Cossiep.

This is because we only have a set pressure range we can work to dicated by the pump. We cannot continue to increase fuel pressure past the pumps maximum working pressure for the flow rate we require! (we dont want pump lockout)

As such we are pretty much dicated by a maximum working pressure of between 5.5 - 6 bar on a cossie. If you take a car that runs 2 bar boost you can see that the base setting is going to be in the region of 3.5 - 4 bar which is exactly how all cossies are setup.