trying to figure out the "ata" gauge

[Kurfurst]

Originally Posted by bDAWg

hi all
could someone provide a quick and simple explanation of what the ata gauge in the Bf-109 is actually indicating?...is it manifold pressure or boost or are the 2 the same thing?

Its the boost/manifold pressure (same thing) gauge, expressed in atmospheres. 1 ata (= 1 kg / sq.centimeter) is equivalant to 0 lbs/sq.inch, ie. normal ambient air pressure (German boost gauges measure absolute pressure, British ones relative under/overpressure compared to normal pressure.

IIRC 1.7 ata boost (max. boost of later war DB engines) was equivalant to +7 lbs sq. inch, but our DB 601A engine has max. limit of 1.35ata (1.45ata for 1-min WEP), and a corresponding RPM of 2400 (3000/min allowed for 30 secs).