164S Terminal Velocity Tested

[Paul Rollins <psroll@domain.elided>]

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From: "Pro Speeder" <roadkiller@domain.elided>

Pronto!

In a recent independant test conducted in a 1991 164S the speedometer
ind=
icated a speed of 155 mph while climbing a slight incline.

Shortly after the 155 mph indication was achieved the speedometer was
che=
cked with the aid of highway mile markers in three separate 10 mile runs
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with the cruise control set to 80 mph. Three separate tests were run to
o=
ffset any variance in speed due to any elevation changes of the roadway.
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The results of all three tests fell within a narrow range.

The speedometer test results indicated an average error at 80 mph of
5.01=
935% resulting in an indicated speed of 155 actually being 147.22001 mph
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if the indicated error is constant at all speeds.

I recall a recent thread on the terminal velocity of 164s but do not
reca=
ll the definitive results of that thread. I would like to know if the
abo=
ve test results fall above or below the "technical limitations" of the
ca=
rs top speed.

Please send all replies regarding this post to the Digest.

Ringraziamenti,
Professional Speeder
Somewhere in the North America >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

I think the only valid conclusion you can draw from your
speedometer-accuracy test at 80 mph is the error at 80 mph.
Extrapolating from there to 155 mph assumes linearity in the error
relationship. You need more data points to develop a more reliable
relationship between actual and indicated speeds. Even then, the only
way to be absolutely sure of the actual speed at 155 indicated mph is to
drive at 155 indicated and measure actual speed by some rigorous method.

Paul Rollins

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