homebrew spark-cut limiter prototype, working

This is the latest version of my homebrew Bee*R spark-cut limiter clone. It runs a PIC 16F88, power is regulated with a LM7805 with a low-pass filter and a bunch of big capacitors to filter noise. It uses the Crank Angle Sensor pulses to detect and calculate RPM. This vid was taken just after I found the solution to keeping noise off the RPM detection input line, thus today is the first time I was able to correctly read exact RPM without craploads of interference.

This prototype currently uses a power mosfet to pull the spark-transistor trigger line to ground, which is how the Bee*R unit works. This is going to change in subsequent designs because pulling the trigger line to ground cannot be good for the car's ECU. Future versions will use a solid state relay to disconnect the trigger line, and a pull-down resistor to pull the spark-transistor low while limiting.

The RPM limit is set to around 3100 RPM and the recovery distance is around 100RPM. First two examples are basically planting my foot nearly to the floor, and third one is me slowly building revs up, but when the tacho stops my foot keeps going down but the revs stay constant.
Ignore the very noisy lifters and the exhaust leak noise. They are not the focus of the video.

Read full discussion here: http://forum.r31skylineclub.com/index.php?topic=136241.60

Category:

Science & Technology

Tags:

• Bee*R
• Spark-cut
• limiter
• r31skylineclub
• r31
• revlimiter
• rev

[machinationu]

now you can build a engine brake (off the gas)