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Engine Specific Info and Questions => IDI Engine => Topic started by: TedV on May 06, 2008, 09:31:28 am
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All the local dyno's use an inductive pickup, similar to a gasser timing light pickup, to get the RPM reading for HP, torque vs RPM.
anyone have a trick for producing this? where to purchase? components to fabricate? stick a timing light on my current tach wire and see if I'm really lucky???
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Not finding anyone local I can borrow the adapter from, and at over $200 for one, there has to be a cheaper alternative.
use my tach pulse to trigger a gasser ignition module to fire a coil with a plug wire ? All parts I have laying around the garage.
Rube Goldberg is my hero. :lol: :lol:
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Sadly there's no easy answer here.
The inductive pickup on the dyno is expecting one pulse per every two revolutions... a 50 kV pulse.
Anything hooked to the W terminal on the tach is going to be 8 or 10 times too fast... if you can get the square wave from the alt looking enough like the signal from a hall-effect transducer to fire an ignition module.
You could do the math and re-calibrate... but I'm not sure if the average dyno would handle RPM readings of 40-50K ?? Dunno if your ignition module would fire that fast, either ??
I think you'd get there quicker using a super magnet glued to the crank pulley... read it with a hall-effect stolen from a distributor (which your ignition module is expecting to see anyway) and now you're only out by a factor of two... 10K RPM *should* be within range of the average dyno ?
In fact, tell the dyno it's an 8-cylinder and you're golden from a calibration perspective... I think ??