Revs gauge?

[bungbung]

I think the automotive tachs use a pickup on a spark plug lead. Selecting the right number of cylinders will allow the tach to calculate the correct reading.
If they did use a crank pickup the number of cylinders would be irrelevant

Almost. The pick up is on the LT side of the coil, so for a 6 cyl there will be 6 pulses every two revolutions. If the pickup was on the plug lead the reading would be 1 pulse per two revolutions.

Gets complicated on a wasted spark set up. The digital tach in my link allows the choice of two stroke/four stroke and 1, 2, 3 or 4 cylinders.

[Ivan]

well...your auto electrician mate is full of crap...and if he really is a auto electrcian...he would have told you to wire 2 resitors of equal value in series [basic basic too do]..on the input line and that would halve the signal.....


Now back why it works...crank sensor sends a signal every reveloution...no matter what configuration engine it is...it will still read the same!!!!!!

Now give me your auto electrician mates phone numbe...and I'll ring him up and explain this simple theory to him...and I promise I'll talk really slow so he gets it!!!

Damn this website always gets into this people going off at a simple question.

I think when he has the Quals and certs and has been involved in making a electric car I think he knows what he is on about.

The Wires that run on a auto tach dont run off the crank sensor they run of the Negative side of the coil.

[cowpoos]

Damn this website always gets into this people going off at a simple question.

I think when he has the Quals and certs and has been involved in making a electric car I think he knows what he is on about.

The Wires that run on a auto tach dont run off the crank sensor they run of the Negative side of the coil.

Well he's still is a dumb shit..and I still back my offer to call and explain to him!!

if its run off the coil...its still not a problem...crank turns twice every time the spark fires per cylinder.