Throttle %, brake pressure and ABS?

[Kroggers]

I am looking to include some more data channels to the Racelogic system in my racing car. I have been trying to get the answer by looking at the workshop manual, but could do with some help

I want to record throttle%, brake pressure and ideally also when the ABS activates.

The car is a 2001 Boxster s, so I have the e-throttle. Anyone know what wire at the pedal has the throttle position? I will assume it is a voltage range?

Is there anywhere I can collect brake pressure and ABS activation without having to include additional components to the factory system?

Any help is greatly appreciated...

[paulv]

Originally Posted by Kroggers

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The car is a 2001 Boxster s, so I have the e-throttle. Anyone know what wire at the pedal has the throttle position? I will assume it is a voltage range?

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The pedal has a pair of potentiometers that are used (this is a typical approach in case one of the potentiometers fails there's still a signal to the DME and the car can "limp" home). I'll tell you what the wiring is for my '07 MY and you can get some ideas from that:

The pedal value sensor has 6 wires in its harness.

First potentiometer -- leads 1 (GRN/BLK); 6 (VIO); 5 (GRN/BRN):
Lead #1 is the ground (provided by DME); Lead #6 is the "wiper" part of the potentiometer; Lead #5 is the "fixed resistance" part of the potentiometer.

Second potentiometer has the same setup: Lead #3 (GRN/GRY) is ground; Lead #4 (GRN/YEL) is the wiper; Lead #2 (RED/VIO) is the fixed resistance.

Sorry I can't help you with the other items. You really need to get a set of wiring diagrams for your car. It's worth buying an AllDataDIY subscription.

HTH

Regards,
paul...

[madmods]

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[Kroggers]

Originally Posted by paulv

The pedal has a pair of potentiometers that are used (this is a typical approach in case one of the potentiometers fails there's still a signal to the DME and the car can "limp" home). I'll tell you what the wiring is for my '07 MY and you can get some ideas from that:

The pedal value sensor has 6 wires in its harness.

First potentiometer -- leads 1 (GRN/BLK); 6 (VIO); 5 (GRN/BRN):
Lead #1 is the ground (provided by DME); Lead #6 is the "wiper" part of the potentiometer; Lead #5 is the "fixed resistance" part of the potentiometer.

Second potentiometer has the same setup: Lead #3 (GRN/GRY) is ground; Lead #4 (GRN/YEL) is the wiper; Lead #2 (RED/VIO) is the fixed resistance.

Sorry I can't help you with the other items. You really need to get a set of wiring diagrams for your car. It's worth buying an AllDataDIY subscription.

HTH

Regards,
paul...

Great stuff, thank you Paul. So I should be able to get the signal from either pin 4 or 6?

Originally Posted by madmods

I could be wrong but I believe the ABS trigger is computerized. You would need to access the raw data of the ECU for those figures. e.g. if the wheel speed is not equal the computer modulates the ABS system until the speed is equalized.

Easier to do with additional components imo. You could think of a linear potentiometer on the brake pedal and a magnetic hall sensor on the wheel. You'd be able to capture your 0~5v and aggregate those to your needs far faster than decoding the manufacturer ABS' computing thing

I was assuming there was a signal on a wire I could connect to which had a ABS on or off on it

[The Radium King]

wiring for your car here:

http://www.pelicanparts.com/techarticles/Boxster_Tech/11-ENGINE-911_Engine_Swap/Electrical_Diagrams/Carrera01A.jpg

and here:

http://www.pelicanparts.com/techarticles/Boxster_Tech/11-ENGINE-911_Engine_Swap/Electrical_Diagrams/Carrera01B.jpg

colours for the 7.2 tps look similar to the 7.8 quoted in the post above. had a quick look for abs signals to the dme but couldn't find. I do know that they talk to each other but uncertain how.

[paulv]

Originally Posted by Kroggers

Great stuff, thank you Paul. So I should be able to get the signal from either pin 4 or 6?

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You need to get the signal value from the wiper contact and the fixed resistor contact -- what ever those are.

Check out the wiring diagrams that The Radium King was helpful in pointing you to.

Regards,
paul...

[madmods]

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[The Radium King]

just went into my car with my pst tool and confirmed that the only actual values that the abs module provides are wheel speeds.

[Kroggers]

Thank you all for the great information and help.

Madmods, I am interested to record throttle % and brake pressure as a main thing so that I can see better how I drive after a race. The reason for recording when the ABS comes on (apart from the fact that I can feel it), is more for my own education. I have had the ABS do some strange things on me during a race, and I want to see what conditions create the issues and also in general how often the ABS actually does come on during a race - maybe I can just remove the system???

I think for now I will collect throttle % from the pedal and at the same time brake on/off from the brake light switch...

Thank you for the links Radium King

[madmods]

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[Kroggers]

Yes, and I am leaning towards removing the ABS in my racing car - more due to the fact that it keeps doing stupid things! But I wanted to record how and when the ABS is coming on so that I can try to get to a point where I feel happy to remove it...