MicroSquirt.com read only forum (Jan.15,2018)

Hello,

First post here
I have a microsquirt i am putting on my brothers single cylinder 4 stroke speedway sprint for ignition only control
https://youtu.be/t82TM3-lZ4I he is the red #35
I designed a 24-1 hall wheel in autocad and had it laser cut just small enough to fit in the existing timing compartment and i went with 24 teeth so that the teeth weren't too small as we see 11000+rpm when the track gets fast, The size of the teeth is comparable to those on the 6" wheel sold by diy
i have all the stuff ready to go, i actually have the ignition rigged up to my lathe right now to spin it and mess around (not all that necessary)

ok ill get to the questions......

1 Should the hall sensor be connected to vr1 + or - ?
I have the hall sensor output wired to vr1- as per the manual, i have been told by scott at diy not to hook it to -, I have been told by phill at diy to hook it to -, I have been told by matt at diy that it does not matter
I have a hard time believing that one way is not better than the other and we will be turning 11,000rpm putting the wheel and trigger to the test

2 Is it better to use 5v or 12 v with the threaded sensor diy autotune sells?

3 I have heard that a map sensor can be used instead of a cam sensor
would this work in my 11000rpm application?
hopefully this wont be hard to follow

4 the manual states that pin 18 is a sensor ground but that it is not installed, i have added a wire here it appears to be a ground, is it okay to use this?

5 On my 24-1 wheel, I entered a tooth 1 angle of 90* i set the advance to 0 fixed timing for verification on my lathe, spinning at 1300rpm it triggers on tooth 5 instead of tooh 7. what could be the problem here? I dont like/trust this.....

6 in the ignition setup, we have these options
single coil
wasted spark
wasted cop
coil on plug

which one do I use?
Its technically all of these things lol!

hopefully i have not rambled too much and muddied up my questions

Thanks,
Aaron Englert

With VR sensors, it does matter. But most Hall effect and optical sensors are equally stable on both edges, and you can invert the signal in software.

Generally, 12 volts will give a stronger signal on the sensor.

The MS2/Extra code (covered at MSExtra.com) allows using a MAP sensor instead of a cam sensor. It will sync up at low RPM and then stops checking for sync until the engine loses sync with the crank, so it doesn't need to "make it work" at 11,000 RPM - it uses the results from low RPM and will remember what engine phase it has from there. This mode requires setting the spark to "Wasted-COP".

Some of the harnesses have the sensor ground installed at pin 18 and some do not. It was a running change.

You may need to adjust the tooth #1 angle.