Difference of Color Balance in RGY and RGB

[Mille]

I'm planning to upgrade my 650 Red to fully use my >300 mW of 532 green and obtain a good balance.
At the moment i have >300 mW in both red and green: how much red i need to get?
and above all i'm wandering if there's difference in Power ratio for every color to obtain a perfect white in RGB, or a perfect Yellow in RGY.
So if i obtain a good yellow mixing 532 and 650, then i need only to add 473 blue to have white?... or i need to upgrade green and red too?

I hope i was enough clear to explain the question
I just woke up

[Doc]

According to Tocket's fantastic Chroma program; 900mW of 650nm red (or 500mW of 635 red) gives a perfect yellow with 300mW of 532 green. You would then need to add around 400mW of 473nm to obtain an almost perfect white.

[ElektroFreak]

Just today I ran across this pdf from CNI. It contains their recommendations for power levels of various wavelengths for proper color blending in an RGB system. It might help you out.