| |
| The
pack is close to fully charged, reading 384 volts. |
| |
| I
go out and immediately turn a 1:26. The track is dry and I have had
some time to think about how to drive it. |
| |
|
I run
12 timed laps (14 total) at 400 amps.
There
is some traffic, but I run 4 clean laps at 1:26.1 - 1:26.2.
Battery
temperatures go from 39.6 C to 52.0 C.
We
have used 23.293 kW-hrs.
|
| |
|
The
pack must be 45 degree Celsius before we can begin to charge. We
place a fan in the front airbox and blow air through the battery
boxes.
At
11:48 a.m., we put the car on charge.
|
| |
|
We
are using 824 watts-hrs per mile.
Therefore,
we will need 28.288 kW-hrs for the race,
plus power for a pace lap and a cool down lap, at 250 Watts-hrs
per mile.
All together, 29.298 kW-hrs.
|
| |
|
Fully
charged, the pack should be able to supply 35.150 kW-hrs at a 1C
rate of discharge.
This
means, if we ran the car at a constant 100 amps, we would be able
to use 100% of the 35.150 kW-hrs (see Puerkets
equation for more information).
|
| |
|
Looking
at Kokam's
Discharge Characteristics graph on the center of page 14,
it shows that at 4C (400 amps) we should be able to use around 87%
of 35.150 kW-hrs or 30.580 kW-hrs.
It
sounds like 400 amps will use almost all our power, but we should
be able to finish.
|
| |
| We
decide to turn the power up to 450 amps to get a Watts per mile figure
just to see if we can run a little more power. |
| |
|
Our
race engineer, James Lee and I discuss the car's handling.
|
| The
balance of the car has changed since our last race at West Palm Beach.
Now that we have brakes that work and improved tire grip, the car
is reacting differently. |
| |
|
The
higher g-forces are causing more weight transfer. The car is not
turning in well and is understeering mid-phase.
To
compensate, I am pitching the car sideways under braking and then
letting the car understeer around the corner.
|
| |
| This
is not optimal. |
| |
 |
| |
| We
decide to soften the front sway bar and the bump on the front shock
to try and increase front grip. |
| |
| |
|
 |
