Valving for lighter PGP spring

[Memornix]

I am working on a project that may or may not involve a pneumatic ram cycling my PGP. That being said, I would like to run a lighter spring in the PGP to aid in lower cycling pressure for the ram. To do so I imagine I would need to change or mod the valve in order to get proper velocity and am wondering if anyone can point me in the right direction before I totally bork this thing.

I can buy a new valve if there is a good option, otherwise, I have machine tools.

[Grendel]

I don't think the issue really is the valve but more the transfer tube size being too small.

[XEMON]

The ram is not working against the valve spring, but against the hammer spring. If you lighten the happer spring to a certain point, you'll also have to lighten the valve and expand transfer port and valve body.
How much work do you want to put in?

I have been working on a spring kit for the PGP for the last few months and lightning the valve spring won't give you much effect.
Most pneumatic ram can overcome the pressure of the hammer spring if you have sufficient incoming pressure. Do you have a model selected?