Increasing Fuel Pressure on an ODBII, single line car

We are fitting a PS1C on a 2001 CLK55. The only thing that is holding us back right now is trying to increase the fuel pressure slightly.

We are going to run about 5 psi at the intake. Based on our conversations with Bosch personnel and other techs out there, they believe that the OBDII, single fuel line setup in the CLK55, should be able to compensate for the boost up to 6 psi without any modifications.

Does anyone know how to increase the fuel pressure on a setup like this? I believe you have to increase the voltage to the pump.

We could make fuel curve adjustments to the ECU and pull back slightly on the timing advance, but were were trying to avoid that.

Thanks,

Chris

Most of those OBD II cars use a pulse modulated pump control. Its not about increasing the voltage to the pump, but increasing the frequency of the pulses. Granted, I guess you could just increase the amount of fuel the pump squirts by increasing the voltage per pulse, but I don't know what range of voltages those pumps can deal with happily.

Is there any way that you could go to a slightly larger injector? That should take care of any fuel problem... obviously you are going to be doing some kind of tuning anyway, that's an expensive motor to guess on with a P1SC behind it, I'm sure you want to play it safe.