ET Prediction Computers:
ET Predictor II Computer
- Sharp PC-1270
# ET-1000 ET Predictor II Computer (V6.06)
Sale Price: $250.00
are no longer made by Sharp)
The ET Predictor
II computer, will enable you to properly manage air/fuel ratios
for the current air density, track vehicle performance or modifications,
and accurately predict elapsed time and throttle stop settings according
to varying weather conditions. Included are programs to calculate
Air Density, Horsepower Correction, Density Altitude, Vapor Pressure,
Water Grains, Engine Displacement, Compression Ratios, STP Corrected
Elapsed Time, Run Completion, Corrected HP from MPH, HP Corrected
Vehicle Weight, Throttle Stop Factor, and our exclusive Run Segment
Analysis program. The next best thing to having an on-board
computer. Comes with complete instructions and ET prediction hints
and tips. Nothing is more accurate for ET Prediction!
enter the air conditions from your weather station or weather gauges
into the program. We have weather instruments and weather stations
available here on the website.
For Gasoline and Methanol Fuel
Drag racing programs calculate:
ET Prediction (60, 330, 660, 1000, and 1320 foot)
Throttle Stop Prediction
Air Density Index
Horsepower Correction Factor
Dew Point Temperature
Water Grains Per Pound
Corrected Elapsed Time
Run Segment Analysis program, the next best thing to having an on-board
Predicted 330' ET
Predicted 660' ET
Predicted 1000' ET
Predicted 1320' ET
Inches HG to Altitude
HP from MPH
The ET Predictor software is the most accurate ET Prediction and
Weather Station software available because it uses Horsepower
Correction and does not predict from an average of stored runs.
The ET Predictor provides a Horsepower Correction Factor (HCF) and
Air Density Index (ADI) using a standard of 0 Elevation, 29.92 In
Hg Barometric Pressure, 60 degrees F Temperature, and 0 percent
Relative Humidity. Under these conditions, the HCF equals 1.0000
and the ADI will equal 100.0 percent. The HCF and ADI compensate
for pressure, temperature, and relative humidity. Conditions that
improve the HCF and ADI are cold air, high air pressure, and low
program uses the Elevation, Barometric Pressure, Temperature, and
Humidity, to calculate the current Horsepower Correction Factor
(Current HCF), Air Density Index (ADI), and Density Altitude (DA),
Dew Point, and Vapor Pressure. The formulas used in this program
are the same ones used in our ET Predictor II hand-held computers,
ET Predictor software, and RaceLog Pro software.
Elevation - Range: -3,000 to +26,000 Feet - Elevation is
only used if you are using an altimeter or a corrected barometer.
If you're using an uncorrected barometer reading absolute pressure,
always enter 0 for the elevation. If you have an altimeter, calibrate
it to 29.92 In Hg and enter the reported altitude as the elevation.
If you are using an analog barometer and your altitude requires
that you use a corrected barometer, then you should always enter
the number of feet equal to the amount of correction when you calibrated
the barometer. Digital barometers and altimeters measure absolute
pressure, without any need for correction, so their use is preferred.
Barometer - Range: 12 to 35 Inches Hg - If you're using a
barometer to obtain the air pressure, enter the barometric pressure
from the gauge. When using an altimeter, always enter 29.92 for
the barometric pressure.
Temp F - Range: 10 to 130 degrees F - Enter the temperature
from a digital thermometer or other temperature gauge. From round
to round, temperature changes are apt to affect performance more
than any other variable. RH% - Range: 0 to 100 Per Cent - You can
use a digital hygrometer to find the relative humidity. At low temperature,
relative humidity has the least effect on performance. However,
at high temperatures, the effect is much greater. For example, 50%
RH at 60 F will result in a .01 loss in power, while at 90 F the
addition of 50% RH equals about a .03 loss in power. Changes in
temperature are also more critical under high humidity.
following is more information on the resulting calculations:
Current HCF (Current HP Correction Factor) - The Horsepower
Correction Factor is computed using the current weather conditions
that you enter. In other words, the HCF equals the current elevation,
barometer, temperature, and humidity. When the HCF is higher, less
horsepower is produced, and the car will run slower. So, the lower
the HCF is, the faster the car will run. You can use the HCF to
determine the variance in horsepower or torque that is being produced
under different weather conditions. For example, if your engine
produces 400 horsepower with an HCF of 1.012, it will produce 404.80
horsepower at sea level conditions (STP) or 1.0000 (400 x 1.012=404.80).
Vapor Pressure - Vapor Pressure is the exact portion of barometric
pressure that is present due to Relative Humidity, or moisture,
in the air. Vapor Pressure is used in calculating the horsepower
Air Density (Air Density Index) - The Air Density Index (ADI)
is the computed ratio of the current density to that of STP with
STP having an index of 100 percent. This factor is used to determine
the correct jetting or pill size required under varying weather
conditions. The higher the ADI, the more air there is available
for combustion. Therefore, more fuel must be burned to maintain
the correct air/fuel ratio. When using gasoline, a four (4) percent
change in the ADI will usually necessitate a change in jet area
in order to maintain the same level of performance. Holley jet sizes
are about 4 percent apart in flow area. If the ADI goes up four
(4) percent, for example 100.0 to 104.0, increase all jet sizes
by one number. And, if the ADI goes down four (4) percent, for example
100.0 to 96.0, decrease all jet sizes by one number.
Density Alt (Density Altitude) - Density Altitude (DA) is
the current air density expressed in feet of elevation. DA is also
known as the corrected or relative altitude. DA is not scientific
and is very inaccurate. Therefore we do not use this factor in ET
Prediction. We only report this value for information purposes only.
Dew Point - Dew Point is the calculated temperature at which
condensation (moisture) occurs based on the entered air conditions.
Dew Point will tell the racer when the traction on the race track
will worsen due to condensation. When the actual measured air temperature
matches the Dew Point temperature, the race track will be wet.
Unsure about whose weather computer to buy?
To find out the cold hard facts about weather computers, read our
newsletter on this subject by clicking here.
We can repair all Sharp PC-1270 computers.
Also we can reprogram most Sharp PC-1270's and all Sharp EL-5500
III calculators to ET Predictor II specs for a fee of $125.00. This
includes all of these outdated (and inaccurate) units from:
your PC-1270 can be reprogrammed depends on what removable program
card it has. There are Sharp RAM cards, P*ROM Eprom cards, and Pygmy
of these Sharp RAM Cards can be reprogrammed:
RAM CARD 8 - Part # CE-212M
RAM CARD 16 - Part # CE-2H16M
RAM CARD 32 - Part # CE-2H-32M
RAM CARD 64 - Part # CE-2H64M
of the (gray) P*ROM brand cards can be reprogrammed but we must test
them in our machine to find out whether they are protected or not.
of the (black) Pygmy brand Eprom cards can be reprogrammed.
We can also reprogram all SHARP EL-5500 III computers to ET Predictor
II 6.06 specs. Call us!!