The Adventures of Bryce and Jessica

The REAL $2009 Challenge

October 13th, 2009 Posted in Car Stuff, Fiero

Well, the car has been dropped off at the transporter in Orlando and we got back home via airplane late last night.  We had some very, very bad luck with the car when we fired things up on Thursday morning.  The inverter and contactors were having some weird issues when I first fired the EV system up, so I started poking around with the multimeter and checking the codes on the computer.  After some poking around I found out that two of my four contactors had welded shut, which allowed battery voltage to the inverter at all times, not a good thing.  I also found that the inverter had some internal issues, which I suspected was related but couldn’t pinpoint it.  After pulling the inverter out of the car, I found some bad, bad news…one of the cards inside of it was smoked.  This made me a very unhappy camper.  Here’s what I was dealing with:

 

(Photo courtesy of Tom Heath, IIRC, modeling courtesy of Jessica)

I made a call to Al, who was planning on coming down in a plane in a matter of hours, and explained the situation.  He jumped into action and drove to his house, grabbed his inverter and some contactors, boxed it up, and just BARELY made it to the plane in time, so we had a spare on the way.  In further poking around, I found one string of batteries was low, about 25 volts lower than the other string.  I came up with a theory (which later proved out true) that the contactors welded shut when I turned the system on because the healthy batteries were trying to charge the dead batteries, which caused a huge current flow long enough to weld the contactors.  When I turned the system off, the contactors couldn’t break like they’re supposed to, so full pack voltage was still going to the inverter.  The card that burned up is a set of resistors that bleeds the voltage off the capacitors inside the inverter (for safety) and with full battery voltage going to the inverter, the resistors overheated and burned up (probably taking the transistors with them).

So, while still waiting on Al to arrive, I started charging the dead batteries to see if they would hold a charge.  I charged the handful of dead ones (all from the same Prius pack, which must not have been very healthy when I got it) but they wouldn’t hold a charge, they’d lose their charge very fast.  With about ten of the 42 modules in that string unhealthy, that meant one of my two strings of batteries were now useless (without replacement batteries).  Dammit!  Fortunately I still had one healthy string without any bad modules, so that was good.  I suspect that leaving the car locked up, windows up, in the heat, without any usage (no battery charging) caused the unhealthy cells to go dead.  These batteries don’t like heat and don’t like sitting, and I suspect they weren’t very healthy to start with since these were from wrecked cars with unknown history.  Lesson learned!

I finished disassembling the contactor box in the parking lot while waiting for Al to show up with parts, meanwhile I’d had a lot of people walking through the parking lot seeing the mess and asking questions.  Some were impressed, some were scared I was going to hurt myself, most were drinking.  I was amused with how many times I was offered a beer while I worked on the high voltage system.  Yikes!

Al showed up with parts around 1 am.  We transferred a bunch of stuff between my inverter and his so that this would be the exact same as mine to fit in the same package space.  That went back up front and then I began the slow process of rebuilding the contactor box.  One of the new-to-me contactors was slightly different and I needed a slightly longer set of screws than what I had.  Amazingly, another competitor that was up at 3 am or so had one I could use.  I should mention that over the weekend we had borrowed several tools and parts from several competitors; everybody was really helpful and willing to loan out tools and basic parts, that was very nice since we were especially unprepared having flown in to meet a damaged car.

By about 6 am we finally had all of the electrical together and ready for testing.  It worked!  The sun was just breaking and several early birds were out in the parking lot getting ready, applying stickers, and of course giving us the “You guys were out here all night?” as they walked by our car that was still in pieces.  By about 8 am we had the car completely reassembled and back to normal with exception to the dead batteries that we left in the car but disconnected.  I could have removed the 100 pounds of dead weight, but didn’t really want a high voltage battery left behind in the hotel room and didn’t want to have to also reinstall it before returning the car to Oregon, so I left it in there.

We got out to the track just in time for the driver’s meeting where I got an applause for “winning” the West Coast $2009 and bringing the car out for the rear $2009.  After the meeting we breezed through tech inspection, then found some shade and started cleaning the car.  We did a three stage wax, which went pretty quickly with a few of us working on it, then applied the stickers, which took WAY longer than I expected.  The car was finally ready for the concourse by about 2 pm.

The car was still acting up as a couple of switches weren’t acting predictably.  We couldn’t get the car into electric mode to go into the concourse, unfortunately, due to some technical issues and likely related to the all-nighter.  Oh well, we lost a bit of flair points there.  Then they stuck a microphone in my hand and told me to tell them about the car.  Wow, I wasn’t expecting that!!!  After pulling an all nighter and sweating my ass off prepping the car for the last 24 hours or so, I sounded like a real idiot.  I tried my best to spit out something coherent, but in retrospect it wasn’t pretty.  Oh well, lost of few more points because of that too, likely.  About two minutes into talking about the car, Per stole the mic from me so he could talk to a news channel…that was pretty embarrassing, I attributed it to my incoherent babbling.

We were done with the concourse around 2:45 and rapidly running out of time to get some autocross runs in.  There was no way we had time to get sticky tires mounted in time for the event, even though Pat had brought some down for us and we could fit them in the budget.  For our first run I asked Al McCrispin to step into the car as he had been getting some great times in with other cars and he heard about the car in the morning and told us he wanted to try it out.  He came back with a smile and said he was trying to use the two accelerator pedals to control the understeer/oversteer balance, but needed some practice.  I took the car back and went to regen the batteries, by the time I got back Al was already stuck in some other car doing laps.  Steve Hoelscher was the next hot shoe we asked to drive the car, as he’s done well with mid engined cars and was excited for a chance to drive the car, so we let him take it for a spin.  His first run matched Al’s run, but he said something came loose during the run and spooked him going into a corner.  Nothing big, something loose in the interior, my fault.  I regen’d the batteries and tossed Steve back in the car, at this point he was cutting in line with the fun runs as it was getting late in the day.  Steve cut a second off his time, down in the 35s, but this time said something else came loose in the interior.  My fault, again.  He said he was learning to use the throttled independently, but with the horrible tires and suspension it was still plowing bad into the corners.  His fourth run was the fastest, 35.3something, he came out with a smile so that was a good sign.  He said it was shocking how much it felt and sounded like a bone stock Fiero until you mashed the throttle coming out of the corners, then it would just scoot.  I wished I could have had the car better prepped for him, but consider our all night thrash to get the car back up and running, I was just glad to stay out of the DNF category.

Friday night was an early night.  After getting some food and wandering around the parking lot for a while, we were all to sleep by midnight.  Come Saturday morning, 8 hours just didn’t seem like enough, must have been the all nighter.  We got to the track a bit before 10, just as the first cars were lining up at the lights.  I got the battery voltage up to a usable level and went for an easy first pass, just hoping to get a time on the books in case we had problems as the day went on.  I think my first time was something like 14.9 with an 1/8 mile time that matched my best time at the West Coast $2009.  Not bad for half a battery pack!  As the day went on, I got a bit more aggressive with my shifts, powershifting the gas engine and leaving the electric throttle down through the whole 1/4 mile.  I also slowly figured out the launches, trying to get maximum power from both the powertrains and getting all the launch I could out of the horrible all season tires.  The first 1/8 mile was a blast, the car launched like a bat out of hell compared to most cars there.  The 60 foot times were a pretty consistent 1.9 seconds.  In the end, the last 1/4 mile pass was the fastest, 14.70 @ 81 mph.  That pass had an 8.9 1/8 mile time compared to my fastest 1/8 in CA of 9.3.  So, even though I was significantly down on battery power, just learning how to maximize what I had was gaining time.

It was really fun pulling ahead early on and then watching the higher power, lower weight cars slowly gain on me towards the end.  The Festiva raced against me earlier in the day with a 15 mph higher trap speed, but a second slower time.  I still haven’t got used to all wheels spinning when launching a Fiero…weird!  I suspect that with just sticky tires and full battery power, the car probably has low 14s in it.  Shoulda, coulda, woulda.

The battery thing was an obvious case of bad luck…with not-so-great batteries and the steep learning curve with this stuff, it was just bad luck that we smoked part of the inverter and were down on power.  Fortunately, we were able to get the EV stuff back and up running (even it wasn’t full power) and it was fun driving around the pits in EV mode.  It was also a lot of fun while everybody else was pushing their car through the staging lane to stay put and creep forward with EV mode.

The Fiero didn’t win any of the competitive events.  Actually, it did pretty horrible in the autocross, although I was happy with the drag and concourse scores.  The feather in my cap, the thing I was hoping to win more than anything, was the best engineered trophy…and I did get that.  That was definitely a proud moment.  I also got the evil alliance trophy, which was a Hong Norr cap…I don’t even know the Hong folks, but I still wore the cap home with pride.

We learned a lot over the weekend.  Of course, with more time, the car should be much better dialed in.  I could see a top ten finish possible with some more time, luck, and attention to tuning.  Now that I know how the challenge works, that alone makes a huge difference as well.  I’ve got a fair bit of wiggle room left in my budget if I want to bring the Fiero back for a rematch in $2010 that would make the Fiero far more competitive, and now that the hard part is done (the EV install) that would leave a lot more time for the little details that make the big difference.  Jessica and I will figure out the fate of the Fiero soon and decide what happens with this EV powertrain going forward.  Part of me thinks an engine swap, dampers, bushings, and rebuilding the battery pack would have made the car a solid contender for more than , the other part of me thinks that I’ve showed the potential of this type of project and maybe I should move on to something badder, better, and faster.  We’ll think on it over the next month

We should have some video and picture coming soon.  I know there were several people at the event that told me they got video and pictures of the Fiero in the events, so hopefully some of that will surface soon.  I was really bummed that I didn’t get more time to check out the other cars and talk to the competitors, our last minute thrash to rebuild the car took almost all of my time and energy that would normally have gone to helping others out and just shooting the bull in general.  Hopefully next year I can give it another go and avoid the catastrophic issues.

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