Thread: Electrathon - A Different Kind of "Hotrod"

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I'm squirreling away the carbon. If you decide to try it, let me know. It's near exactly the same as fiberglass.

OK, I have to brag a little more... April 27th was the big annual race at Pensacola Five Flags Speedway. The hastily repaired USF #48 car won again! Cars and teams come to this race from all over the southeast and the competition is intense. Here's where I get to brag - (1) Florida cars took the top 4 spots and (2) I built 3 of those cars!

We ran the last race of the 2018-2019 season at the Florida Solar Energy Center this past Saturday, May 4. Only three cars signed in to compete in the Open Class. Then there is good news and bad news. The bad news is the rough track broke a bolt in my front suspension, causing the left front suspension to collapse, and I only completed 13 laps in the first race. The good news is I won anyway! The second place car broke a wheel after only 11 laps and the third car failed to start because of an electrical glitch.
The #48 USF car won the Advanced Battery Class again and the #35 Simmons Career Center car took the High School Class.

Season results were also announced and awarded Saturday. The #48 USF car (Tampa, FL) is season champion in Advanced Battery Class. Tiger Racing car #4 (Hialeah, FL) is season champ in Open Class. Mulberry High School car #38 (Mulberry, FL) is champion in High School Class. All three of these cars turned well over a thousand laps in competition this season, proving their durability and consistency and showing their team's determination.

Congratulations!

Ditto.. Congrats Jim

Originally Posted by J. Robinson

OK, I have to brag a little more... Here's where I get to brag - (1) Florida cars took the top 4 spots and (2) I built 3 of those cars!

Then there is good news and bad news. The bad news is the rough track broke a bolt in my front suspension, causing the left front suspension to collapse, and I only completed 13 laps in the first race. The good news is I won anyway! The second place car broke a wheel after only 11 laps and the third car failed to start because of an electrical glitch.
All three of these cars turned well over a thousand laps in competition this season, proving their durability and consistency and showing their team's determination.

We have a different definition of durability than you folks...

Just funnin' with ya Jim. Congrats on all the success this season.

Originally Posted by J. Robinson

OK, I have to brag a little more... April 27th was the big annual race at Pensacola Five Flags Speedway. The hastily repaired USF #48 car won again! Cars and teams come to this race from all over the southeast and the competition is intense. Here's where I get to brag - (1) Florida cars took the top 4 spots and (2) I built 3 of those cars!

...and I built the other one! (Got 2nd place)
Jim, I have been racing Electrathon for four years now and while I have only raced against you personally once, I have been chasing (and sometimes been chased by) your cars the whole time. I'm pretty sure that every race I have been in has had a Robinson car in the top five finishers. I have definitely learned a lot from your build chronicles and have included several of your tips and techniques into my cars.
Thanks for the education!

Welcome to Club Hotrod, Steve. Lots of great "car people" and "gear heads" here. Congratulations on your performance at Pensacola. Everybody likes pictures; maybe you can post some pics of your car here when you get time?

I'm getting old and don't know how much longer I'll be racing, but maybe we'll get to race each other again before I quit. Thanks for the compliments and, if I can pass on any useful info to you, just ask.

It looks like you may be competing against some of my cars for some time to come. On the weekend of June 29-30 I have six people coming to learn what I do, how I do it, and why I do it that way! I don't really have any secrets, but some folks seem puzzled by my methods. Or maybe they just lack confidence to try on their own. Regardless, I'm going to teach six people the basics of how to build an Electrathon car. I know it's short notice, but we'd love to have you here if you could come. If so, contact Charlie Harrison about accommodations, etc.

If you've been following this thread (or looked back at some of the recent posts), you are aware that I have experimented with 3-wheel independent suspension on my last few cars. I can now report my findings (opinion)…

I originally built the blue flame car because the previous season (at the Cocoa race you attended) I got so beat up on the course at the Solar Energy Center in the first race that I quit the second race at 16 minutes while leading my class! The blue flame car worked great at keeping me from getting beat up on that same rough track the following year and I was leading with 3 minutes to go when I popped a tire... Then, last September, one of the schools needed a car quickly so they could make the first race of the season and it was all I had available, so I sold it. I built another one of my "Silver Bullet" design cars but with that same suspension. It performed perfectly at its first three races this past season and won my class all three times, but broke at the last race (the rough Cocoa track again). I have repaired and improved the part that broke, but I have determined that in future builds suspension will be limited to the rear wheel only. Why? Because it's the rear wheel that beats up the driver! You can dodge the big bumps with the front wheels, but the rear wheel is right behind and under your head and upper body and it has the greatest effect on your comfort.

Electrathon has been and continues to be a learning experience, but most of all it's fun! Keep in touch.

I'm amassing a nice stock pile of carbon fiber cloth. I'm sure at least one roll is destined for your electrathon car.

OK, I'm back to report that the summer training session went very well. The students and I built a second frame jig - a duplicate of the one I already have - and then built two Silver Bullet frames. One frame was complete with motor mount and all steering components - it belongs to Electrathon of Tampa Bay (ETO). The second frame was paid for by Rodney Schreck from Miami (my teaching assistant) and will become his new Advanced Battery class car. We accomplished everything in the course of two 10-hour days. We may do an extended seminar in the future where I can teach some of my body fabrication methods. I don't have any secrets; some of my students admitted they just hadn't had the confidence to try building a car on their own before.

We had our first race of the new season on Saturday (9-21-19) at Hillsborough Community College. I won the Open Standard Battery class by 7 laps over my good friend Rodney Schreck (109 to 102). After the second race Rod discovered a hot connection on one of his battery cables, so it was likely drawing too much voltage and causing a power loss. We usually finish on the same lap within a few yards of each other on this track.

At our next race I will be trying my luck in the Advanced Battery class. Rodney and I are both going to give some new Lithium battery packs a try. The difference is the Lithium battery pack is 62 pounds lighter than the twin Optimas that I'm accustomed to and double the voltage! It may take a few races for me to get the hang of this new combination - different gear ratios, lighter weight, faster acceleration. I'll report here, of course, success or failure.

Very nice Jim! Those lithium batteries sure last a long time and up here in the winter the cold doesn't effect them much either.

.

Originally Posted by J. Robinson

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At our next race I will be trying my luck in the Advanced Battery class. Rodney and I are both going to give some new Lithium battery packs a try. It may take a few races for me to get the hang of this new combination - different gear ratios, lighter weight, faster acceleration. I'll report here, of course, success or failure.

And we sure do appreciate your efforts giving us those reports / updates.

Originally Posted by 34_40

And we sure do appreciate your efforts giving us those reports / updates.

What he said.

Well, it could have been worse... Yesterday (10/12/19) I ran with the Lithium batteries for the first time. First, I was amazed at the difference in acceleration! Being 62 pounds lighter (11 versus 73 pounds of battery weight), having twice the voltage (48 instead of 24), and a big change in gear ratio made the acceleration absolutely impressive! I took it easy at first and waited until I had a clear track ahead. Then I twisted the throttle up and, after a momentary jolt of acceleration, everything went dead! The car shut off, the gauge panel went blank... nothing... The USF college guys came to the rescue and pushed me to the pits. When I told them everything went dead after I accelerated, they told me to shut off the master power switch and turn it back on. I did, and everything came back! They explained that the BMS (Battery Management System) built into the battery pack shut the power off to keep it from over-discharging and doing permanent damage to itself!

OK, so I had to make sure when I'm accelerating that I don't exceed 30 amps for more than 1.5 seconds! Back on the track and gently accelerating, I set my speed at a comfortable 28 mph. One of the other cars in Advanced Battery class (there were 4 of us) had a mechanical issue and dropped out early, so I finished 3rd in the first race. I had run a total of 87 laps to the winner's 117.

During the break between races, the USF guys offered to reprogram my motor controller so it would be less likely to shut off unexpectedly again. After they finished we ran the car for a few seconds on the jack. Everything seemed OK. At the start of the second race my car was dead! Wouldn't do anything! I had power; the gauge panel was working, but the car wouldn't go. The USF guys pushed me back to the pits as the race was starting. We ran the car on the stand again, so what was wrong? They had incorrectly set the "over voltage protection" in the controller program. I climbed back in the car and they gave me a push-start - it worked! Unfortunately, the reprogramming had also limited my top speed to 23 mph. Crap!! Oh well, at least I finished. The same car that had mechanical issues in the first race had a worse problem in this race; with about 9 minutes left he blew a tire, ran off in the grass, and rolled over. I ended up 3rd again, so I got 3rd place in the Advanced Battery class for the day. OK, so I profited from someone else's misfortune, but at least I came home with a trophy.

I will get the bugs worked out of the controller and learn the idiosyncrasies of Lithium battery packs in a couple more races. When I do I think this is going to be fun! At the very least, it's going to be a learning experience.

Very Interesting.. The battery has built in protection. I guess like any new technology there are things to learn and "tinker with"..

I think it's called the new car blues!?!?! LOL.

Thanks for sharing your new battery experiences! I'm not knowledgeable enough about electronics to know, but it makes me wonder if you couldn't have an amp draw input, and then do a feed forward power demand with an amp limit feedback to trim just a shade below 30 amps. Then a "turbo" button that pushes an unlimited demand, trimmed to 1.4 second pulses? Just messing, but I'll be interested to hear how you solve your BMS programming to crank your speed while protecting the batteries. Cool stuff!!