Roebling Road Raceway 4/29/07

Session 2 Sunday SARCC Race 2:01 PM

 

I am fourth row, on the inside as we come around for the start. Battery temperature is 33 degrees C and the pack started at 391 volts. The green flag drops. The car ahead of me gets a good jump and I am right behind him. I am past the 6th place car and on the inside of the track of the 5th place car. He brakes late and stay outside.

I roll back on the power and do not feel the full surge. The fifth place car moves back in front of me and pulls away. I rightly suspect that I am on one motor again. I must have pressed the Regen pedal in the first corner and the current limiting software did not react fast enough to keep the voltage from spiking over the 400 volt hard limit on one motor.

I make my car as wide as possible and prepare to try a fast reboot. Entering turn 6, the six place car bulls back by. I stay outside as a line of cars stream by the inside. I flick the switch to neutral, cycle both switches and press the start button. Flick the car back into gear. Full throttle. Still one motor.

I am driving like someone on a cell phone. Weaving while trying to look down and press buttons. 15 cars have gone by. This is too dangerous for everybody, so I pull off the track and behind a corner worker station.

 
cycle switches
 

Neutral, cycle the switches, press the start button. Only one motor comes on. Cycle the off motor switch. Press the start button. The other contactor closes. I head back out towards the track.

As I get up to speed, the lead car laps me. I soon find myself back in sixth place battling with the leaders but a lap down. I turn a 1:26.075 on my third lap. .7 faster then yesterday's race.
 
Using the whole road video (~1.12MB .wmv file)
 

Coming into Turn 4 on my 7th lap, I smell a battery let go. I then smell smoke and think about what corner station I can get to for fire extinguishers. Exiting turn 5, I continue off the road and up the hill, waving my hands at the corner marshals. As the car comes to a stop, I activate the in-car halon extinguisher. Next, I pop my belts, climb from the car and turn off the master switch.

The marshal has arrived with a 'ABC' type extinguisher. There is still a little smoke from underneath the metal panels behind the driver's seat. I take the extinguisher and squirt some under the edges.

I shut down the computers and cameras while keeping an eye on the smoke. It seems to be lessoning. The track fire truck appears (gas race cars catch on fire regularly) and they help me remove the Lexan that separates the driver compartment from the back of the car. I nix using a big metal crowbar on the top of the battery pack. We just bend up the corner a little by hand and pull out some smoldering plastic. The race has ended, so they tow me back to the pits. This turns out to be unnecessary as the car despite two bad batteries, can still run on it's own.

When we get the racecar back to the shop and pull the battery covers, we find that a wooden board that supports the outside of the battery pack has progressively bowed out under the high G loads of the left hand turns.

 
 
Before...notice how straight rear board is
 
wood support before... arrow marks unsupported gap
 
after...bowed wood support looking at batteries from above
 
Eventually the farther outside cell (#001) developed too much of a bend and vented. When it vented, the Coroplast plastic spacers began to burn slowly. This fire also charred a wood support. The heat damaged cell #002 as well. The cells themselves did not burn.
 
fire zone, coroplast removed, charged wood support
 
We will have to redesign the cell supports to make them stronger and out of a more flame resistant material. Flame resistant Coroplast is desirable but we are still unable to find a supplier.
 
The 'ABC' type extinguisher is a nightmare to clean up. In a high humidity environment, it tends to cake and stick to everything. We are warned that if left on, it will attract moisture and cause corrosion.
 


content2

join mail list animation
Dec 31, 2006 Race 2 Moroso
Battery Beach, Jan 2007

DISCLAIMER

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

Go to ProEV Home