2) Target Pressure Reduction At Excessive Airbox Temperature - Rotax 914 F Maintenance Manual

9.5.3.2) Target pressure reduction at excessive airbox temperature

See Pic. 31.
During compression process in the turbo charger the intake air will be heated.
To reduce the risk of knocking combustion at high boost pressure with high
intake air temperature, lowering of the target pressure will start at 72°C
(162°F) airbox temperature. See diagram, Pic. 31.
180
160
140
120
100
80
60
40
20
0
-20
00178
70
Boost pressure reduction will result in a drop of performance e.g. the power
drop can reach up to 10 kW at 80°C airbox temperature.
220
200
180
160
140
120
100
80
60
40
20
0
-20
50
00902
Modification no.
- 3 -
72 74
NOTE: On TCU part no. 966.741 the target pressure reduction
starts at 88° C. See Pic. 31/1.
54 58 62 66 70
Reference
76 78 80
74 78 82 86 90
Pic. 31
Airbox Temperatur [°C]
82
(airbox temperature)
Pic. 31/1
Airbox Tem peratur [°C]
94 98
(airbox tem perature)
Main Date
914 F 1999 01 01
Page
57