Marshall

I know its been asked before but can someone quicly remind me how much boost the P20 cell is? The manual says it 2 kg/cm2, which isnt quite 14 psi. How do you tune for over 2.0 kg/cm2?
thanks

rynberg

Boy, you better work on your conversions if you don't want to blow anything up.

2 kg/cm^2 = 28.4 psi

www.onlineconversion.com

Marshall

Yeah but thats Pabs. Pguage = Pabs-Patm which is 28.4-14.7 = 13.7 psi. So P20 should correspond to 13.7psi on a boost guage -or am I way off here? I know this has been discussed before but I can't find it.

Tim Benton

iTrader: (1)

Marshall,

It depends on the absolute value that is in there, if you got it from a tuner. Go in and see what value 180000, 160000, etc it had for pressure value in the cells going down the grid for pressure.
Post something in the PFC section as well
Tim

rynberg

Is this really the way the PFC measures boost? I didn't think so as it makes no sense. The boost reading should be the INCREASE over ambient, not absolute. P20 is the max cell, so I know it doesn't correspond to 13.7 psi.

Marshall

well it does measure it that way (relatively) -otherwise there would be no way to tune for the vacuum side (ie if you ran a straight conversion into kg/cm2 without subtracting Patm, P01 would still be positive pressure). In other words you have a vacuum to boost transition somewhere between P01 and P20 but as Tim said its all relative depending on the cell settings -the PFC manual is a little deceiving here. I think we're both right (ambient is a "0" value somewhere between P01 and P20) but the wording is a little tricky!