G-Tech Pro Competition, User Manual

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G-TECH / Pro Competition User Guide, Release 3.1
However, in the “real world” (i.e., at the track), your vehicle
has to contend with issues such as aero drag.
Suppose that two vehicles with identical engines, drivetrains,
and tires go to the same dyno. One vehicle has been modi-
fied to minimize aerodynamic drag. They both go to the dyno
in town and measure identically.
On the G-tech, the vehicle that is more aerodynamic will
measure a higher
net horsepower . This is because it loses less
power due to aerodynamic drag on the track as it is slicing
through the air.
The optimal driving technique for measuring horsepower and
torque is nothing like the technique for obtaining the best 1/4
mile results.
We will describe the technique here and then provide some
supporting information afterwards.
1. Stage the G-tech just as you would for a 1/4 mile run.
Wait for the “Launch when Ready” message.
2. At a moderate RPM value, start your vehicle briskly off
the line, enough to trigger the G-tech and start its clock.
Don’t launch as hard as you would for a quarter mile.
For example, if your vehicle redline is 6000 RPM, launch
at 1500 to 2000 RPM, for example.
3. Shift out of 1st gear before you are halfway to your
vehicle’s redline. So if your vehicle has a 6000 RPM red-
line, shift to 2nd before you reach 3000 RPM in first
gear. Be sure to let off the throttle between shifts, i.e.,
while the clutch is not fully engaged.
4. As soon as 2nd gear is fully engaged (which should be at
a low RPM, since you shifted out of 1st gear very early),
floor the accelerator. Keep the “pedal to the metal” until
your vehicle’s redline.
5. This allows you to cover a very wide RPM range in 2nd
gear at full throttle. Don’t worry about the fact that you
aren’t in the sweet spot of your power band when you
first shift into 2nd gear. That’s the point: we’re measur-
ing the power over the whole RPM range.
6. Once you reach your upper RPM value (e.g. redline) in
2nd gear, shift into 3rd gear and accelerate briefly
(maybe one second or so.) This does not have to be
full-throttle, since we are using 2nd gear for our horse-
power measurement.
7. At this point, you can press to stop the G-tech from
measuring, or just coast (foot off accelerator). The G-
tech will stop its clock.
8. Now you can view the “Horsepower and Torque vs
RPMs” graph for your run (p. 72).