Re: Climate Control channel 22

[Chris Newbold <cnewbold@transarc.com>]

Phil & Judy Rose wrote:

> BTW, the Bentley indicated that the channel 22 (speed) output was phased-in
> for later models in the '89-'91 series. Do all the later-than-'91 models
> have it?

The CC used in later model years has this, too. The system for
the 92- 100, A6, S?; the 93-95 90; and the 96- A4 are all pretty much
identical; I believe that it's channel 17 on these systems. It shows vehicle
speed in km/h.

> (1) Isn't it possible that CC-22 may inherently show the vehicle speed with
> greater accuracy than the speedo dial? If so, it might give useful

I've found this to be true on my 1993 90. Curious, I checked it against
one of those "Speed limit is XX, your speed is YY" radar signs; not
the most accurate, but another frame of reference...

(Actually, Phil, I think it was out on East River Road... :-)

I found the CC reading within 1MPH (after conversion) of the radar sign,
at about 60MPH. The speedo was about 3MPH higher at this point, which
doesn't seem all that unreasonable.

> (3) The digital CC-22 value might be used for a more-precise timing of
> acceleration runs (just a guess).

BTDT. A couple years ago, or so, when we had the Great 30-70MPH
acceleration timing "contest", I used the CC readout to do my runs rather
than the speedo. The only problem is that the sampling rate is a
little slow, perhaps 0.5 sec or something like that.

Oh, and you've got to remember to look up every once in a while and
not get too fixated on it :-)

-Chris
1993 90CS 67k miles