18B1 you can push around 8 psi safely and with good maintenance 10, but if you dont know your ins and outs of forced induction, you should stay around 8. That'll only put at you about 190whp or so.....it'll be fast....but not forced induction fast if you know what i mean. When upgrading look to replace, pistons, rods, piston rings, sleeves, camshafts (if you want better top end), valves, valve springs, retainers, thicker gaskets, ignition, spark plugs, spark plug wires, injectors, fuel pump, fuel pressure regulator................you get the idea. I kinda went to the extreme but, no sense in half-assin' something