170mph EV Land Speed Motorcycle

[coleasterling]

For those of you not on the Facebook page, a team of guys including myself built a bike to go to the 2021 Bonneville Motorcycle Speed Trials this past week. We ended up going significantly faster than calculated, with absolutely fantastic salt conditions (best in years). We managed 12 total runs, with only one mechanical failure (broke a chain) and no electrical failures. Our slowest runs were the first two of the week, unfaired, at 140mph. We ended up the week with our fastest run at 167mph average across the mile and 172.7mph peak. We should end up with a certified national record just under 167mph.

The records in our class, which is AMA sub 150kg A and APS-Electric, were previously 114mph and 113mph, respectively. While we didn't register for the FIM class, those equivalent-class records were each ~110mph, making our motorcycle, unofficially, the fastest electric motorcycle in the world under 150kg. Pretty cool!

[Jordan325ic]

That is a gorgeous bike! Without giving anything away, what are the rough specs??

[coleasterling]

That is a gorgeous bike! Without giving anything away, what are the rough specs??

We're happy to give most of it away, actually! We're using an off-the-shelf HPEV's drive system since that's what we had laying around. This is about as budget an effort as you can get. I, quite literally, had the entire drive system already around the shop. We just had to buy a second set of batteries for the second box, 2nd isolation monitor, plus wire, cable, lugs, and fiddly bits, plus supplies for the fairings.

The motor is an AC31 from a Miles ZX40. The 2800ish RPM torque knee was perfect so that we didn't have to have custom gears made. The controller is an original Curtis 1238-7501 from an electric Jeep project I parted years ago. Both are well over a decade old, I think. Batteries are HobbyKing 6S 5Ah, 50C cells that we did extensive testing and matching on since we're running a series/parallel configuration. 30S/5P. Running EV200 contactors, Bender Isometer, a 5 ANT BMS stack(works great, BTW), and an Elcon PFC1500 charger.

Fairings are 3k, 6oz carbon, laid up from a CNC-cut master with 3 surface layers, then reinforcement added with both regular pink insulation foam and 1/8" Divinycell foam. They weigh about 17lbs and we've approximated the Cd at around 0.3. We're looking at data from the past week to try and get that a bit closer.

Rules say the bike has to weigh less than 150kg, so we made sure to weigh well under that and came in at about 317lbs with fairings on, then we added significant ballast to get to 326lbs, ish. It is counter-intuitive, but we want as much weight as possible to increase our available tractive force, since the friction coefficient can't be modified easily.

[ZeroEm]

Great job. Think it might be a while before someone beats you. Like that frame, looks nice and rigid? nothing wasted.

[coleasterling]

Thanks! I'm not so sure it won't be beaten fairly quickly. We've been saying from the start that someone could easily outspend us and do better. For a first time out, we're all very pleased!

[j bjork]

Very cool

A build tread would be nice
So the motor comes from a small, slow car?
Never heard of it before I think, but google knew of it..
Didn't find anything on the motor itself though.

The closest I get on the controller is the curtis 1238E-75XX
https://cdn.curtisinstruments.com/produ ... eet_en.pdf

What kind of power ore you feeding the motor?
You probably run it on a dyno to?

[coleasterling]

Very cool

A build tread would be nice

Thank you! Pretty much everything that's interesting is on Instagram, actually.

So the motor comes from a small, slow car?
Never heard of it before I think, but google knew of it..
Didn't find anything on the motor itself though.

Yep! It was an OEM motor for Miles. Torque knee is at around 2800RPM. You got it on the controller. It is 130V absolute peak, 550A RMS.

[Frank]

Did you guys monitor motor temperature during the run? How long did one run take?

I'm wondering if a newer HPEVS AC-23 might work in a roadrace type application and am worried about overheating. Any thoughts on this?

[coleasterling]

Did you guys monitor motor temperature during the run? How long did one run take?

I'm wondering if a newer HPEVS AC-23 might work in a roadrace type application and am worried about overheating. Any thoughts on this?

Yessir, we did. Peak motor temp was 114C on our 5 mile course attempt, which was about a minute and 20 seconds long. Running the 3 mile course, we never broke 85C. Keep in mind we were running very low RPM's since we have an AC31 and geared to make peak power at the end of the first mile...Averaged about 3800rpm. The fan can do a lot more cooling than that if you're willing to go into field weakening. The other, higher rpm motors will do better there, too.

That said, once heat soaked, the heat does not come out quickly. I'm not sure any of the HPEV's motors would be suitable for a road race application.

[liveforphysics]

Kudos and congratulations to your huge success!!

It would be interesting to see how a Zero SR-F with alternate gearing and the big heavy pack replaced with a tiny hobby RC pouch pack to make the weight limit would do on the salt.

[coleasterling]

Kudos and congratulations to your huge success!!

It would be interesting to see how a Zero SR-F with alternate gearing and the big heavy pack replaced with a tiny hobby RC pouch pack to make the weight limit would do on the salt.

Thanks sir!

I'm not sure about a stock chassis SR-F, but an SR-F drive system in our bike with our CdA, assuming it could do peak current for a true 80-85s, would be kissing 200. Really, really, close. We're around a 0.29Cd, which is what our CFD predicted, but we had assumed there's just no way that would be close. Turns out it was pretty dang close, haha.

If it could meet weight, I would think the SR-F could stomp our unfaired record. Not sure about faired. Proabably not without some significant aero mods. You could always just run the heavier class. AMA and FIM rules are merging in 2023, so you'd get stuck competing against the Voxan. Might not be very fun knowing you have no chance of getting the record.

Speaking of going over 200, you have any ideas for an 85lb motor and inverter package that can do 150kW? I contacted Integral and Equipmake and they both have suitable packages, but our fundraising efforts would have to be...substantial. Running big power in the 300kg class is so much easier!

[Frank]

Did you look at any Emrax offerings?

[coleasterling]

Ya, the 268 can't do it and the 348 is too heavy. We'd need to run the MV version of the 268, but we're limited to 500V. Driving the LV version is difficult because of the low inductance...not many inverters out there that'll do it well for a traction application.

[Frank]

Parker GVM210-150 will do the trick but that would be a heavier package. Not by that much though.
FWIW Cascadia now has a new inverter (new to me anyway) CM200 that's lighter, tons of amps and greater voltage range.

[DogDipstick]

That was cool. Congrats. I wish I got to do that kind of stuff.

Lol @ Hobbyking batteries. Lol @ 5p, 30s, Hk lipos. Really? Thats all? I got 4x that many watt hours in my garage right now ... In much lowr IR albeit larger new cheaper Chevy cells.

4p, HK lipos, @ 5Ah = about the same IR for a 2p of Chevy cell.. So I guess you were a little lower than that. .... but half the mass around the 180wH/kG mark. Half capacity too. You would need 50Ah of Volt cells to get that low. Mass increase would be about 30 lbs.

I cannot wait until we see good motors in the junkpiles. Then maybe. I just dont see them.

[coleasterling]

Parker GVM210-150 will do the trick but that would be a heavier package. Not by that much though.
FWIW Cascadia now has a new inverter (new to me anyway) CM200 that's lighter, tons of amps and greater voltage range.

Too heavy, sadly. We need to add more battery, so the drive system needs to gain power AND be lighter.

That was cool. Congrats. I wish I got to do that kind of stuff.

Lol @ Hobbyking batteries. Lol @ 5p, 30s, Hk lipos. Really? Thats all? I got 4x that many watt hours in my garage right now ... In much lowr IR albeit larger new cheaper Chevy cells.

4p, HK lipos, @ 5Ah = about the same IR for a 2p of Chevy cell.. So I guess you were a little lower than that. .... but half the mass around the 180wH/kG mark. Half capacity too. You would need 50Ah of Volt cells to get that low. Mass increase would be about 30 lbs.

I cannot wait until we see good motors in the junkpiles. Then maybe. I just dont see them.

At the speed we were ran, you don't really need much energy. These were a third of the price of Lonestar EV cells. I've been through every salvage cell you can think of and none are really suitable for the application. 30lbs means we're overweight and don't pass tech. kW/kg is pretty much the most important spec. The faster you go in the mile, for a given power, the less energy you use. Our fastest run overall used the least energy. Energy-wise we could have made the run on well under 10Ah.

[DogDipstick]

Our fastest run overall used the least energy. Energy-wise we could have made the run on well under 10Ah.

Coolio. How... much did you weigh in at, and... how much weight is " too much to pass tech?"...

How much does she weigh? I cannot believe you use those ANT bms thingies, you should get the ones non distributed with the 300A HV solonoidds and the inch thick shunts. Lol. I have been selling them. No complaints. Ant has high resistance in comparison.

[coleasterling]

Our fastest run overall used the least energy. Energy-wise we could have made the run on well under 10Ah.

Coolio. How... much did you weigh in at, and... how much weight is " too much to pass tech?"...

How much does she weigh? I cannot believe you use those ANT bms thingies, you should get the ones non distributed with the 300A HV solonoidds and the inch thick shunts. Lol. I have been selling them. No complaints. Ant has high resistance in comparison.

Read the first couple posts, it's in there. Check teamspeedhertz instagram for more battery info. We didn't run the high-current path through the BMS stack.

[DogDipstick]

Read the first couple posts,

Lol I read that four times and didnt get it until the 5th. Me and my lack of reading comprehension. Srry bout that.

Lol. Ty. Bike looks like its 150 lb not 150 kilo. Cool. Again.

[coleasterling]

She's pretty beefy! The frame is overbuilt, but was left over from a previous attempt (gasoline) that never materialized. Chassis without drive system is over 120lbs alone! I think we can easily get 15lbs out of it.

[Hillhater]

But i thought you needed the weight for traction ?

[coleasterling]

But i thought you needed the weight for traction ?

Yep, we'd put it right back in, in upgraded drive system and battery weight.

[DogDipstick]

What is a Bender "Isometer", and why do you need one?
Is it a racing requirement? Is it just so you dont take the chance, and blow up your expensive stuff (motor, controller inverter bank)?

Lol. Sorry for such a novice question,. What does it do? How come you need one? Is it really dangerous, 126Vmax (30s)? What does it protect?

[coleasterling]

The Bender just measures isolation between the HV and LV system. It wasn't rules-required, but is relatively cheap and super easy to use, and is a good practice anyway. 126VDC is fairly safe, but we're also on salt and didn't know if it was going to be dry or wet. It would open our contactors and alert a fault if it detected any HV leakage, hopefully killing the fault condition and preventing the rider from being shocked.

[coleasterling]

Cool little article from Texas A&M about our effort:

https://engineering.tamu.edu/news/2022/ ... OedWSo1imY