Wildly ignorant choice. No one's going to sell a big enough battery without at least modeling its effect on crashworthiness, which is expensive. No, you can't run the car without the engine running; you won't have oil flow in the transmission, power steering, or power brakes. The car will handle like shit with so much unsprung weight (which is why no commercial car has ever used them, just demos). And the price quoted is basically COGS!
Nobody on this process must have ever been involved in DFM.
That doesn't solve lack of lubrication to the transmission. Go read your owner's manual under the section regarding towing. There are almost always restrictions on maximum speed and distance with the drive wheels not lifted.
As the other commenter pointed out, there's a lot of hand-waiving going on by the kid who won the contest; it's like the farside comic where there's a giant "magic happens" in the middle of a board full of mathematic scribbling.
For example: running HVDC to the engine compartment (for the AC, power steering, and vacuum pump) from the spare tire well in a vehicle whose undercarriage isn't designed for it requires pretty substantial armoring.
The other problem: in-wheel motors are not new (Mistubishi sunk a LOT of R&D into it), and they haven't taken off for a reason.
They massively increase unsprung weight. Your average car wheel weighs maybe 30-40lb at most. He's probably doubling that. That means atrocious ride quality and traction issues, because the tire's going to be bouncing around like crazy due to the suspension not being designed to dampen that much weight.
The motor is also subject to all the vibration normally soaked by the suspension and vehicle frame. Trying to get an electric motor to withstand that sort of vibration is not a trivial problem.
This is just a bunch of hogwash from Dyson. The kid figured out that what they care about is a nice big fat PR grabber, and he gave them one.
It's not possible for a reasonable price. NRE costs per model would be high, making a farce of "Make your car electric for 5k".
For the mechanic installing the device, you have to have an installation manual listing where every cable and hose needs to go and be secured. And you need to choose well, because if it rubs anywhere: recall and fix (is there enough money in $5k for recalls? No).
You have to hack the ECM, /per model/, to allow you to drive without the engine actually running.
You don’t need a transmission if you have hub motors. It’ll be sat on the garage floor, so it would be a great surprise if it was running.
I’m planning on doing something similar on my old hilux. The lack of power steering or power breaks or any auxiliary system that relies on the engine simplifies the build substantially.
While using the gasoline engine, the power accessories (power steering, power brake assist, ABS!) are functional, but when the gas engine is powered off, you'll have none of them? That's going to get someone killed. And on top of that, the climate control issues -- A/C won't work, and the heat will only last so long as the gas engine is preheated and then only briefly as the coolant isn't being circulated.
The concept of hybrid is an invisible marriage of gas/electric propulsion brought to us by Toyota who perfected it in the Prius. This is just a hack as far as I am concerned. I would be more impressed if the engine were removed entirely, and this motor were bolted up to the transmission as a replacement flywheel.
You still reduce fuel use, don't need to change any other parts to work without the engine.
You just basically need to know when the accelerator and break (and perhaps clutch?) Were pressed, and perhaps change accelerator response to make it feel more natural.
I'm totally ignorant on this subject, but what if you just had the vehicle engine on and idling the whole time you were driving? That way it could power the climate control, power steering, etc., but presumably use much, much less fuel than if you were using it to accelerate.
The millions of existing ICE vehicles can be retained by the people who own cars but use them rarely, and new EVs can be used by people who need to drive significant distances.
That's always been my thought as well. Why can't I just have some rechargeable component that significantly boosts my gas mileage for the typical 30-40 mile daily drive. The occasional 200-300 mile long distance trip I'm fine with using gas purely.
I would certainly consider it for 10k. Because no I wouldn't buy a Prius because they look goofy and I like my current vehicle. 10k is close to the tipping point, but would probably be worth it. If it was cheaper though definitely.
The ford f150 was popular for conversion kits from multiple companies. One of the easiest platforms to convert, lots of room for batteries and engine swap. Google and you can find multiple companies offering a swap.
Also ford going to offer a conversion kits with Mach-E crate motors, but appears the supply shortage and rising prices put a pause on it.
I'm not sure how "available" it is in the real world, and I'd note that it is sold through authorized installation centers rather than direct-to-DIYer.
That's more practical than wheel motors. Also, with pickups, there's room under the bed for the battery.
Ford has a new electric truck platform in development, the "T3". This is supposedly electric from the ground up, unlike the F-150 and Ford Transit, which are modified versions of gas vehicles.
I am always skeptic when I read about work on a car and “less than a day”. Trailer hitch install with cabling took exactly 4 hours. Dash cam install took 3 hours. Both on rather small bmw 3 series car. Doing cabling properly is always pita. Be it a house or a car. There was a newspaper article wringing, that battery replacement alone for Kia ev6 takes whole day.
Very interesting concept. Looks like the motor might be very lightweight so hopefully doesn’t add too much unsprung weight to the wheels. Wonder if it can be made to be durable under those conditions though.
Cost: I’d assume the cost is for a single motor; that would be a fairly unstable vehicle to drive with different left/right turning behavior.
Wheel offset: Mounting the motor here will require a pretty massive increase in wheel offset or a pretty massive outward push of the wheel centerline, with each having its issues.
Brake heat: If the stock brakes are used they will likely cook themselves and the motor. You are essentially requiring the electric motor to do all the braking, or else developing a hybrid braking system. Using hydraulic brakes on just one axle is a non-starter for safety reasons.
Very clever idea, and maybe they can make it work. There are more than the reasons I listed as to why this hasn’t been pursued previously.
No; brakes function by turning the kinetic energy of the vehicle into heat via friction; using the motors for braking via regeneration produces some heat, but a fraction of the amount.
For reference, it’s not uncommon to see temperatures of 1000F or higher after a single highway speed stop on the front rotors of most passenger vehicles. Having that amount of heat that close to the motor is something that needs to be designed around. The rear brakes will typically be 200-400F cooler depending on the weight bias, but that’s still not a trivial amount of heat.
a) An ICE car is going 60 mph and brakes to a standstill.
b) An electric car is going 60 mph and brakes to a standstill.
How does one generate more heat than the other?
Why would the brakes "cook themselves" in b when they don't in a?
>For reference, it’s not uncommon to see temperatures of 1000F or higher after a single highway speed stop on the front rotors of most passenger vehicles.
I'd like to see that reference. 1000F is F1 tier, lol.
Because in this proposed design the motor is the brake rotor, they're the same part. So when you apply the brakes, they get hot, so does the motor. Motors getting hot is not good.
Electric cars have regenerative braking and also regular brakes.
Regenerative braking doesn't replace the need for brakes. There are lots of reasons why, safety reasons, that you need thr brakes to work even if power fails, when the car is parked etc.
At certain times. At other times the regenerative braking isn't even operating. So unfortunately it doesn't do much good because you still need to design the brakes to cover what's needed during those tines when regenerative braking isn't helping.
[EDIT: Mea Culpa - he did modify the rear wheels only in the prototype]
Actually, I think it is perfectly practical for a DIYer like me, with the following small caveats (as opposed to your large caveats):
1. Use a front-wheel-drive car as the donor.
2. Mount two motors on the rear wheels (one per wheel).
This way:
1. The first instability from torque steer due to driving only a single wheel is gone - car will accelerate in a straight line because equal power is provided to both wheels. The second instability from larger unsprung mass is easier to mitigate on non-steering wheels (i.e. the rear wheels). The third instability from increased wheel offset relative to the kingpin is completely removed.
2. Modifying the offsets on the rear axles (specifically, reducing them) in a FWD car is simpler[1] than doing the same on the drive wheels. If a double-wishbone design is used, it becomes a little complicated, but no more complicated than doing the same on the front.
3. The rear wheels do (IIRC) ~10% of the braking work that the front wheels do, so there is less heat generated. Until recently, quite a lot of the low end cars came with drum brakes on the rear anyway/
I'm curious why he placed the prototype on the front wheels - he must have had a good reason. After al;, someone who came up with the design itself isn't stupid, and someone who actually modded the car knew what they were doing as well, so there's probably a good reason for modifying the front wheels and not the rear.
[1] Still complicated, but a lot simpler - because the wheels don't steer there is no need to worry about the steering geometry, track rods/steering rack modifications, etc.
But the rear wheels in a FWD are rarely designed to push the whole car. They are designed to hold the car off the ground, so 10% of braking, and that’s about it. Once you want to apply torque to them, they either fold under the car, or you just bend whatever is holding them there.
I’m assuming one motor at the lowest price point that the site is quoting, and because they state they only have one motor made now. That implies they are comfortable with the trade off and they see two or four as optional.
I’d love to see an electric three wheeler, maybe like the old heavy duty Mazda trucks!
Still wish someone would make a fairly straightforward retrofit that would “battery-ify” the electric loads on a vehicle. Would maybe handle 5-10% of a vehicle’s load, but should be the most straightforward to install.
Some newer vehicles have a “belt-starter-generator” that’s just on the accessory belt, like the Fiat 500, and a tiny <1kwh battery, but dunno why it’s not expandable or why nobody makes something bolt-on for ICE vehicles that are common. Companies make a bolt-on supercharger kit for the Corolla, but nothing like this that could be useful in fleet/delivery/taxi applications.
I guess gas is too cheap to plug in one’s vehicle for a 10% reduction in fuel consumption.
BMW has been doing this as standard for 10+ years. They call it efficient dynamics.
Basically a lot of the extra things like power steering and water pump are electric instead of engine driven. And the generator is set to run as much as possible only when decelerating / braking. So it's using energy that would normally go to waste in a non-hybrid car. The battery is 1kwh which is enough for this purpose.
They haven't incuded the air conditioning pump in this, probably because it requires more power than the electrical system on a non-hybrid car could handle.
Honda had the electric engine essentially replacing the flywheel on their IMA system. They could have dropped the typical starter motor but it was kept for redundancy.
While the ICE would still move at all times valves could stay up for 1 (only 3 firing) to 4 cylinders (no ignition at all) to eliminate pump loss (there's still friction loss). Sadly the electric engine is a bit weak for full EV operation except coasting but I found the approach quite elegant.
Not that it's valuable to compare napkin calculations but based upon my experience trying to save %'s in my decade driving EV's, I think at highway speeds it's closer to 1% than 10%.
You save considerably more energy by slowing down 10mph than you do by turning off the AC.
I don't think the electrical system load on the engine would amount to much gas saving, a 100 amp alternator may use only 4HP of your engine's power. Outside of the starter motor you don't use anything close to 100A for the accessories. Even an electric A/C is only a 5-10 horsepower saving.
You'd see a performance improvement by reducing those parasitic loads, but that doesn't translate into a 10% fuel savings.
ICEs are incredibly inefficient, most of the petrol energy is lost to waste heat. Something like 60+% IIRC.
On my MX-5 when I ditched the AC compressor and switched to an OEM manual rack the car picked up some pep but I observed no significant difference in MPG...
IIRC the major way to move the MPG needle on these things is to increase the compression ratio, since that's directly linked to the thermal efficiency.
It's not so much that ICE engines are inefficient, it is all heat engines of any type are bounded in by the same thermal limitations (ICE, gas turbine, steam turbine, other externally heated piston engines, etc). In the physics of heat engines, there is the Carnot efficiency that is based only on the temperature of the hot source (combustion chamber in an ICE), and the cold sink (atmospheric air). Relative to this limit on all heat engines, modern ICE engines are very efficient at their peak efficiency point.
A problem specific to ICE in a vehicle application is that at the engines end up running in conditions away from their peak efficiency point due to vehicle load, terrain and traffic conditions. That is where hybrids are supposed to pick up their efficiency by letting the ICE turn off completely in the regimes that force the engine to run at low efficiency points. Such as idling where the MPG is zero.
It's not 10% all the time. It's 10% with high beams on and every conceivable thing on max. Even then you'd probably have to have a super awesome stereo :D
ICE vehicles produce a large amount of emissions... but the ones that do no not use roads are the ones that generate most of the pollution, not the ones on the roads.
Off the roads there is less regulation and that is where 90% of the pollution happens.
That's complete BS. Off-road stuff can't possibly contribute to 90% of pollution even if everyone had a V8 off-road buggy and used it every weekend. It is waaaaaaaay less than 1%.
Almost nobody uses two strokes off-road. Like it's not even relevant to the discussion at all. Two strokes are almost completely gone in the western world save leaf blowers. Outboards have been largely 4 stroke for decades. Motorcycles - a very very small number of performance oriented bikes are two stroke, at least in the west. Motorcross people still use them but that's such a small number. In other places they are being phased out too.
The problem is when people say "off road" in this derogatory way it makes it sound like hobbyists like me are the issue. We're not. It's industry - large shipping boats are a huge contributor.
I think you are ignoring CO2 emissions. Off road vehicles produce a large amount of pollution (particulate , etc) but are a smaller contributor when it comes to greenhouse gas.
Heck, just leave the old ac compressor and heater in and run it off the idling ice motor intermittently. 1 gallon of gas would probably be enough to get you as far as a full battery charge would for a hot summer road trip.
Some unusually cranky replies in the comments. What is it about this project that gets commenters so lathered up? For context:
> The James Dyson Award supports budding design engineers at the start of their careers. If you’re a current student or recent graduate with an idea that solves a problem, we want to hear about it. We’ll be equally impressed by rough-and-ready prototypes as we will by mass market-ready samples.
A little off topic, but due to economics of scale, will the price of cars start to plummet once nearly everything is electrified ?
$5k seems cheap, even for a retrofit, I can imagine building a new car should be even cheaper than this. Of course there is the body of the car, interior and suspension, but the whole package together should become cheap as motors and batteries become ubiquitous ?
Batteries won't be cheap any time soon. It's totally possible to build a $5K car today. But it wouldn't meet safety or emissions requirements in most developed countries.
I mean, you're looking at up to 151$/kWH wholesale for the batteries. I'm assuming that doesn't include the cost of containers, wiring between them, logic or extra bits for the pack (e.x. IIRC Ford packs auto discharge in the cold to prevent freezing), or the cost of assembly.
That was exactly what I was thinking. How do certify _any_ electric conversion in a country with mandatory annual or biannual technical inspection (i. e. most of EU)? I remember reading somewhere that costs in Germany and/or Scandinavia are so high that whole endeavour is not worth it.
I would imagine a battery replacement would be more cost effective than swapping to a brand new drive system. The $5k estimate appears to be completely hypothetical, presumably based on bill of materials alone.
Nobody on this process must have ever been involved in DFM.