Mitsubishi S4S Service Manual page 53

ADJUSTMENTS, BENCH TEST, PERFORMANCE TESTS
(2) Calculation of corrected power
Multiply the measured brake power or torque by the calculated diesel engine correction factor (see below)
to obtained a corrected value.
Corrected output
=
Correction factor (ac) x Measured brake power
• Atmospheric conditions for test
Temperature (T): 283 K (l0°C) [SOap]
~
T
~
313 K (40°C) [104°P]
Dry atmospheric pressure (Pd): 80 kPa (600 mmHg)
~
Pd
~
110 kPa (825 mmHg)
(3) Calculation of correction factor (oe)
cc
=
(fa)fm
fa: Atmospheric factor fm: Engine factor
(a) Calculation of atmospheric factor (fa)
CD Natural aspiration engine and engine with mechanically driven air charger
fa
=(
~)
•( l )
0.7
Pd 298
@
Turbocharged engine without air cooler (after cooler) or with air-to-air cooler
99 T
fa
= ( _ )
0.7 • ( _ ) 1.2
Pd 298
@
Turbocharged engine with air-to-liquid cooler
99
T
fa
=
(_)0.7. (_)07
Pd 298
(b) Calculation of engine factor (fm)
fm
=
0.036 qc - 1.14
q
CD qc (Corrected fuel supply volume)
=-
r
(z) x (Fuel flow rate gIs)
q
=
(Stroke volume
f)
x (Engine idle speed min-I)
z
=
120000 (4-cycle engine)
r: Ratio of pressure at turbocharger or air cooler to atmospheric pressure
(r
=
1 for natural aspiration engine)
@
Applicable range of engine factor (fm)
37.2
~
qc
~
65 mg/(f-cycle)
• qc
~
37.2 mg/(f-cycle) : fm
=
0.2 (Constant)
• 65 mgl(f-cycle)
~
qc : fm
=
1.2 (Constant)
(c) Range of correction equation use
The range of correction factor (oe) use is as follows: 0.9
~
ac
~
l.I.
If this range is exceeded, indicate the corrected value and record the test conditions on the test record sheet.
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