March 26, 2005

Moroso Saturday

Session 1 (A + B)

We are waiting in line at 7:00 am when the track opens.

The pack voltage is around 322 volts or 3.66 volts per cell. The car is on charge by 7:40 a.m.

I go to find the chief steward and request permission to skip qualifying and start at the back of the field. The chief steward agrees so we have all day to charge.

Shawn Waggoner and Matt Graham arrive. They were a big help last race and pitch in today as well.

Shawn Waggoner (L) and Matt Graham (R)


After about 5 and a half hours of charging at 7.5 amps (40 amp-hrs), cell # 9 reaches 4.184 volts. Cell #9 has peaked about .16 volts before any other battery. Rather than undercharge the rest of the pack, we attach resistors and run our modified charge software which discharges the highest voltage cell while the rest of the cells charge.

It is getting close to our scheduled time to race but 'on and off' rain and a number of cars sliding off-track has slowed everything down.

The Race stewards announce their decision to shorten the remaining races to 10 laps. We cheer!

We debate upping the power but decide a race finish is more important than more speed.

Electric Imp on charge at Moroso

We continue charging for about 2 more hours, adding something less than 15 amp-hrs as we taper down the charge rate.

The pack is at 362 volts. 4.11 volts per cell.

This is a good charge. We are ready to race.

We grid at the back of the pack. There are 33 cars ahead of us.

I hope to conserve power on the pace lap but that is not to be. The cars ahead leave the false grid slowly and then have to race around the track to try and close up on the front cars before the green flag.

We are strung out between turns 9 and 10 when the green flag drops. The Mosler in front of me powers away.

I use only mechanical brake until the chicane. Cell #9 which is having a problem goes to 4.201 volts, otherwise 4.171 is the highest voltage we see. I don't want to over voltage the battery in their high state of charge.

Out of turn 6, I get a good run on the car ahead. He has more motor and almost makes it up on the straight but I put my nose in firmly and take the position.

I have a good gap at the start of the front straight but he has more straight line speed. I cover the inside and go through the corner.

The third lap is my fastest at 2:02.156 but I can see the car behind me regaining lost ground. Lap 4, he takes back the position. Motoring by on the straight.

I never see the checker as the lead car passes me right after the flag stand. We should finish our lap but the officials wave us in. This means one less lap to do, so we do not complain.

Of the 5 cars in our class, only one other has made it to the finish. We have taken second place!

75 plus years of development and they still haven't got those ICE's working right<G>.

I get a maximum of 240 lbf-ft in the chicane but mostly I seem to be running about 170 lbf-ft of torque.
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Peak Horsepower is about 90.
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Brake (actually regen) Horsepower is 130.
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Ending voltage is 322 or 3.66 volts per cell.

According to SIADIS, we have used 13.894 kw-hrs so we should have about 39% of capacity left.

According to our voltage study we have about 30% left.

Without active battery management, we have damaged a cell. Cell #9 dropped to below 2.8 volts around lap 5. By the end of the race it is sitting at 1.5 volts.

The car is harder to drive at 200 amps. There is not enough power to use the throttle to correct the car. And being passed is not something any driver likes.

Finishing the race is a milestone though! Our steady pace nets us a second place in class as all but one SPU car drops out.

When we start charging cell #9 is the lowest. An hour later, it is midpack.

 



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