you are correct sir also 14.7 psi is 1 atm and that equates to 101.4 KPA which equats 760 torr (mmHG)2K2CamaroSS said:yep 1psi = 6.89 kpa
So Turner427 12.5psi = 86.18kpa which is right where you say yours is reading
first off, a barometer is measure in mmHG (millimeters of mercury) not in inches, as a side note mmHG is out torr is in (same thing but a torr is named after the man who invented it, like watt, pascal, newton, ect....). also what is a measure of autometer? and just for kicks boost isnt exactly a measurement.....its a term. boost is a general term for any compressed gas in the engine thats over 1 ATM. boost is measure in something, ATM, psi, mmHG ect.johnkb8 said:what does "IN HG" stand for, i know autometer, i know psi, i know boost, but dont know what "IN HG" means on there
1 ATM is a bit misleading as it seems to imply that the gauge measures against a set pressure. (pressure at sea level under standard conditions is the definition of an atmosphere). Your boost/vacuum gauge will measure Pounds per Square Inch Gauge (PSIG) over or under the local pressure which may be higher (Death Valley) or lower than the standard atmosphere.nice_n_lo_silverado said:.its a term. boost is a general term for any compressed gas in the engine thats over 1 ATM. boost is measure in something, ATM, psi, mmHG ect.
Interesting question. In a n/a engine, the cylinder pressures will be lower when there is a lower ambient pressure as there will be less air mass drawn in on the intake stroke, thus less cylinder pressure on the compression stroke (both dynamic and static). In a forced induction motor it is a bit more murky. I suppose whatever type of relief valve was used to limit the upper boost limit would, for lack of a better phrase, 'pop off' at lower absolute pressures if the ambient pressure was lower than 1 ATM.nice_n_lo_silverado said:this is true, but isnt a cumbustion chamber always at a set variable of pressure readings? never blew X and above Y (when working properly) if the engine were moved to higher and lwer altitudes i wouldnt think that the chambers pressure would be any different, if at higher elevations it would be making boost than.
correct me if im wrong ion this but this is what i thought....i knew?