Fun and cheap EV racing series open to everyone

[ProEV]

Greeting EVers,

I do not have the budget for Formula E, and I am not convinced SCCA’s Prototype Electric class are the way to go- though full credit to Dayle Frame and the EVAC for their work on the difficult task of writing those rules.

Instead, I am involved in racing electric vehicles in Electrathon which is kind of the electric version of Karting but with more open engineering rules. The cost is a lot less than car racing, the track time is more, and there is a lot of wheel-to-wheel action. It is a fun and cheap way anyone can experiment with EV’s.

The driver is required to weigh or be ballasted to 180 pounds or over. Maximum battery weight/capacity is specified-15 lbs./1,000 Whrs if you are running lithium. Three or four wheels. Then there are some basic safety design rules for driver protection. And that is pretty much it.

Hub motors. All-wheel drive. Leaning suspension. Rear wheel steering. Whatever you want to try. The winning cars tend to keep it simple but do it well. Rear wheel drive Tadpole trikes (two wheels in front). Bicycle wheels. Reasonable camber. Here is a description of my vehicle: 2022-23 ProEV Super Coupe Description

We race on a variety of tracks including ovals and permanent road courses but most of the races are tight tracks set up in parking lots. This puts a premium on driver skill and keeps the cars close together.

I regularly pull 1.7 Gs cornering. Most courses the speeds are under 45 MPH. Here is a brief video of the ProEV Super Coupe in action. It is a 360 video.

I prep my own car. It is light enough to move around without help. Alignment, corner weights, mount two sets of tires, clean and lube chain, charge and balance pack, nut and bolt. That is pretty much all that is required for a race day. 4-6 hours work? Of course, making ‘improvements’ can use up more time.

I transport using a small open trailer and hitch it to my Prius. I drive up the night before the race and drive home at the end of race day. Entry fee is $40. I use a set of tires each race day so around another $45.

We race on a Saturday. The races are 1 hour long. Normal schedule is: 20 minute Practice, Race one, lunch break, 20 minute Practice, Race two, Trophies then head home.

There is a High School class and an Open Class. Those classes are subdivided into Lead Acid and Advanced Battery. All the classes run together.

Like most series, buying a used chassis is the way to go. The ‘want to buy’ section of this website is a good place to post: https://electrathonamerica.activeboard.com

A car can be built for as cheaply as $1,300 if you have some fabrication skills. Video here:

Other examples: 1HP Electric Car And here: https://www.electrathonamerica.org/jim-robinson-silver-bullet

There are a couple of new car builders out there as well. Blue Sky Design - aerocoupe kit and ElectrathonParts.com.

I am running in the Electrathon of Tampa Bay series. ELECTRATHON OF TAMPA BAY | ELECTRATHON RACING The season runs from September to May with about one race per month.

There are races in Georgia and Alabama Georgia Electrathon. Texas, Kansas, and Connecticut all have had races. There used to be an active group of racers in California and Oregon, but the pandemic disrupted their organization. There must be a number of fast vehicles sitting around in that area. This is what the racing looked like out there ten years ago at PIR:

and road racing at Hood River in 2016.

This race is around a brewery. I would happily commit to running in this race if someone restarts it!

The overall sanctioning body is here Home | AMERICA | The Official Electrathon America Site

 

[nicobie]

This sounds like fun. I hope you are able to keep it going.

 

[gogo]

Anecdotal racing story: 1975, my father was selling Zagato Elcars and entered a hopped-up car as 'exhibition' in a timed (slalom?) SCCA event. Despite stopping and backing up when he got on top of a cone (he didn't want to have to pay for it), he still had a competitive time. In the next event, electrics were specifically not allowed in the regular class.

 

[The Toecutter]

My goal is to basically build a "street legal" Electrathon-like car. Street legal as a motorcycle or autocycle, but functional as a microcar.

The potential for a sub-150 lb vehicle that can run sub-12 second 1/4 miles, and do 200+ miles range at 70 mph on a 3-4 kWh battery, top out at well over 100 mph, with AWD, is definitely there with off the shelf ebike parts for a one-seater enclosed 3-wheeled vehicle built with velomobile aerodynamics. Such a thing in theory could be mass produced for the cost of a scooter or moped, and even furnished with basic comforts like heating and air conditioning. When you consider the technology that exists but isn't yet available for sale, much faster than 12 second 1/4 miles is possible, but that's still a good starting point.

 

[harrisonpatm]

do 200+ miles range at 70 mph on a 3-4 kWh battery

That's 20wh/mile off a 4kwh battery. At 70mph? Not sure that's possible. If so can you share how you're coming up with that estimation?

 

[The Toecutter]

That's 20wh/mile off a 4kwh battery. At 70mph? Not sure that's possible. If so can you share how you're coming up with that estimation?

A basic physics lesson for you.

Assume a total vehicle payload including operator of 200 kg, tires with a rolling resistance coefficient(Crr) of 0.006, drag coefficient(Cd) of 0.09, frontal area(A) of 0.5 m^2, hub motors in all three wheels with an assumed 85% operating efficiency(Em), and an assumed 98% efficiency transferring power to the motors(Et).

V = 70 mph = 31.3 m/s
G = Gravitational constant = 9.81 N/kg
Rho = Air density = 1.25 kg/m^3
1 Newton = 1 kg-meter per second squared
1 Watt = 1 Newton-meter per second

Force to overcome rolling resistance(Frr):

Frr = M * Crr * G = 200 kg * 0.006 * 9.81 N/kg = 11.77 N

Force to overcome aerodynamic drag(Fa):

Fa = 1/2 * Rho * Cd * A * V^2 = 0.5 * 1.25 kg/m^3 * 0.09 * 0.5 m^2 * 31.3 m/s * 31.3 m/s = 27.55 N

Power to overcome both forces of rolling resistance and aerodynamic drag(Pf):

Pff = (Frr + Fa) * V = (11.77N + 27.55N) * 31.3 m/s = 1,230.71 W

Power demanded from the battery pack(P):

P = Pff / Em / Et = 1,230.71W / 0.85 / 0.98 = 1,477.45W

So 1,477.45W to cruise 70 miles per hour?

1,625.13W / 70 mile/hour = 21.1 Wh/mile




Now, in the real world, I have a Milan SL velomobile with a Cd value of 0.08 and a frontal area of 0.41 m^2, using Continental Contact Urban tires with a Crr value of 0.005. It has a mass of 30 kg, and with me in it plus my tools/food/water, is around 100 kg all up. I can pedal it to 50 mph on flat ground in a sprint, entirely unmotorized, with a pedal drivetrain efficiency of around 95%.

For motorized vehicles, there are solar car tires with Crr values as low as 0.003, and practical road-going tires with Crr values around 0.006 that have emphasized efficiency.

Such a vehicle is very much doable. The above hypothetical vehicle outlined would have a 1m wide front track, necessitating more frontal area, and it would be reclined and low, with a height around 0.7m, a roll cage integrated in it, DOT rims, hubs, tires, hydraulic disc brakes on all three wheels, and one could fit a 8 kg Leafbike 1500W 3T motor including hubsink and ferrofluid in each 16" DOT wheel, each fed about 10 kW peak power. The battery pack of a bit over 4kWh, using a quantity of 280 Molicel P42 21700 cells, including battery housing, would weigh around 22 kg and be capable of making at least 30 kW continuous power until the cell is at its 2.5V cutoff, enough power to burn the motors out if you aren't careful.

Each motor could have a 144V PowerVelocity controller each weighing 1 kg running it with a setting of 150A max phase current. The controllers would be very under-stressed, and a CycleAnalyst computer could run the whole thing. This thing would have enough power and torque for its mass to play with Dodge Charger Hellcats at the drag strip, and the motors would have an appropriate voltage and winding for this vehicle to top out at over 120 mph. 0-60 mph time would be somewhere around 3.5 seconds.

A vehicle like this, if mass produced, could easily come in at well under $10,000 with functioning electronics, turn signals, rack and pinion steering with collapsible steering column, lights, safety harness, gauges, wipers, ceramic heating element for operator comfort in cold weather as well as defroster, and all the basics needed to be a functioning "car". It could have trunk space comparable to a Mazda Miata, maybe a little more. Unlike an ebike or motorcycle, the operator would stay dry in the rain and with AWD it would be controllable in the snow and ice. Steel and fiberglass could compose the chassis/roll cage. It would be not as safe as a conventional car, but MUCH safer than operating a motorcycle/bicycle/ebike/scooter/moped in a collision, and probably safer than almost any car made before 1980 if you design it right. Total vehicle weight ready to drive, but unladen with rider/luggage would be around 150-200 lbs.

 

[harrisonpatm]

A basic physics lesson for you.

Assume a total vehicle payload including operator of 200 kg, tires with a rolling resistance coefficient(Crr) of 0.006, drag coefficient(Cd) of 0.09, frontal area(A) of 0.5 m^2, hub motors in all three wheels with an assumed 85% operating efficiency(Em), and an assumed 98% efficiency transferring power to the motors(Et).

V = 70 mph = 31.3 m/s
G = Gravitational constant = 9.81 N/kg
Rho = Air density = 1.25 kg/m^3
1 Newton = 1 kg-meter per second squared
1 Watt = 1 Newton-meter per second

Force to overcome rolling resistance(Frr):

Frr = M * Crr * G = 200 kg * 0.006 * 9.81 N/kg = 11.77 N

Force to overcome aerodynamic drag(Fa):

Fa = 1/2 * Rho * Cd * A * V^2 = 0.5 * 1.25 kg/m^3 * 0.09 * 0.5 m^2 * 31.3 m/s * 31.3 m/s = 27.55 N

Power to overcome both forces of rolling resistance and aerodynamic drag(Pf):

Pff = (Frr + Fa) * V = (11.77N + 27.55N) * 31.3 m/s = 1,230.71 W

Power demanded from the battery pack(P):

P = Pff / Em / Et = 1,230.71W / 0.85 / 0.98 = 1,477.45W

So 1,477.45W to cruise 70 miles per hour?

1,625.13W / 70 mile/hour = 21.1 Wh/mile




Now, in the real world, I have a Milan SL velomobile with a Cd value of 0.08 and a frontal area of 0.41 m^2, using Continental Contact Urban tires with a Crr value of 0.005. It has a mass of 30 kg, and with me in it plus my tools/food/water, is around 100 kg all up. I can pedal it to 50 mph on flat ground in a sprint, entirely unmotorized, with a pedal drivetrain efficiency of around 95%.

For motorized vehicles, there are solar car tires with Crr values as low as 0.003, and practical road-going tires with Crr values around 0.006 that have emphasized efficiency.

Such a vehicle is very much doable. The above hypothetical vehicle outlined would have a 1m wide front track, necessitating more frontal area, and it would be reclined and low, with a height around 0.7m, a roll cage integrated in it, DOT rims, hubs, tires, hydraulic disc brakes on all three wheels, and one could fit a 8 kg Leafbike 1500W 3T motor including hubsink and ferrofluid in each 16" DOT wheel, each fed about 10 kW peak power. The battery pack of a bit over 4kWh, using a quantity of 280 Molicel P42 21700 cells, including battery housing, would weigh around 22 kg and be capable of making at least 30 kW continuous power until the cell is at its 2.5V cutoff, enough power to burn the motors out if you aren't careful.

Each motor could have a 144V PowerVelocity controller each weighing 1 kg running it with a setting of 150A max phase current. The controllers would be very under-stressed, and a CycleAnalyst computer could run the whole thing. This thing would have enough power and torque for its mass to play with Dodge Charger Hellcats at the drag strip, and the motors would have an appropriate voltage and winding for this vehicle to top out at over 120 mph. 0-60 mph time would be somewhere around 3.5 seconds.

A vehicle like this, if mass produced, could easily come in at well under $10,000 with functioning electronics, turn signals, rack and pinion steering with collapsible steering column, lights, safety harness, gauges, wipers, ceramic heating element for operator comfort in cold weather as well as defroster, and all the basics needed to be a functioning "car". It could have trunk space comparable to a Mazda Miata, maybe a little more. Unlike an ebike or motorcycle, the operator would stay dry in the rain and with AWD it would be controllable in the snow and ice. Steel and fiberglass could compose the chassis/roll cage. It would be not as safe as a conventional car, but MUCH safer than operating a motorcycle/bicycle/ebike/scooter/moped in a collision, and probably safer than almost any car made before 1980 if you design it right. Total vehicle weight ready to drive, but unladen with rider/luggage would be around 150-200 lbs.

Looks like it works on paper, sure. With no variables, of course. No hills, winds, less-than perfect roads. And my other concern is that in order to get the vehicle's weight down far enough for those specs, I would feel terribly uncomfortable cruising around at 70mph on a frame that weighs less than me.

Skepticism aside, if you were to make this and it doesn't meet it's range and speed expectations as suggested above, I would still be incredibly impressed. Hypothetically, if you were shooting for 200 mile range at 70mph, and only ended up with 150 mile range at 60mph, holy crap, that would still be awesome on its own. I certainly couldn't build anything like that. I look forward to following that build thread if it comes to fruition.

 

[The Toecutter]

Looks like it works on paper, sure. With no variables, of course. No hills, winds, less-than perfect roads. And my other concern is that in order to get the vehicle's weight down far enough for those specs, I would feel terribly uncomfortable cruising around at 70mph on a frame that weighs less than me.

Skepticism aside, if you were to make this and it doesn't meet it's range and speed expectations as suggested above, I would still be incredibly impressed. Hypothetically, if you were shooting for 200 mile range at 70mph, and only ended up with 150 mile range at 60mph, holy crap, that would still be awesome on its own. I certainly couldn't build anything like that. I look forward to following that build thread if it comes to fruition.

In practice, C. Michael Lewis set an Electrathon record of 62.1 mph over 1 hour, using Electrathon's standard lead acid battery configuration weighing 67 lbs and storing about 0.75 kWh. This works out to 12 Wh/mile. The car was called the Eracer.

Michigan Challenge

What I want to build is a version of that which is street legal as a motorcycle(so 3 wheels instead of 4), and has consideration for performance much as the following car does:

Watch a tiny electric race car smash the world acceleration record with a 1.46-second run to 62 mph

It would be such a beautiful thing to have something like what I describe available. It's a shame that Dave Cloud is no longer around. He was big into the Electrathon scene and him and I had a few conversations regarding vehicle efficiency on the EVDL 2 decades ago, and he had a lot of info to offer regarding vehicle efficiency. He built the "Dolphin", a lead-acid powered modified Geo Metro EV conversion that could get 200 miles range at 70 mph, before Lithium batteries were affordable or widely available. And he'd have been all over this idea.

I've already built an electric velomobile that gets 150-200 miles range on 1.5 kWh at 30-35 mph with some light pedaling, on city streets in traffic in a hilly city with lots of stop and go. I'm currently upgrading it for more top speed with a higher voltage battery pack and a more slippery body based upon the Milan SL I bought. Hoping to make a pedalable sub-100 lb vehicle that can top out at over 100 mph using the motor, and still reach 40+ mph on the flat with only pedaling. This is a good test bed for various build configurations/changes, and will lead the way to a more performance-oriented vehicle later on. I've put 75,000 miles on this trike since building it in 2016. Downhill, it has proven itself stable and controllable on bad roads at 60 mph(prior to motorizing it at that), in spite of being so light. With a 48V battery, top speed was only 50 mph or so on flat ground.

I've had the Milan up to 89 mph going down a very steep hill, but it gets twitchy after about 45 mph or so. The steering geometry and narrow front track limits its sustainable safe cruising speed potential.

 

[harrisonpatm]

In practice, C. Michael Lewis set an Electrathon record of 62.1 mph over 1 hour, using Electrathon's standard lead acid battery configuration weighing 67 lbs and storing about 0.75 kWh. This works out to 12 Wh/mile. The car was called the Eracer.

Michigan Challenge

What I want to build is a version of that which is street legal as a motorcycle(so 3 wheels instead of 4), and has consideration for performance much as the following car does:

Watch a tiny electric race car smash the world acceleration record with a 1.46-second run to 62 mph

It would be such a beautiful thing to have something like what I describe available. It's a shame that Dave Cloud is no longer around. He was big into the Electrathon scene and him and I had a few conversations regarding vehicle efficiency on the EVDL 2 decades ago, and he had a lot of info to offer regarding vehicle efficiency. He built the "Dolphin", a lead-acid powered modified Geo Metro EV conversion that could get 200 miles range at 70 mph, before Lithium batteries were affordable or widely available. And he'd have been all over this idea.

I've already built an electric velomobile that gets 150-200 miles range on 1.5 kWh at 30-35 mph with some light pedaling, on city streets in traffic in a hilly city with lots of stop and go. I'm currently upgrading it for more top speed with a higher voltage battery pack and a more slippery body based upon the Milan SL I bought. Hoping to make a pedalable sub-100 lb vehicle that can top out at over 100 mph using the motor, and still reach 40+ mph on the flat with only pedaling. This is a good test bed for various build configurations/changes, and will lead the way to a more performance-oriented vehicle later on. I've put 75,000 miles on this trike since building it in 2016. Downhill, it has proven itself stable and controllable on bad roads at 60 mph(prior to motorizing it at that), in spite of being so light. With a 48V battery, top speed was only 50 mph or so on flat ground.

I've had the Milan up to 89 mph going down a very steep hill, but it gets twitchy after about 45 mph or so. The steering geometry and narrow front track limits its sustainable safe cruising speed potential.

Very cool. Where do you live that you hope to get it street legal?

 

[The Toecutter]

Very cool. Where do you live that you hope to get it street legal?

Missouri, USA. Getting one-off builds is a lot easier to get legal here than most places.

 

[CONSIDERABLE SHOUTING]

This is really cool!

Also your website is a blast from the past, real Web 1.0 stuff.

 

[ProEV]

My goal is to basically build a "street legal" Electrathon-like car. Street legal as a motorcycle or autocycle, but functional as a microcar.

Hi Toecutter,

I like the idea of driving a sleek agile ‘Electrathon’ like vehicle on the street. It would be fun and free up resources and space compared to the basic car. Here are a couple of my favorites:

The Monoracer: Monoracer Cabin Motorcycle | Home This is like the Lamborghini of this class of vehicle; a work of art; a joy on uncrowded winding roads; a true touring vehicle. And not so well suited for popping down to the corner store; the whole landing/parking; the effort involved in climbing in and out; smudges from noses on the windows and handprints marring the perfect polish from the Hoi Polloi ogling it.

AKO P150 AKO Technical › Mobility we redefine A tilting three-wheeler would be fun to drive but this is a smaller market. The driver needs to always focus on driving and not day dreaming or trying to text.

Arcimoto FUV Arcimoto - Ultra Efficient Electric Vehicles This is the most practical of the three. It is stable and easy to drive. It is easily highway capable (80 mph). It is easy to get in and out of. I have driven one and and accelerates well and can carry speed in a corner.

Arcimoto’s biggest challenge is the ‘Chicken and Egg’ conundrum. The average person spends almost 20% of their income on transportation related costs. In volume production, Arcimoto is aiming for $12,000 price. Combined with tiny operating cost, low maintenance, giving up the rarely used ability to carry three more people and a ton of luggage might look more attractive to people. However, in low volume production, the bare bones version is $19,900 and they are probably losing money on each vehicle.

Trying to keep the price below a basic car means that you can upgrade to doors but no windows. Heated seats are standard but no Air Conditioning is available.

EV incentives could have helped but these vehicles do not qualify. It kind of misses the point to encourage people to buy resource heavy Electric SUVs and Pick-Ups, rather than low cost EV transportation.

 

[The Toecutter]

EV incentives could have helped but these vehicles do not qualify. It kind of misses the point to encourage people to buy resource heavy Electric SUVs and Pick-Ups, rather than low cost EV transportation.

The point of the policy is to keep people spending money. An inexpensive EV that costs less to operate than a gasoline powered car doesn't do that. Massive electric SUVs and luxury cars weighing 5,000+ lbs, laden with expensive features, unrepairable with basic tools, on the other hand, keep people spending ever increasing amounts of money and using ever more resources. This is the result of a paradigm of endless growth. Regulations are crafted to keep competition from interfering with what the legacy automakers have going for themselves. Taxpayer money is being used to subsidize inefficient and wasteful resource consumption via these "incentives", because this makes a small group of people a lot of money, and policy has been crafted to nudge/force peoples' purchasing habits in this direction, even if the buyers don't have the money to keep this up. There's always an 84-month payment plan, sign on the dotted line, and juggle debt burdens around...

I'm familiar with all three vehicles you listed.

None of them are going for the sort of aerodynamic slipperiness I have in mind, coupled with the static stability provided by at least three wheels. Velomobiles would be a good starting point, IMO. The Electrathon Cars did this out of necessity, and the top record holders have astounding levels of efficiency. That sort of efficiency could be replicated in a street vehicle, and to incentivize people to want one, it would be dirt cheap to give it performance that could embarrass a supercar. It would be so light you could get away with using ebike motors and controllers. AWD and 30 horsepower in a sub-200 lb vehicle that provides weather protection for the rider, enough space for groceries or luggage, and at a much lower cost than any car is definitely possible. Such a thing would use thousands of dollars less materials/parts than an Arcimoto FUV.

As 3D printing technology improves, the potential to keep labor costs low and possibly allow them to be built from a one-man operation is on the horizon. The trick is to keep the government from regulating it out of existence, because endless growth on a planet of finite resources is not a sustainable economic model, and resources are only growing more scarce as they are used up, and such a vehicle concept will eventually catch on out of necessity.

Here's pics of a prototype a friend of mine put together:

 

[nicobie]

You guys are serious about this. 1.7g in this vehicle to me is amazing!

 

[The Toecutter]

You guys are serious about this. 1.7g in this vehicle to me is amazing!

Especially considering it is a 3-wheeler. It did this without tipping over!

Being so light, making it able to get enough traction to do this is a LOT easier than a normal car, but still, it is impressive as hell. Especially since there are no drag-adding downforce enhancements. You can keep the car nice and slippery and pull this off. I want a vehicle that can corner with 1.7g. The cops wouldn't have a prayer in catching that.

 

[nicobie]

Cops always win because they are allowed to cheat.

I know what sideway Gs feel like, I have a cart background (long, long time ago, in my youth).

 

[hallkbrdz]

Maximum battery weight/capacity is specified-15 lbs./1,000 Whrs if you are running lithium. Three or four wheels. Then there are some basic safety design rules for driver protection. And that is pretty much it.

Curious - where do you have the complete rules at?

1kWh isn't much, how many laps or time do you run for a race?

 

[The Toecutter]

1kWh isn't much, how many laps or time do you run for a race?

1 kWh can do a lot if your vehicle is actually designed to use it efficiently. Modern vehicles are designed so backwards from what the laws of physics suggest they should be, all to increase resource consumption, purchase price, and operating cost. Every dollar you save is a dollar the corporations didn't extract from you. 1 kWh will get you 4 miles of travel in a Tesla Model 3 driven by boobus Americanus ghettopottamus without any concern for operating the vehicle efficiently, arguably among the most efficient platforms on the new car market today, but in a purpose-built vehicle designed rationally, could get you an order of magnitude more than that in the exact same set of operating conditions.

Cops always win because they are allowed to cheat.

Lots of Hellcat drivers rolling around with no plates/tags/registration/insurance/drivers license here. Because they know that the cops won't be able to do much about them, and their cornering prowess is nowhere near 1.7g. And I wouldn't want it any other way.

 

[hallkbrdz]

Hey I get it, it's just that safety as in size and mass is significant when driving next to semi trucks and delivery vehicles.

1kWh only gets us about 1 mile at race pace with top tier electric sprint karts on short technical tracks. Of course we have a lot more mechanical loss due to a solid rear axle and scrubbing with wider and much stickier tires, with much shorter WOT / full brake "straights" that burn power. For 120 Mph on long tracks, the noted Tesla is even MUCH more efficient than our ~0.9 Cd karts where we then plument to about 2.5kWh per mile when not in draft.

So I guess you could say we are trying to use as much energy as quickly as possible (having a lot of fun along the way)... on a budget. Energy costs are the least of the overall costs, electric or otherwise. At least we don't have to rebuild the 2-stroke engine after every race.

 

[The Toecutter]

Hey I get it, it's just that safety as in size and mass is significant when driving next to semi trucks and delivery vehicles.

In the case of a 70,000 lb fully-loaded semi truck, it won't matter whether you're driving a 9,000 lb Hummer EV, a 1,900 lb Mitsubishi Mirage, or a 180 lb Electrathon race car. In either case, odds do not favor survivability for the occupants when up against something like this. You might as well get into an accident with a freight train.

1kWh only gets us about 1 mile at race pace with top tier electric sprint karts on short technical tracks. Of course we have a lot more mechanical loss due to a solid rear axle and scrubbing with wider and much stickier tires, with much shorter WOT / full brake "straights" that burn power. For 120 Mph on long tracks, the noted Tesla is even MUCH more efficient than our ~0.9 Cd karts where we then plument to about 2.5kWh per mile when not in draft.

So I guess you could say we are trying to use as much energy as quickly as possible (having a lot of fun along the way)... on a budget. Energy costs are the least of the overall costs, electric or otherwise. At least we don't have to rebuild the 2-stroke engine after every race.

Makes sense. You can easily use up 25x the energy racing on a per mile basis, than would be used cruising along at highway speeds. Unlike ICE cars, EVs have a broad peak efficiency band, whereas with an ICE, increasing load tends to increase thermal efficiency.

 

[ProEV]

Curious - where do you have the complete rules at?

1kWh isn't much, how many laps or time do you run for a race?

Here is a direct link to download the PDF version: https://www.electrathonamerica.org/_files/ugd/032d61_adf13ba2aa674698914f6caa4a78f49d.pdf

This is the current rule set. Same rules since 2019.

Tracks are different sizes and shapes, so number of laps would be confusing. The record distance for an hour is 62.1 Miles. It was done on a huge Tri-oval but it is still pretty amazing. Most races on tight parking lot tracks tend to be around 30 miles.

 

[ProEV]

1kWh only gets us about 1 mile at race pace with top tier electric sprint karts on short technical tracks. Of course we have a lot more mechanical loss due to a solid rear axle and scrubbing with wider and much stickier tires, ...

https://www.youtube.com/@ElectricImp

In the videos, the bar graphic on the bottom left is the change in Kinetic energy when compensated for energy being added by throttle. In other words, energy used overcoming rolling resistance, aero drag, etc. Even with a three wheel set up, we use more energy going through a corner. I can see this would be a lot more with two wheels connected with a solid rear axle. Sometimes the only way to get a Kart to turn well is to shorten the rear axle and allow the inner tire to lift.

 

[ProEV]

Here's pics of a prototype a friend of mine put together:

One thing that I was surprise to discover when I started racing Electrathon is how much I like using Lever Steering. If the leverage is correct, it is a very simple and surprisingly intuitive to use. I feel like I am almost thinking the vehicle to where I want it, which is something I always want with a race car. Your friend's design illustrates the complications that can be involved in putting in a steering wheel.

 

[The Toecutter]

One thing that I was surprise to discover when I started racing Electrathon is how much I like using Lever Steering. If the leverage is correct, it is a very simple and surprisingly intuitive to use. I feel like I am almost thinking the vehicle to where I want it, which is something I always want with a race car. Your friend's design illustrates the complications that can be involved in putting in a steering wheel.

It is a prototype mockup. We want to make a miniature rack and pinion with a collapsible column for my electric velomobile build, but it will be difficult to pull off since I need to have my brake levers located on the steering wheel and must keep it to where 180 degrees of position accounts for the entire vehicle's steering range, while leaving enough clearance for my legs while pedaling. Lever steering is MUCH easier to implement.

 

[CMo44]

I just discovered electrathon today while looking at velomobile & fairing ideas for a custom build. I'm curious if THIS could be altered slightly to use in what I want to build. Front axle & steering are the only parts of this build I'm not experienced with. I've built bikes, e-bikes from conversion kits, and can weld. $250 (plus $30 for shipping) is enticing to have that problem solved. But it says it's set up to run 14" wheels and geometry is based on 55" wheelbase. Also I can't tell from the pics if I'd be able to pedal without banging my knees on the steering assembly. I wish there were more pics and info such as weight.

I'm also wondering why the velomobile and electrathon builds are so different in the areas of wheel size and chain gauge? Seems all the electrathon builds are running smaller and thicker wheels with heavier duty chains vs the standard bicycle wheels and bicycle chains of velomobiles. I assumed they'd both want to reduce weight in those areas.