We all know the turbo on the EVO pumps out 19.5psi max boost.

My question is

is it measured in psia (pounds per square inch, absolute) or pisg (pounds per square inch, gauge) ?

psia:
full vaccum = 0psi
pressure at sea level = 14.7psi = 1 atm

psig:
full vaccum = -14.7psi
pressure at sea level = 0psi = 1 atm

I want to buy an industrial pressure gauge just for testing purposes, they are dirt cheap, about 15 bucks for a +/- 1% accuracy gauge. i need to know what range.

Cali_EVO

It is gauge pressure.

huhu.....d00d...you listen in physics class waay too closely!

0psi = normal atmosphere pressure at sea level.