A.4.g. TDC Tooth Setup Software Adjustment Parameters
So, you took a lot of time to install your trigger wheel, and now you realize that you didn’t get the
trailing edge of the 11
th
tooth to align with the center of the magnetic sensor with the engine at TDC #1.
What to do?
The WinTec software features a TDC setup parameter that allows users to manipulate the TDC
point for the trigger wheel. There are two adjustable parameters:
Change DFU “A” Trigger Wheel TDC
Change DFU “B” Trigger Wheel TDC
For all but the odd-fire applications, the adjustment is only present for the DFU “A” TDC. The
default setting for DFU “A” TDC is 11, signifying TDC alignments with the 11
th
tooth. If you are aligned
with the 13
th
tooth at TDC, change this number to 13. Several late-model Bosch-equipped applications use
our 60 (-2) tooth trigger wheel, but come from the factory with a different TDC tooth alignment. Typically,
these setups are referenced to the 14
th
tooth for TDC, but you MUST confirm this on your application,
since Bosch used a few different offsets through the years.
Odd-Fire applications have the ability to move the TDC reference for the second DFU (using the
parameter “DFU “B” Trigger Wheel TDC”). This allows the user to define the odd-fire ignition split that is
present on the engine. Refer to
Section C.5
to determine the proper settings for this value.
Some applications may require more “mechanical timing” to compensate for large, high-overlap
cams. Assuming the crank sensor is aligned with the 11
th
tooth at TDC, this can be done by entering a
value for the “Change DFU “A” Trigger Wheel TDC” that is LESS than 11. Each tooth less than 11
represents 6 degrees of advance that is added to the Ignition Advance Table.
Some applications may require less “mechanical timing” (some rotary users may wish to do this).
Assuming the crank sensor is aligned with the 11
th
tooth at TDC, this can be done by entering a value for
the “Change DFU “A” Trigger Wheel TDC” that is MORE than 11. Each tooth more that 11 represents 6
degrees of retard that is subtracted from the Ignition Advance Table.
If an odd-fire engine has the trigger wheel installed incorrectly, and the DFU “A” TDC parameter is
changed to compensate for the error, the “DFU “B” Trigger Wheel TDC” parameter needs to be
manipulated in the same amount. As an example, if the TDC for DFU “A” is at 11 and is moved to 10, the
TDC for DFU “B” would need to be moved from 16 to 15.
The following pages outline the various situations that can be addressed through the TDC software
parameters.
Situation A
Problem:
Incorrect trigger wheel alignment results in undesired mechanical timing.
Solution:
With the engine at TDC #1, find the trigger wheel tooth that is aligned with the crank sensor. Enter the
number of this tooth into the TDC Tooth Alignment Parameter. The timing will be shifted to make the
Ignition Advance Table accurate.
Method:
The software will automatically RETARD the timing when a number GREATER THAN 11 is entered into
the TDC Tooth Alignment Parameter. The timing will be automatically ADVANCED when a number
LESS THAN 11 is entered.
Situation B
Problem:
The engine needs less mechanical advance, and the crank sensor is aligned with the 11
th
tooth.
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TECgt Manual Version 2.0
- Page 19 -
©2008 Electromotive, Inc.
