Haltech E8 - Manual (Page 12)

Haltech E11/E8 Instruction Manual
Coolant Temperature Sensor
The coolant temperature sensor has a solid brass temperature-sensing tip. Refer to the diagram for
physical details of the sensor at the back of this manual. The coolant sensor supplied is an industry
standard component and some engines may already have provision for this type of sensor.
The coolant temperature sensor is designed to screw into a threaded hole and protrude into the engine
coolant stream. For air-cooled engines, the sensor can be embedded directly into the engine block or
used to sense oil temperature.
Locate a suitable position on the engine which gives access to the coolant stream before you drill and tap
the thread. The sensor should be mounted before the thermostat in the coolant circuit. Since most
engines have existing temperature sensor holes, it is often possible to mount the Haltech sensor in one of
these holes. If necessary drain the coolant from the vehicle to fit the temperature sensor then consult the
factory manual on how to purge the cooling system of air and check the engine does not require topping-
up with coolant after the engine has reached operating temperature.
Figure 2 - Coolant Temp Sensor
Inlet Air Temperature Sensor
The air temperature sensor is used to compensate for changes in air density due to air temperature. Cold
air has a higher density than warm air and therefore requires a greater volume of fuel to maintain the
same air/fuel ratio. This effect is most noticeable in forced induction engines. The Haltech ECU will
automatically compensate using the signal received from the air temperature sensor (once the air
temperature correction map is setup and enabled in the programming software).
The sensor should be mounted to provide the best representation of the actual temperature of the air
entering the combustion chamber, i.e. after any turbo or supercharger, and intercooler, and as close to the
head as possible. The sensor needs to be in the moving air stream to give fast response times and reduce
Heat-Soak effects. Be aware in some situations, mounting the sensor into the inlet manifold (especially at
the rear) may case Heat Soak problems.
Once a suitable position has been located for the air temperature sensor a hole should be drilled and
tapped to accept the sensor. Remove the manifold or inlet tract from the engine before this is done so you
don’t get any metal particles entering the inlet manifold, as these will be drawn into the engine and may
cause damage.
Figure 3 - Air Temp Sensor
Note: The Haltech air temperature sensor will read temperatures up to 120° C and temperatures above
this will be interpreted as a fault condition. The air temperature after some turbo and superchargers can
exceed this. If this occurs with your engine you should consider fitting an intercooler to reduce air
temperature and increase charge density.
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