July 11, 2004

At 6:45 Sunday morning, .

the voltage is 333 or what we guess is about 65%charge. By race time is has rising to 338 volts. Best guess 70% charge.

We arrange to start from pit lane. The rest of the cars will do a warm uplap and then take the green. Our plan is to come out behind them, do a slowlap to get a clear track and then do three hot laps.

Everything is working fine. The pack thunders by and we are waved out ontothe track. I am light on the throttle, keeping the amps below 150. I carry speed in the corners and the tires come in quickly. I get a little too enthusiastic through the chicane and use too much of the exit curb. It launches me straight, and to the outside of the tarmac. I catch the car. Definitely, not the fast line through this corner.

Just before turn 9, I look ahead to make sure I will have a clear run. Thru turn 10, I am hard on it.

The car accelerates and accelerates. It hits 5,600 rpm and keeps on going. It reaches 6,315 RPM. I lift a little early to get my braking right.

Regen current is 280 amps and voltage rises a little to 343 volts (3.89 per cell). This means around 156 lbf-ft of retardations by regen. I am trying to go to full brake with the regen and then modulate the friction brake pedal to give me the total slowing that I need. Looking at the data trace, I seem to have modulated both. Total time regenning 4.6 seconds. The car slows rapidly and the transition through turn-in is smooth.

I feed on the throttle and back to 600 amps quickly. 4,852 rpm before turn 3. Again full regen 240 amps taper off as I modulate for 2.7 seconds.

The turn 3 and 4 complex is a fairly long double apex corner. Half way through, the car is filling with white smoke. This is not good. I exit the corner and move off the racing line. The smoke clears a little. The turn 5 flag station does not really have a good place to pull off close enough for the workers to get an extinguisher on the car quickly. As I use regen to slow the car for turn 5, I get some more smoke. I keep going, torn between mashing the pedal to get there and my suspicion that this will only make the problem worst.

I pull off just beyond the corner worker station at turn 6. The smoke immediately dissipates. I wait with my hand ready on the built in fire extinguisher. No more smoke.

I signal OK to the corner workers and pull further off track. I sit and let the car cool. I wait until the all the racecars pass me twice, then drive quickly back to the pits. Everything works fine including regen. No more smoke appears but the smell remains. The batteries read 42 degree C, up from 26.6 C starting temp but still below the 60 degree C maximum recommended by Kokam.

First thing the crew checks is the tires for rub. That could give us white smoke when cornering but the smoke didn't smell right. We speak with Dr. Kim from Kokam and he assures us that if the batteries were off gassing, the smell would be very unpleasant. This is a relief, but we still need to find what was smoking.

What about the 'bundling' tape. We used lots of it as we assembled the car. It is a silver plastic tape that can be easily pulled off without leaving residue. This makes it incredibly convenient. What would happen to it if something beneath it got hot?

We plug in a soldering iron and put some tape on it. It melts producing a faint white smoke. It smells a lot like the smoke inside the car. The whole crew crowds around sniffing the soldering iron. I'm not sure this is going to help our reputation any.

The smoke seemed to have come from the behind the seat. If so, it will require removing the inverter before we can pull the battery cover and see. There is only a little time before the next race, so we decide not to push our luck. There will be other weekends.

Kw-hrs used: 3.48. warm up lap 2.25 miles at .225 = .506. Hot lap 2.25 used 2.97 = 1.32 kw-hr per mile.

And so ends the Electric Imp's soft debut.


join mail list animation
July 10, 2004
Sum Up


All content Copyright © 2016 ProEV Inc.,
USA phone (305) 610-6412
email: info@ProEV.com

Go to ProEV Home