2003 Ford Focus RS - sensors question ?

[stevieturbo]

driven vehicle speed shouldnt really be such an average...I guess unless the vehicle is 4wd ?

As the name implies...driven wheel speed should relate only to the driven wheels.

Vehicle speed could be an average of all 4...but more typically would be the undriven wheels where possible.

Exactly what are you using for this driven speed reference as inputs to the ecu ?

Cruising steady speeds it shouldnt really matter though, but if you used say an undriven input, then during wheelspin etc, this would confuse things and the wrong gear could be displayed.

Again, what is drive ratio displaying when driving or logging, and have these values been input correctly ? If so then the gear display should work.....assuming you're viewing gear number on the ecu of course. It will work on Plex too when all configured correctly.

[Jackstrath]

driven vehicle speed shouldnt really be such an average...I guess unless the vehicle is 4wd ?

As the name implies...driven wheel speed should relate only to the driven wheels.

Vehicle speed could be an average of all 4...but more typically would be the undriven wheels where possible.

Exactly what are you using for this driven speed reference as inputs to the ecu ?

Cruising steady speeds it shouldnt really matter though, but if you used say an undriven input, then during wheelspin etc, this would confuse things and the wrong gear could be displayed.

Again, what is drive ratio displaying when driving or logging, and have these values been input correctly ? If so then the gear display should work.....assuming you're viewing gear number on the ecu of course. It will work on Plex too when all configured correctly.

car is fwd, it comes from the gearbox speed sensor so i guess its only the front wheels that are being messured. sadly cant change that unless i add in another sensor on the undriven wheels or figure out how to tap into a ABS sensor with out upsetting the abs

The speed input is purely set up for displaying speed while cruising about on the road, handy to have a speedo.

Il have to look into the drive ratio while driving ,im not sure what it is tho, i might be able to pull up a log from the dyno.

I have it set up on the plex but all it displys is N for neutral?

[stevieturbo]

driven vehicle speed shouldnt really be such an average...I guess unless the vehicle is 4wd ?

As the name implies...driven wheel speed should relate only to the driven wheels.

Vehicle speed could be an average of all 4...but more typically would be the undriven wheels where possible.

Exactly what are you using for this driven speed reference as inputs to the ecu ?

Cruising steady speeds it shouldnt really matter though, but if you used say an undriven input, then during wheelspin etc, this would confuse things and the wrong gear could be displayed.

Again, what is drive ratio displaying when driving or logging, and have these values been input correctly ? If so then the gear display should work.....assuming you're viewing gear number on the ecu of course. It will work on Plex too when all configured correctly.

car is fwd, it comes from the gearbox speed sensor so i guess its only the front wheels that are being messured. sadly cant change that unless i add in another sensor on the undriven wheels or figure out how to tap into a ABS sensor with out upsetting the abs

The speed input is purely set up for displaying speed while cruising about on the road, handy to have a speedo.

Il have to look into the drive ratio while driving ,im not sure what it is tho, i might be able to pull up a log from the dyno.

I have it set up on the plex but all it displys is N for neutral?

Then driven wheel speed should be set from that input, not as an average of all 4.

Drive ratio will tell you what these values should be for the table based on driven speed vs tyre circumference etc entered so all ratios are correct for the gear to be correct.
You dont need a log from a dyno, and doubtful on a dyno it would be correct if you're trying to use some sort of average of all 4 wheels...given 2 probably arent turning.
Again all speed inputs in use need setup correctly. If you have only one, that's still ok...but set it up correctly.

Unless Plex has changed it recently, they always displayed 0 for neutral, although I did ask a few times for this to be changed so maybe they've done that now. I havent updated mine for 3-4 months as havent really used the car much.

Again, you need to see if the ecu is displaying the gear correctly before worrying about the dash assuming you are using the ecu's input for gear data, vs using the Plex to calculate gear position itself from speed/rpm and gearing info you tell it.

[Jackstrath]

yeh im using the syvecs for displaying gear on the plex, the gear used to just be blank for me until i enabled gear position from wheel speed on the dash,

the gauge on the syvecs just says the word neutral no matter what gear or speed im doing, so i think the ratios might be wrong

[TimH]

Have you set the wheel circumference and gear ratios?

To calculate the gear, the algorithm needs road speed, wheel circumference, gear ratios and rpm.

[Jackstrath]

Got it working , the ratios were correct , i had to change the driven wheel speed select to radar and it started working! chuffed! thanks for the help guys!

Just this oil temp issue to have another look at and play about with the launch control settings for a timer rather than wheel speed.

oh and any recommendations for stepper motors for air bypass for anti lag?

[stevieturbo]

A stepper motor would require a lot of ecu outputs, so probably a poor choice.

Does your car not have some sort of idle bypass solenoid already ?

Or go DBW.

[Jackstrath]

Yeh this is the second time DBW has popped up, Iv seen I can get mk2 focus RS dbw throttle BODYS and peddles cheap enough , is it a simple case of getting both peddle and body and then the dbw module that syvecs sells? Wiering pretty self explanatory? Positive, negative, and 2 signal wires ? Plus some calibrations

[TimH]

Most/all DBW setups need 4 inputs (2 from the pedal and 2 from the throttle body) so you'll need 3 spare (1 will be freed up from the existing TPS), so check that you have these available. And a spare ignition output for the DBW H-bridge driver box.

Can't comment on how easy the parts are to fit on your car though.

Then it is indeed "just" a case of doing the wiring and setting it up (videos on Youtube will help you).

[stevieturbo]

Strictly speaking yes for safety and correctness it should have 2 inputs from the pedal, and 2 from the blade itself. Not everyone does that though.

So at a push if you were input limited you could take a little risk.

You can use pretty much any pedal with an analogue output, and likewise the DBW motor itself.

And as Tim says, the help videos are pretty good for configuring the DBW settings for the motor etc, but whether it's simple or not....slightly harder to answer.

I'd say it is relatively easy...but certainly not one of the most simple things to do.