I'm in the process of setting up an AIM Pista in my car. I have 3 of the inputs monitoring water temp, oil temp and pressure (ECU in the car is too old to communicate via RS232 or CAN). My original thought was to use 3 more for steering angle, throttle position and one for the brakes. I can tap the throt. position sensor on the car, will have to buy a pot. for the steering angle, but for the brakes I have some options.

I can either tap the brake light switch for a simple on/off record of the brake pedal, buy a pot. for brake pedal travel, or buy and even more expensive pressure sender to monitor the actual pressure in the system/master cylinder.

I guess my question is which would would be most useful to those with experience in this area? Tapping the switch would be super easy, but is an on/off record of what I'm doing with the brakes useful enough for the time being?

Get the brake pressure sensor.

I think it would be interesting to see the data on brake pedal travel versus pressure in the cylinder.

I think it would be interesting to see the data on brake pedal travel versus pressure in the cylinder.

Alex,

I think I remember you asking if you could get your hands on some data to play with in race studio 2 in another thread. If you are still interested, I have some data you could mess with if you want.

On/Off isn't all that useful in my experience. You need travel or pressure IMO.

On/Off isn't all that useful in my experience. You need travel or pressure IMO.

Good to know, thanks :)

I called up this company:

http://www.meas-spec.com/myMeas/sensors/sensorTransducers.asp

They will do "engineering samples" if you work for a company that that type of request is typical. (wink, wink, nudge, nudge)

The have sensors in the right pressure and voltage range. The only trick is that you will need to ask them for a calibration curve, develop one yourself or just use them as a relative measurement. There are not that expensive pressure gauges that fit into the bleed screw on the caliper for a home brew calibration.

I called up this company:

http://www.meas-spec.com/myMeas/sensors/sensorTransducers.asp

They will do "engineering samples" if you work for a company that that type of request is typical. (wink, wink, nudge, nudge)

The have sensors in the right pressure and voltage range. The only trick is that you will need to ask them for a calibration curve, develop one yourself or just use them as a relative measurement. There are not that expensive pressure gauges that fit into the bleed screw on the caliper for a home brew calibration.

Might be just what I am looking for, thanks! Calibration curves are easy enough to develope.

Why not use a linear pot and use it to record pedal travel?

I suggest the pressure sensor. It's the most useful thing, you can see how you modulate the pedal under braking. I can tell you that if the car has ABS, a hard application initially, with no release during the braking zone is the best way to get it done...
-Marc

I suggest using TWO pressure sensors; One on front and one on the rear. This will give you many options to analyze your braking, both from a performance/bias aspect, as well as your pedal effort.

Got one for sale.

http://forums.bimmerforums.com/forum/showthread.php?t=714520

Is the AIM GPS? I would think an on/off brake value, combined with a G-load graph would enable you to see when you're getting on and off the pedal, as well as how smooth your transitions are (based on G-forces).

The pedal pressure to me would seem to not do much good since it will change with your brake system's performance. Then again, if your brake system changes consistently, the pressure value will tell you how much it changes and you can adjust for it or at least plan for it.

Aem has a GPS module available, which is awesome from what I have seen so far, have not been lucky to try it out in person though (just the software).

Brake pressure is a great parameter to monitor.

Dragging up on an old thread -

Does anybody have pics of pressure sensor installs?
Do you use hard pipes or SS braided hose?

I would suggest using as little SS as possible. The more soft lines there are the more "play" there is in the system.

Is this an install on stock pedals or do you have tilton/wilwood type setup?

I would do a hard Tee off the factory lines. Cut it, flare it, splice it in.

Yeah, OEM system. I was thinking of doing a small manifold off the factory lines with flairs, bleeder and fittings.