Individual wheel speeds.

[k4nnon]

Hey all LinkG4X PnP for usdm evo 9. As the title suggests, Im wanting to input individual wheel speeds to my link. Do I need to individually wire each wheel speed sensor into the ecu and then configure everything? Or this already a supported feature that i just havent set up properly. I have my vehicle speed set up through the oem trans speed sensor and the car does have oem individual wheel speed sensors on all 4 corners, I just dont see how to get these reading in the link, or if i need to hardwire them all with their own inputs. If anyone has information on how to do this i will greatly appreciate the help as always.. Thanks!

[Link2ThePast]

I'm not sure how it is for the Evo but on my car, I had to splice into each abs/wheel speed sensor since my dash only gets an average wheel speed value. If yours is anything like mine, you'll have to do the same to get all 4 into the ECU individually.

To do that, you first have to check if the speed sensors are hall or reluctance sensors. I don't have experience with hall sensors but, on my car, the abs/speed sensors were reluctance (just two wires). 

If yours are reluctance, you'll need to buy two of these; one for the front and one for the rear: https://sirhclabs.com/product/vr-to-hall-sensor-converter-dual-channel/

This converts the sine signal to a square wave used in hall which the ecu likes. Just splice into the existing abs/speed sensor wiring and then hook them up to the inputs of that board. Each sensor will get it's own +/- input on that board, don't mix them. The outputs will go to a DI on the ECU. 5v and sensor ground also go to the board. 

You'll also have to do some number crunching for the speed calibration, this'll also make gear detection available. The explanation for that is in the PCLink help file, "Speed Sources" in the "Chassis and Body" section. If there is an abs ring on your driveshafts, you'll have to count the number of teeth, you'll use that in the equation. You also need wheel diameter, not just the rim but the rim and tire.

Luckily, you're AWD with 4 driveshafts, I had to tear apart a whole wheel bearing assembly to get the front teeth count on my car lol. 

[Adamw]

The Evo doenst have individual wheelspeeds connected to the ECU.  You generally also only have 2 spare DI's on the Evo9 ecu so you may need to lose some other functionality to bring 4 wheel speeds in.  

Before you do that though, I would try just temporarily connecting just 1 wheel speed sensor to confirm the ABS and AYC/ACD is still happy.  Many ABS systems have complex fault detection with the ground isolated from the rest of the electronics so wont tolerate being connected to a device which references a common engine/chassis/sensor ground.

[k4nnon]

Thanks for the info guys. This is beginning to sound like more of a pain in the butt than needed. I may just ditch the idea rather than take on a big project. My interest was towards being able to play a log back and see where traction is lost. I might just simplify this and try to set up a front vs rear loss somehow?? If you have any info on this as well i may need some brain power. Im setting up for autox next season and i want to use the link as fully as possible for track data. I feel like some wheel speed info would be good for that. What if all 4 could be sent through a CAN system? Again might be too much work for what its worth. might just leave it alone haha. Thanks again.