<all> home dyno kit??

[Roger Heflin]

On Thu, 28 Jan 1999, Mike wrote:

> >
> >> At 08:24 AM 1/28/99 -0500, Dan Llewellyn2 wrote:
> >
> >> >level ground.  At least were I live, level stretches of road where
> >> >you can get up to speed are rare.  If they incorporated the data
> >> >from a G-field measuring device, like an Analog Digital ADXL05,
> >> >you could calculate horsepower even if the road was not level.
> >
> >Yes, but you still need the speed input since the accelerometer
> >cannot tell the difference between acceleration and gravity...
> >As far as the horsepower calculation is concerned, you would
> >use the acceleration from the accelerometer and the speed from
> >another sensor...  The calculation (being mass * velocity * acceleration)
> >doesn't care whether the acceleration is due to gravity (going
> >uphill) or increase in speed.
> >
> 
> After reading some of the "audio" ideas recently, I thought about a slightly
> different way to do performance calculating, using just the primary ignition
> coil signal and the statistics of the car in question.
> 
> Why not hook (say) an HC11 to the coil primary and time period between
> edges. If the car is placed in, say, second gear and floored from 1000 to
> 7500RPM (my PGT fuel cut), one could use the ignition signal as both an RPM
> reference and also as a "delta-RPM" signal to determine how fast the engine
> is accelerating. On my PGTs V6, there's 3 pulses per revolution of the
> crank...is this enough I wonder? Time to pull out the notebook and start
> calculating.
>

That is mostly what the home dyno kit does.   You collect the
information off of a spark plug, and then use that to calculate
acceleartion based on the rpm changes.  The program is setup to record
the data as a audio signal and then later process that audio signal on
a computer to get the info out.

The person who did the home dyno kit is on the f-body list, and did
communicate with him some while he was first building the device.
 

			Roger