Too bad you didn't have the circumstances I had about 28 years ago.

I was rallying a 1973 Renault R12 (1300cc) up around Peterborough
Ontario.
NAVEX rally- unprepared car - perscribed average speed 43MPH IIRC,
through loose sand on forest roads. (The Renault was the lowest
powered car in the series but managed a 4-3-2 finish for the 3 years
we campaigned it)
I came sliding into the checkpoint, timed to the second, with no
penalties after something like 40 miles since the last checkpoint.
About a minute later, just before I was ready to pull out for the next
stage, a Police cruiser pulled up behind me and the officer jumped out
madder than a wet hen. He claimed he was going to charge me for 85MPH
in a 50 zone.
I looked at him and just about cracked up. He asked what was so funny.
I said the car wouldn't do 85 wide open downhill with a tail wind, and
I could prove to him EXACTLY what my average speed had been for the
last 40 (or whatever) miles. I told him I had averaged 43 MPH, and
would admit to possibly having hit 50-55 MPH once or twice for a very
short stretch, but more importantly to cornering at close to 40MPH. If
he was doing 85 trying to CATCH up to me, and cornering with his LTD
at about 2MPH, I could see that, but no way was he doing that to KEEP
up with me. I referred him to the check-point marshall and told him
We'd see him in court if he wanted to lay the charge.

At the end of the rally the checkpoint crews were having a good laugh.
The poor copper had NO IDEA where he was - whether he was even still
in Ontario or not. They had to give him detailed directions (they gave
him the rally instructions) to get him back to the highway, where he
was WELL out of his local jurisdiction.

On Dec 3, 8:34 pm, lolajo...@webtv.net wrote:

High-school maths...

gravitational potential energy = mass.g.height

So on a theta-degree grade at velocity v...

power (P) = m.g.v.sin(theta)

for 1250kg car, 77mph (34.4m/s), 5 degree grade (~1:11), g ~ 10m/s^2,
you'll need

P = 1250 x 10 x 34.4 x sin(5)
  ~ 37kW

Not sure what revs you do at 77mph, maybe 3500rpm?

What power does the 2.5 generate at those revs.. approx 70kW?  Take
about 20% off that for drivetrain losses, so say 56kW atw.

Subtract the amount of power required to push the car through the air,
no idea what that is. From this site, http://phors.locost7.info/phors06.htm,
we can guess at about 15kW.

So our theoretical car (with 41kW excess at the wheels at 77mph),
could probably do up a 5.5degree grade (1:10.5) at 77mph. (asin(41e3/
(1250 x 10 x 34.4) ~ 5.5deg)

Adjust for more sane numbers as you acquire them.

Did you ask the officer to see the reading on the device used to
measure your speed and upon which that officer made the decision that
you were speeding?  If so, did he refuse to show you the reading?  Was
the device already reset?  Was the device in his car or was he a 2nd
unit that merely got radioed the speed?  Let the cop understand that
you will demand the evidence in court, but only mention that and never
afterward indicate whether or not you will show up in court.  You'd be
surprised at how many times the officer never gets informed or elects
not to show up.

If you believe that you cannot attain the speed that the officer
claims (and you are willing to risk another ticket), take a friend
along who is willing to show up in court and testify as to what
maximum speed you able to attain on that section of road.  However,
did you ever ask the cop as to just exactly WHERE he made his
measurement?  Maybe you weren't even on the hill when he snapped the
trigger.  The ticket should stipulate the location.  Is it on the
hill?  Is it at a reasonable distance up the hill so that any higher
speed before the hill would have been trimmed off by that point noted
on the ticket?  Does the ticket actually have a specific location (as
a distance marker or intersection) or does it just list the road you
were on?

However, if the speed you do attain on tape is over the speed limit (even by
a few miles an hour), be prepared to accept another ticket based on the
video evidence you are going to submit.

Jon

Might help.  Remember the statement the cop made (they write down everything
you said), and do some research on that particular gun.  None of them are
perfect, and the manufacturers explain that in their literature.  What you
need to do is put some doubt into the officer's statement.  Right now it's
you against a number on a radar gun.  Generally that's not a very strong
case unless you said something to the cop to nail it down.  "I don't know
how fast I was going," is not a good thing to say.  If you didn't know it
gives a lot of credence to the officer's statement.

Good luck.