Baseline Plots for Dynamic Dyno's 9-2X Aero Project Car

Baseline Plots:

November 14-19, 2005: As you can see in the table at the lower left, gas
mileage has suffered from too much fun tuning UTEC stage 1!
June 18, 2005: I ran a total of 4 runs today. The 9-2x currently has 1400 miles.

The first run was a 2nd gear run where I turned the AC on just after going
to full throttle to try and trick the ECU to leave the compressor on. The
trick worked for a good part of the Rev range and you can see that at
4000rpm you would lose about 20lbft of torque and 15hp if the
compressor did not disengage. By about 5500rpm the compressor
seems to have disengaged and the power loss disappears.
The second run was a 2nd gear run with the AC on, the third was a 2nd
gear run with the AC off and the fourth run was a run in 3rd gear. In third
gear the engine is not outrunning the turbo and you can see that peak
torque occurs significantly earlier since the turbo has more time to
spool. The graph at the left shows the 2nd through the 4th runs from
June 18th and also the two 2nd gear runs from June 12th. The 2nd gear
runs are fairly consistent with peak values varying by only a few
horsepower or lbft.
Fuel economy has fallen a bit since I'm no longer being careful to avoid
"rapid acceleration" as required during the break in period. The latest
tank shows 23.99 miles per gallon.

The first graph compares power and torque at the wheels for the three
runs WITHOUT altitude correction. The first graph shows that
significantly lower power is produced in first gear due to greater drive-
train losses and lower boost. This is one of the reasons why you should
perform all dyno runs in 2nd gear or higher. You can also see that the
AC compressor appears to rob power at most RPMs. Several runs will
be made in both conditions later to verify the AC effect.
The second graph compares power and torque at the wheels for the first
run with and without altitude correction. The second graph is further
evidence that SAE J1349 altitude correction should not be used in
evaluating the 9-2X Aero.
The third graph shows peak acceleration in second gear is

0.32G.

The fourth graph shows peak acceleration in first gear is 0.41G. You
accelerate faster in 1st gear than in 2nd due to gearing despite the lower
boost & higher losses in 1st gear.
The fifth graph shows peak acceleration in 3rd gear is 0.24G.

The sixth graph shows that the 2002 Acura RSX TypeS has greater
losses when performing a run with the AC on than the 9-2X. There are
claims that both vehicles disengage the AC compressor under full
throttle but the RSX seems to be less successful at it.
As a side note, I filled up the gas tank after the 3 runs and calculated the
gas mileage to be 24.53mpg average over the last 328.6miles. My
driving has consisted of approximately 70% highway driving. When I
purchased the vehicle in Phoenix and drove it down to El Paso, speeds
averaged 85mph ; I managed to get 26mpg by drafting (without
tailgating!) behind semis and large SUVs when practical.

June 8, 2005: The 9-2X is still technically within the break-in period at 850
miles and I am unwilling to make a run to redline quite yet. The purpose of this
first run was to evaluate the quality of the spark plug signal on a Subaru, uhh... I
mean Saab. The spark plug signal turned out to be amongst the cleanest I've
acquired and no adjustments to the default spark plug signal detection
parameters had to be made in Dynamic Dyno. An interesting effect with respect
to the J1349 elevation correction factor can be observed even with a run to just
5000 rpm. The peak horsepower and torque values are more than 30hp and
30lbft higher than expected with the elevation set to 3750 feet. The peak values
fall to the expected range when setting the elevation to 0 feet. Setting the
elevation to 0 feet effectively eliminates the altitude correction. This initial run
suggests the 9-2X’s turbo and related electronics are able to compensate
entirely for the lower density air at 3,750 feet.`

Key Vehicle Specifications:

Baseline Dyno Plots