Measuring blower speed
basically, to allow you to determine the amount, if any, slip you are having in your blower drive system.
It can be using you ecu, or a simple in-car guage. Doesnt matter.
If you have...how did you do it ??
I use the front ABS sensor to work my speedo now, just had to play with the numbers some to get it accurate.
There are several ways to do it, I am using an infrared sensor mounted to the blower and aligned to see light reflected from a stripe painted on the blower pulley.
Here is a link to the sensor:http://rocky.digikey.com/scripts/Pro...V=46&M=QRB1134
Basically you're creating a tach signal to be read by your logger.
Another way is to use a hall effect or VR pickup with a magnet or stud mounted to the pulley. The hall effect sensor is not reliant on rpm to create voltage, nor would it be affected by dirt or dust on the pulley as the optical sensor will be.
For 1 revolution, it expects a minimum of 4 teeth, although this shouldnt be a big deal. If I used one tooth, "speed" would just be 1/4 of what I see on the computer.
If I baseline at 1000 engine rpm I could get an easy reference to see if blower speed rises in a linear fashion with engine speed.


