Much more than a bar of boost on the little five is not a good idea, if its std head, carb and turbo then it wont be much quicker, especially on track where the charge temps will rise. But if you are intent on making more boost just use the bleed valve, thats what it is for. If the boost level you desire cant be achieved with the valve, then you will have to tighten (wind in) the actuator rod a few turns, then re adjust with bleed valve