JasonC SBB

..and get better timing resolution due to more frequent updates?

Will it benefit from a 4-tooth wheel with evenly spaced teeth as opposed to the 4 unevenly spaced teeth on the 99/00?

Can it be made to work with the above?

TurboRoach

iTrader: (3)

You could use either as long as you have a reset pulse. Either from the CAS or a missing tooth. The install manual recommends using as many teeth as possible...

I think the uneven teeth might enable it to work without an external reset, similar to a missing tooth.

JasonC SBB

The uneven teeth on the crank won't do that. It repeats every 180* crank degrees. You can't tell from it which way the crank is pointed.

In contrast, a missing tooth on the crank pattern would repeat only every 360* crank degrees.

TurboRoach

iTrader: (3)

How are they unevenly spaced?

If only 1 tooth is at an odd spacing it would only repeat once per 360*. You would get short-even-even-long or something like that, right?

I'm asking because I'm still trying to figure out the different methods for generating crank signals.

Huh?

JasonC SBB

The teeth cadence is like this

1001000100100010010001

Get it? They are narrow pulses, 110* and 70* apart.

IOW they arrive at 10* and 80* BTDC of each cylinder. These tell you how far you are from each TDC, but you can't tell which of the four cylinders is coming.

A missing tooth OTOH would tell you which pair of cylinders is next.

TurboRoach

iTrader: (3)

Got it, I can see how that pattern would be ambiguous.