Positive and negative air

Ok in my rock shox manual it says if i have more negative than positive air the small bump sensitivity will be better. My positve is set at 140 psi so how much more negative do i put in or do people keep them at the same pressure?

plus/minus 5 psi is usual i think

check the manual but i think i recall it saying no more than 15 more in the negative.
if you put too much in you loose travel and it all goes wrong.
also recommended preassure on my sids is too high for my weight.