Gear Detection

[Matt Dunn]

I see how the ECU can determine gear from wheel speed and RPM's,

but can you get it to determine gear from a variable resistor?

We have a gear position sensor in the gearbox,

but we dont have a wheel speed sensor at this stage?

Can it be connected to an analogue input and done that way?

 

 

[Jurgen Biggelaar]

Hi Matt.

Unfortunately not.  To calculate gear, it must have the required PWM signal (speed) vs. RPM.  Pretty much as simple as that.  There really isn't a way to fudge it either.  Cheers.

Jurgen

[Darryl Curran]

so what is actualy required to set up gear Detection? i want to change to ecu controlled boost and use gear detection as well, on S7 RX7.

[seized]

You need a speed sensor on a driven wheel. Then you can enter the gear ratios yourself, or let it learn them.

 

[Matt Dunn]

That is fine.  We will run a rear wheel speed sensor anyway and will let the ECU calculate the gear for ECU functions,

But  we will wire the AIM dash directly to the gear sensor for readout on the dash. We have been trying to avoid doubling up on sensors by wiring almost everything to the ECU and then sending it via can/rs232 to the AIM dash.

 

[Jurgen Biggelaar]

Hi Matt.

I hope I am not missing the point completly here, but if the ECU will be aware of the speed input from the rear, and it knows RPM, then it by default it will know which gear you are in (when calibrated correctly). 

Your statement 'We will run a rear wheel speed sensor anyway and will let the ECU calculate the gear for ECU functions' is what has thrown me.  Why would you just not use the RS232 data to the dash for it's display if this contains 'gear' already?

Not that I can promise anything here, but what gear box/sensor brand/model are you using, as we may want to add it as a function someday.  Also, if you have the output resistance for each gear, this would help us a great deal in implementing such a feature.

Jurgen

[Cameron Moore]

Hi Matt,

Do you have details on the output of the gearbox? eg resistance for each gear?

-Cameron