I been running 1.4 bar with water injection for some time on pump fuel. I have recently moved on to 50/50 water methanol mix and got a chance to do some testing today at 1.77 bar it goes like absolute stink. I would never of thought a few years ago of running 1.77 bar on pump fuel.

 

I always felt it was more about how much POWER you can make on pump gas, not BOOST. Boost pressure aside, if you have 450 to 500 max rwhp thats IT. maybe thats at 15psi, maybe 22psi, all depends on turbo size, engine porting, manifold work etc.