Hello to All,
OK, it’s now been one week since the NEDRA Nationals, so most already know that the Zombie laid down record ETs approaching (but not hitting) the 9s with four runs in the 10.2xx @ 123.xx mph range, and on the same weekend the Zombie also became the 1st street-bodied (or street legal) electric car to ever run faster than 125 mph in the 1/4 mile…but this story has already been told. What’s not yet been told, is the chain of EVents that led up to all this. It seems that immediately preceding any successful racing EVents, at least in Plasma Boy’s case, there’s always some kind of drama-trauma that has to be played out. You know that saying ‘We blow things up, so you don’t have to!’? Well, it’s safe to say I lived up to that mantra! It has always been my policy to help others learn from both our accomplishments and the mistakes we (I) make along the way. Though this is sure to be another long-winded Waylandesque tale, I’ll give you the ending up front for those who may not wish to wade through this post, summed up as follows:
- Because of a controller cabling error, the Zombie was insanely powerful but a nearly uncontrollable beast!
- Because of a controller cabling error, we learned that ‘Cool Hand Luke’ Tim Brehm has terrific sphincter control!
- Because of a controller cabling error, the Zombie had worse 60 ft., and higher ET numbers.
- Because of a controller cabling error, the Zombie blasted through the 125 mph barrier and into the Roger Hedlund 125 mph club!
- Because of a controller cabling error, we discovered just how much power the Dow Kokam batteries could make!
- Because of a controller cabling error, we learned that a Zilla Z2K can output 3000+ amps and live through it!
- Because of a controller cabling error, we learned that Jim Husted’s Siamese 9 can handle 3000+ amps and live through it!
- With the controller error corrected the Zombie posted the quickest and fastest 1/8 mile numbers of any street legal electric car!
- With the controller error corrected the Zombie posted the quickest 1/4 mile ET of any street legal electric car!
OK, on with the story…
Team member Gaylen Aust wrote:
Some nut that changed the Zilla the week prior for reasons I will not say had reversed 2 motor leads that caused it to not current limit.
That would be me
It all started out quite innocently, really. I had been out in the Wayland EV laboratory the week before the NEDRA Nationals, all by myself and in quite a relaxed mood as I was tidying up things on the car, checking this and that out to make sure the car would be ready for the following week’s racing weekend. I decided to freshen-up the 12V system’s 13.4V battery and hooked up a charger to a connection point under the hood, as I’d done many times before. There was a design flaw at the main 12V circuit breaker that I had made note of and needed to change to avoid a possible electrical catastrophe. It was wired in a fashion where the 50 amp Anderson charger input port was on the load side while the battery positive cable was on the other. Connected this way, if the breaker was flipped ‘open’ the charge port was disconnected from the battery while still being connected to ‘certain’ 12V loads. It was a simple error I had made where the 8 gauge loop end connector off the positive leg of the Anderson connector was secured to the wrong side of the circuit breaker…I knew about it and was going to get it changed around, but then I forgot to actually do it. No problem, because as long as the breaker was closed the charge port was connected to the battery B+. Because of the 13.4V battery’s need to go to 16+ volts to get a full charge and because other more important items on the car took precedence over finishing a dedicated charger for this battery, I had gotten lazy and would connect a mighty PFC50 charger to the 12V system’s charge port. Continuing the lazy theme, I didn’t bother to readjust the fully charged voltage set point either, because I never charged it this way without being ‘right there’ watching both charging amps and the rising battery voltage and being ready to shut it down manually. I know, I know, it was a bad idea.
So anyway…I had just plugged the 50 amp Anderson extension cable from the PFC50 into the car, set the current knob to a low area, and flipped the charger’s breaker on. I had walked away and was on the other side of the shop when I heard a sound that made my stomach ache…’BZZ-ZAPP-ZORCH’!!!!! This all too familiar sound was accompanied by a mini mushroom cloud rising from of all things, the Zilla’s Hairball! As I rushed to get back to the charger’s breaker the sounds worsened to where I could hear popping noises that resembled fire crackers going off as the acrid smell of vaporized silicon filled the shop air! Once I had the power shut down, the Hairball continued to sizzle and smoke …it ‘was not’ a good situation I had of course, failed to close the car’s 12V system breaker, thus the PFC50′s output was unloaded and had sent 480+ volts through the Hairball! In the horror of the moment my thought turned to the charger – had I blown it up as well? They are known to not like being unloaded. My mind then switched to the Zilla itself. Could the unleashed high voltage have traveled through the data cable and into the Zilla’s internal electronics board? Man oh man, this was definitely not a good situation! It was late at night, I had to go to work early the next morning, and so after waiting to make sure nothing might erupt into flames, I closed down the shop and went back to the house to go to bed. Yes, I actually had nightmares about what I had done.
Following work the next day, I went back out to the shop to do a post-mortem. Pulling the still-pungent smelling Hairball and carrying it to the workbench, a couple of good shakes turned this Zilla control box into a fairly effective maraca. Inside, it was as ugly as it gets Bye, bye, Hairball! No problem, I’m a quad Zilla guy – got a Z2K in the Zombie, a Z1K in the Meanie, a spare Z2K on the shelf and next to it a spare Z1K. Oh-oh, wait…that’s right, I had loaned my spare Z2K to Madman Rudman…no wait, it had come back on a ride south from Seattle to Portland with Mike Willmon…no wait, inside the box was the Z2K but no Hairball…oh yeah, that’s right, he had kept the Hairball but returned the Zilla…damn! Hey, that’s OK, there’s still that brand new Z1K in the box…I’ll use its Hairball. And so I did – got it all mounted and hooked up, had the car up on jack stands, then tried to power things up…silence, no ‘click’ of the main contactor, and a glowing error light on the Hairball Oh no, had the high voltage of the 12V line made its way to the Bubba contactor’s coil? These babies go for a cool $1000 nowadays – time to meter-out the coil. Whew, Bubba OK and clicks in nicely with an external 12V input – OK, dodged that bullet. Checking the codes of the Hairball, one kept cropping up, the dreaded ’1132′ code ‘Controller did not communicate during precharge’! Calls on the secret Bat Cave line to Otmar were ‘interesting’ and to my surprise, my longtime friend didn’t scold me at all – whew! He didn’t feel the high volts would have migrated down the data cable into the Zilla to damage things, but subsequent tries at everything to wake up the Zilla failed – more of that sick stomach feeling. Time to pull the other Z2K out of the box. Removing the shock therapy brain dead Z2k, I took the time to clean off the power cables to make them conform to my wiring neatness standards, as someone had marked them with goofy white dots from a white-out pen…note to self: sometimes having cables clearly labeled is a good thing. Once the backup Z2K #2 was mounted and hooked up, the car woke up on 1st try and all was well again – well, except for one fried Hairball and a dead Z2K. At this point I am now down to no spare Z2K with a racing weekend approaching, and a Z1K minus its requisite Hairball interface.
A new problem arose though, when trying to feather-on the throttle, as the motor would instead jump to a fast idle type rpm, then after that not-so-subtle ramp up, it was very controllable…hmmm. I left the car up on the jack stands. Monday night, Sept. 6, after we were both off work, Gaylen showed up to pull the rear end so we could do the 3:70 to 3:50 gear swap…the races were just 4 days away. Gaylen lives very close to our great sponsor FabTek, so before starting work Tuesday morning, he delivered the rear end to FabTek’s Bob Wescot could set up the Strange differential with the new gear set. Bob had previously sent the 3:50 gear set out to have the same special low friction process done to them, as we had done to the 3:70 set. The 3:50 gear set was not new…they had been given to me from a friend who runs an 8 second class rail dragster, and the set actually came from his friend who races in the same points series – nice gasser guys who just wanted to see the little Datsun go quicker and faster Trying to avoid last minute work on the car, we had hoped to get the diff. back Tuesday night, but business is good for FabTek right now and Bob couldn’t finish it until the following day, Wednesday. Bob had trouble getting to the job on Wednesday too, but being the good guy he is, he stayed late finishing it by around 7 pm! Gaylen picked up the rear end in the early-evening, then arrived at my place to put the rear axle assembly back together. Spinning things up with the car still off the ground, we were both taken back by a very loud gear whine…I mean LOUD! Just what I needed, more problems just before a big NEDRA race weekend!
Thursday, the day before the races, Gaylen and I took the car out for ride to see if the gears would be safe to run on. From Gaylen:
…we head down the road and he just barely gets into it and the back kicked out and the car just took off. I can say that I have never been in a car that accelerated that fast it was insane but so much fun.
Yes, the Zombie had more power than I had ever experienced! It was weird though, because other than the slight lurch on what would otherwise have been a butter-smooth take-off, the car was easily driven with smooth throttle response – but when you pushed your foot down harder, there seemed to suddenly be hundreds of horsepower more! I know, many of you are thinking, “For crying out loud, it’s a 10 second street car”, but trust me on this, it felt way stronger than that! At the time, we couldn’t quite figure it out, and so chalked it up to the gear ratio change…silly us! Back in the EV shop, opening the trunk to check the batteries out, I was quite surprised to see many red LED low voltage set point lights on…what the heck? I had the battery current limit set to 1500 amps. With the low volt set point adjusted to 2.8V per cell, even with 1800 battery amps dialed in, they had never come on before, why were they coming on now? With the charger connected and cranked to 29.7 amps, the pack was initially at 396V (a cool 11.7 kW charge rate) and it quickly came back up to 400V at low current as all the green bypass LEDs winked, reset the BMS, and knocked out the red LED low volt indicators. Hmmm…it didn’t take much of a charge to turn off the telltale red LEDs, so the pack was never at a low SOC…hmmm.
Friday arrived with c-cold temps, dark grey skies, and a chill in the air that promised a night of poor traction at the track. July’s mid 90 temps were a warm memory, it was September now and summer was definitely slipping through our fingers here in Oregon. Though forecasted to be in the low 70s, I think it never got any warmer than just above 60 degrees. By the time we arrived the track it was early evening and the temperature was down to the mid-50s. The conditions were bad with a cold track surface – even the low hp street cars were having traction problems.
Our first run of the night was at 7:28, a run I’ll remember for a very long time. Steve ‘The Taunter’ Schrab had picked a hot Firebird running 11s as our first match up. Realizing traction was going to be an issue, Tim and I discussed the importance of getting the tires as hot and sticky as we could, so the burnout was spectacular! Tim didn’t waste any time staging so as to keep the tires warm, but when the tree sent him on his way, instead of our usual ‘stick & go’ hole shot, the Zombie instead lit up the G Force drag radials like a funny car! The Firebird got a decent 1.748 second 60 ft., while the Zombie’s fog show gave us a miserable 2.480 second 60 ft. The Firebird left the Zombie far behind and roared on to a quick 11.697 ET, while the Zombie’s tires kept smoking – 40,50,60,70,80 mph and they’re still boiling! I’ve had this car at speed with the tires breaking loose – not a good situation in a short wheel base car, and I knew what was coming next as the blood surely drained from my face. Then it happened. The Zombie pitched sideways then fishtailed as it tried to get away from Tim, but he would have none of that and he expertly kept control of the car. The gasps from the bleachers turned to cheers as the Zombie rocked to a full stop, albeit a bit sideways out on the track. Tim then planted his foot back down to show the car who was boss, and even after coming to a full stop, managed to run 14.553 @ 113.06 mph.
Back in the pit area the Firebird driver joined us, wondering what had happened to the little electric car he was convinced was going to blow him away, as we all tried to regain our composure after such a scary run. Laptop screens were glowing while connected to the Zombie gathering data, but there other things glowing as well – those red LED low volt telltales again. Bruce ‘Doc’ Sherry’s wonderful Manzanita Micro BMS system had the evidence we were looking for and showed that the stout Dow Kokam cells had dipped to 2.44V! What?? It takes HUGE amounts of current to make them dip that low! What was going on here?
We reduced the battery amps and motor amps numbers in Hairball, and sent Tim back to the track, where at 8:12 he was staged at the tree. Things were still not right, as the tires refused to grip, we got another 2+ second 60 ft., and we still could not get back into the 10s with an 11.008 @ 122.28 mph pass. The only good thing was that trap speed of 122 mph, the fastest the Zombie had ever run in the 1/4 mile.
Back in the pit we again saw the red LEDs, but the Dow Kokams had not broken a sweat and were barely warm to the touch. We force-cooled the motor with cold compressed air and looked at data again, Dr. Sherry looking at BMS info and ReVolt’s Mark Farver looking at the DAQ4 Hairball info. Mark tired to tell us about the odd fact he was not seeing ‘any’ amperage readings and that they all came in as ’0′…hmmm. Should have listened to him. Meanwhile, the rest of us ampheads were adjusting tire pressure for the next run.
At 9:26 Tim and the Zombie were back on the line while the rest of us were zipping up our hoodies trying to stay warm. Another poor launch at 2+ seconds 60 ft. and another 1/8 mile at over 7 seconds, but in spite of smoking tires and constant wheel spin we finally got back to the 10s with a 10.846 @ 124.91 mph pass. Though nearly a half second slower than July 30th’s record 10.40 run, we had just raised the bar for an electric street car trap speed and by the narrowest of margins had just missed getting into the 125 mph club! It looked like the decision to go taller to a 3:50 gear ratio was the right choice. Back in the pit area once again, we saw the red LEDs. A quick recharge turned them back off, so again the pack was not depleted in any way…hmmm.
The car was back at the tree at 10.08 for what would be the final run of the night for us. It was just too cold, the track was not being cooperate traction wise, and the Zombie was still a real handful to keep straight. We were all concerned for Tim’s safety and I was ready to pull the plug if things got worse…and they did! I think Roderick Wilde covered this better than I can:
The Zombie had been having massive traction problems all night. Tim was trying to get the tires a bit stickier, but the batteries didn’t care. When he launched it still boiled the the tires until it hit about 80 mph and then came up into one of the best wheelstands I’ve seen in years. It was long and drawn out and came down like the nose on on jetliner on landing, nice and easy, and shot straight forward. It crossed the eighth mile at 108.57 mph. At this time it had left the nitrous enhanced Dodge Charger in the left-over tire smoke from the launch. He crossed the finish line and into the history books as being the first street bodied car on this planet to break 125 mph with a speed of 126.01 mph. This put the car firmly in NEDRA’s Roger Hedlund 125 mph club.
The ET was the best of the night at 10.542 and though the Zombie easily took out the 500+ hp Nitrous Hemi Charger, it was still not as good as we had done back in late July (10.400). As Rod pointed out, we at least set a new number for street EVs in terms of trap speed….still, it’s the ET that counts. After the power wheelstand at speed where the ~ 80 mph wind under the car appeared to have kept the car’s nose floating in the air (visions of the car lifting higher and flipping over), I had seen enough and made the decision we would not be going back out. There was a new forecast calling for mid 70s on Saturday, and with the prospect of a warmer and hopefully stickier track, we were determined to return the next night to get the job done.
To be continued…
See Ya…John ‘Plasma Boy’ Wayland