Well it sounds like you have a car with a turbo and if so you shouldent
go boost crazy , personaly i cant tell you what it can take because i
dont know what you have but you should consider these factors.....if
you add more air to the engine you will have to add more fuel as well
if not you will be running too lean and a higher combustion temp will
be created and you could melt your pistons and/or valves not a good
thing but it all comes down to how much boost you want to create.