RomRaider

First of all I want to thank everyone here that has put all this time and effort into making a community tuning solution for this ecu. I have been using romraider to remove different factory emissions and safety stuff as I swap a s52 into my e30 but I have come across a problem with the vehicle speed sensor. On the e30 it comes from the diff and is processed by the cluster into a 9 pulse output. On the e36 it receives the speed from the right rear wheel speed sensor which is a 48 pulse output. is there anyway to change this in the ecu so that it sees the correct speed? the reason this is important to me is because I want to run the "launch control" 3000 rpm cut but it keeps cutting because its not reading a high enough speed

Could you adjust the axis for whatever the e30 sensor outputs?

I don't know what increments the ecu sees as far as mph does it see in 1 mph increments or less?

VS is calculated as VS_SEG_T_MES (must be >3) * 3600 / VS_FAC (word value from 0166h partial = 6185, so you can experiment with this!!!) result forced to be between 0 and 255. this is for ms412.

Wow I need to do a lot of research, I didn't understand any of what you posted, unfortunately, other than the equation.
but yes ms41.2 is what I am using

There is a speed sensor in an E36 rear diff. How do you know the MS41.2 code is not using that and using the right rear wheel sensor instead?

Do you have a wiring diagram for how the vehicle speed is routed in an E36?

Here are two links that are good at explaining it:
http://www.r3vlimited.com/board/showthread.php?t=285584
http://www.r3vlimited.com/board/showthread.php?t=264748

people wire e30 speed signal to pin 9 x20 which goes to the DME on pin 15 x6000 "right rear wheel speed" this seems to work but is off by a factor of 5.3333

I have interpreted this equation (VS_SEG_T_MES (must be >3) * 3600 / VS_FAC) as follows

-VS_SEG_T_MES is the amount of pulses during a given interval measured by the sensor
-*3600 the above is measured in pulses per second this is a conversion from seconds to hours (miles per hour)
-VS_FAC is the factor (based on the amount of pulses) that I need to change in order to fix this issue

OK reading through. In the meantime, does your instrument cluster read the correct speed?

I'm in the process of adding this calibration factorto the definitions so you can change this easily in RR.

yes it does

It would be awesome to have a way to correct for this, instead of messing around with the rev limit vs speed tables to "make it work"

Try this attached file. I added a value called "Vehicle Speed Correction (ECU)" in the "Limiters" section for the 24KB version of MS41.2 thanks to the info provided by Alec.

Please report on the ideal value to be used for these fairly common swaps.

Awesome Thanks! I believe the value for the e30 should be 1160 I will be back with results

Yeah, that was my guess as well. 6185/5.3333.