Haltech Platinum Pro 350z - Manual (Page 37)

User Manual – Haltech 350Z
9. T
UNING A
C
AR BY
VE
AND THE
S
PEED
-D
ENSITY
C
ALCULATION
9.1 Setting up the Parameters
Before tuning the VE table, it is very important that you set all the supporting parameters and tables as accurately
as possible, otherwise your VE table will not calibrated correctly and you will lose many of the advantages of this
tuning method.
1. Load source – Select MAP.
2. Manifold Pressure Source – Choose Internal or External senor.
3. Sensor Calibrations – Check that your Air Temp Calibration Table is correct. If External MAP sensor
is selected, then also check your MAP sensor calibration table corresponds to your MAP sensor.
4. Engine Capacity – Check that your engine capacity value is correct.
5. Injector Flow Rate – Check your injector flow rate table and adjust to suit your injector.
6. Injector Dead Time – Check your injector dead time table and adjust to suit your injector.
7. Target AFR – Check your Target AFR table and adjust to your desired AFR for the given engine
operating point.
9.2 Tuning the VE table
To calibrate the VE table, a calibrated Air/Fuel ratio meter can be used to measure the resulting Air/Fuel Ratio
for a given VE and comparing it to the Target Air/Fuel Ratio table.
If the measured Air/Fuel Ratio is richer than the targeted Air/Fuel ratio, then the VE value in the table at that
engine speed and manifold pressure is too high.
Similarly, if the measured Air/Fuel Ratio is leaner than the targeted Air/Fuel ratio, then the VE value in the table
at that engine speed and manifold pressure is too low.
Increasing the VE value results in richer mixture, lowering the VE value results in a leaner mixture.
The aim of calibrating the VE table is to make the measured AFR match the Target AFR table. When they match,
the VE value in the VE table is a good representation of the VE of the engine for that operating point.
Do not use the VE table to tune mixtures to values other than what is in the Target AFR table. If you wish to
have a richer or leaner mixture for a given engine operating point, then alter the Target AFR table once the VE
table is calibrated.
9.3 Advantages of using VE & Speed-Density
Once the VE table is calibrated to the engine, then any of the other parameters can be changed to affect fuelling.
The advantage is that if the desired AFR changes for a given operating condition (MAP and RPM), then this can
be altered in the Target AFR table and the AFR at that point will move toward that new target. It may not
precisely land on the target due to any error in any of the calibrations of the sensors or VE table, but it if the
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