Bob, Craig, and Listers:
The DMS dyno is an engine dyno, not a rear-wheel chassis dyno. The whole
thing is fairly compact; the frame is about 6 feet square, and the flywheel
housing, including bearings, clutch, etc. is about 3 x 3 x 3 feet. The last
iteration I saw was controlled by a 486 computer with an I/O controller
card.
Regardless of the absolute accuracy, the repeatability of this dyno should
be excellent, especially between runs on the same day. The other good thing
is that it tests the entire RPM band under load, so you will know if you
have a flat spot anywhere, without having to get steady-state readings at 50
RPM points.
Regards,
Theo
> -----Original Message-----
> From: Bob Palmer [SMTP:rpalmer@ames.ucsd.edu]
> Sent: Friday, March 31, 2000 11:58 AM
> To: Craig Wright
> Cc: 'Tiger News Group List'
> Subject: Re: "Stroker" Motor
>
> Craig,
>
> Thanks for pointing out this fact. Is their dyno made by Davenport Machine
>
> Service? My printout says it's a Dynojet Model 248C dynamometer. Your idea
>
> about how to calibrate it would work fine, as long as we have a NIST
> traceable weight and know the local gravitational field. Of course, the
> frictional effects you mention do affect the actual readings, so they
> would
> need to be accounted for somehow. Maybe what's needed is a NIST traceable
> power source, something along the lines of the calibrated 347 Jim
> suggested
> we use. (Just kidding of course.)
>
> Bob
>
>
>
> At 04:13 PM 3/29/00 -0800, Craig Wright wrote:
> >Bob,
> >
> >If you remember, that is the style of dyno used to test your car last
> November
> >at the Dyno Shop. I believe that one is rated at 1000 hp. I think that
> the
> >flywheel is not very large in diameter, but is long. This would keep the
> >stresses down and make it less likely to explode. An easy way to measure
> the
> >moment of inertia (polar, I think) is to apply a constant torque and
> measure
> >acceleration. Gravity can supply the torque by hanging a weight from a
> wire
> >wrapped around the flywheel. Keep the weight small and speeds low to
> reduce
> >aerodynamic effects and you should be able to get within 1%.
> >
> >Craig
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