Software Newsletter #16 - July 11, 2001
1. The Truth About Humidity and ET Prediction
2. Lebanon Valley - A
3. New! High Temp Gun-Style Infrared Thermometer
4. FREE Software Download
5. REAL World Technical Support
6. Most Accurate
-- The Truth About Humidity
and ET Prediction --
Frequently, I get asked about the effects of humidity
on ET Prediction. Many racers try to develop their own 'formulas' for predicting
ET using a spreadsheet program. It just can't be done. The scientific formulas
that we use are much too complex for that. Humidity is one of the hardest of variables
to work with because it's effect on ET changes dramatically with temperature.
Some racers will say that humidity is the ONLY variable that effects their car.
Or, humidity effects my car differently. This is not true! However, if you are
not measuring the temperature, barometric pressure, and humidity accurately, or
using a program that doesn't calculate the effects of humidity properly, your
results may lead you to believe such myths.
The secret to ET Prediction
is calculating how much oxygen is in the air presently, RELATIVE to a previous
time. And then finding the loss or gain of horsepower due to the specific change
in available oxygen. Engine performance then, is only effected DIRECTLY by the
amount of oxygen molecules in a given cubic foot of air. Nothing else.
The variables, Temperature, Barometric Pressure, and Humidity are responsible
for the change in available oxygen. Barometric Pressure compresses the air and
allows more room for oxygen molecules. So, the higher the Barometric Pressure,
the more horsepower your engine will produce. Higher temperatures expand the air
molecules, and therefore decrease the room for oxygen. So, the higher the Temperature,
the less horsepower your engine will produce. Humidity is just water vapor. The
presence of water vapor takes up room and therefore, displaces oxygen molecules.
So, the higher the Humidity, the less horsepower your engine will produce.
Temperature is the biggest factor in predicting performance, not humidity.
However, the higher the temperature, the bigger effect humidity has on performance.
If you are not measuring the temperature accurately, then the effect of humidity
can not be calculated accurately. And, at higher temperatures this becomes very
dramatic. For example, at 70 degrees, the addition of 82 per cent humidity could
slow your ET by .073 seconds. At 78 degrees, the same amount of humidity could
slow your ET by .100 seconds. Almost three (3) more hundredths due to the humidity
alone. About .026 more due to the change in temperature alone. So, if you read
your temperature gauge wrong, or your gauge was inaccurate, under high humidity
conditions, your Predicted ET could easily be wrong by .060 of a second or more.
Garbage in, garbage out.
Valley - A Refreshing Experience --
do I love Lebanon Valley. They have this race planned at just the right time of
year. Just when, you are fed up and ready to quit racing, you go to Lebanon Valley,
the pause that refreshes! I wish every race track could follow suit.
We arrived late Thursday afternoon and because there was a test and tune, most
of the parking was already filled up. As usual, many spots were saved, but I noticed
a few empty ones. When we were told to go out to 'the pasture', I mentioned that
I saw a few spots close to the staging lanes that I could easily fit into. Immediately,
I was given one of these better spots. Cool!
After getting parked, we
walked up to the head of the staging lanes and noticed that the track was being
scraped and prepared for Friday's time session. The track was in excellent condition,
for the very first time run. Our DataMaster data recorder showed that traction
was better here than at any track I have been to this year. And, the track was
kept in good condition over the entire event.
Friday night we were treated
to Alcohol qualifying, Jet Cars, Top 8 races, and a wonderful fireworks display.
Saturday night we were treated to a free barbecue hosted annually by Chuck Rothermel
and friends. The Auto Start system worked perfectly, with the delay for Super
Comp being set at the proper two second interval for each round of competition.
Super Comp was third out each morning and the schedule was followed almost to
perfection, even with some bad weather conditions. No one was skipped over. Imagine,
we were actually racing in the morning again!
We had lights of .410,
.414, .403, .400, and .416 before going red. I always go red at Lebanon Valley,
at some point, so it was expected. No big deal. First round we went .400 with
an 8.8993, just 7 ten thousandths from a perfect run. I have a perfect run with
my old car, but it was done during time runs, so I guess it doesn't count. So,
this was a memorable race for me..
Now, don't get the impression that
this is unusual treatment. I went to Lebanon Valley for the first time in 1995.
I remember arriving at about 5:30 AM. Instead of having to wait, we were parked
that early in the morning! Then, a truck pulled up behind us. It was the owner
of the race track and he gave us coffee and donuts! He also gave me a can of nonalcoholic
beer and said that if we win the race, to use it to celebrate. We did win the
race! And, I still have that unopened can of beer. Every year since then, it has
gotten nothing but better. It is always worth the trip.
-- New High Temp 'Gun-Style' Digital Infrared Thermometer --
offer another Digital Infrared Thermometer with Laser Sighting, Part # IRT4. The
new Gun Style unit has a temperature range of 0 to 788 degrees F, has a backlight,
an 8:1 Optical Resolution, and an Auto-Off feature. The introductory price is
just $99.95! That is about what you would pay for a unit WITHOUT laser sighting
and with a lower temperature range. Comparable prices for a unit with these specifications
is about fifty or sixty dollars more.
-- FREE Software Download --
The DOS version of our DataMaster Analyzer software, Version 2.0, is available
to you as a FREE download on our web site. (The Windows version is too big to
download because of all the associated Windows Dll's and other MicroSoft files
that have to be installed.) You don't need a data recorder to test the software
and see exactly what a DataMaster Sportsman Computer does better than any other
data logger system in the world! Yes, better than the most expensive data logger
in the world. Only, ours is not expensive. If you have any older version of this
software, download this as a FREE update.
-- REAL World Technical
With Family Software, you'll get better technical support
than anywhere on the planet. Why? Because, we design and/or use all of the products
that we sell. All of my 30+ years of racing experience and knowledge is available
to you and our other customers. Try to find that kind of information at any one
of our competitors. You won't be able to, I guarantee it! Family Software cares
about the racer and his/her success as a racer. The other companies just want
-- Secure Ordering --
You can safely order directly from
our web site. All of your information is handled on our Secure Server. We have
registered with the Public Eye for safe, secure ordering.
you have questions or topics that you would like to see covered in this newsletter,
Family Software - Drag Racing Computers and Software
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