11p Road Speed Engine or Trans, VSS settings?

[immortality]

11p has 2 options for road speed in the ADX, one from the engine and the other from the transmission. Which one does the tune use to determine the actual speed for all the transmission functions?

[immortality]

Not sure what is going on here.

In the 11p bin, it has the following settings.

VSS - Driveline Ratio Constant (Engine Code) = .0232
VSS - Driveline Ratio Constant (Transmission Code) = .0239


The 11p help file has the following,

Vehicle Speed Sensor
The factory code has the driveline ratio hard‐coded for the engine code. This
meant for any change to tyre diameter or diff ratio the PCM would read the
rong speed. There is now a user configurable term “VSS – Driveline Ratiow
Constant (Engine Code).
Note: There are two driveline ratio terms. This is due to the original code using
two software modules, one for the engine and one for the transmission. The
transmission was all in MPH while the engine used KPH. The 11P XDF uses KPH
for both engine and transmission with modified calculations to convert anything
that was previously MPH. However the underlying data stored in the calibration
differs, its only the XDF calculation that makes the ratios appear to be the same,
hence the requirement to still have two ratio items.

Example to setup the vehicle speed:
Set “VSS ‐ # pulses per revolution (Used for both engine and trans code)” to
match the pulses per rev [Factory 4L60E is 40 PPR]
=Set “VSS ‐ Driveline Ratio Constant (Engine Code)” using the calculation “Ratio
(Tyre Rev's per Km x Diff Gear Ratio)/ 0.0357”
Set “VSS ‐ Driveline Ratio Constant (Trans Code)” using the calculated engine
code constant.

Using the above calculation doesn't give a number that resembles anything like the original.

A stock 235/45/17 tire does just over 495 revolutions per Km so if I read the above correct,

(495*3.08)/0.0357 = 42,705.88235294118

Where am I going wrong?

[VK_3800]

I think you're nearly there, the number is 1/42705

[Deuce]

I think you're nearly there, the number is 1/42705

Ahh, very interesting, so my 25.7" tyre plus 3.45 diff should have around 0.0212 code for engine AND trans codes?
Then I can put my PPR code back to 40.

[Deuce]

I think you're nearly there, the number is 1/42705

Well, tried it again today with 0.0212 for engine AND trans code. Plus PPR back to 40.
And the speed reading was bang on for gps (+/-1kph). So I think we will leave it like that and touch over the shift points again at a later date.

Last time I was playing with those codes I think I was leaving the standard 11p split in numbers and moving them up and down as a group and only went around and around in circles. But much better now.

Thank you for your help