Hybrid AWD conversion
 

I'm looking a little into doing a hybrid-conversion.
This isn't realy anything serious yet, but I was thinking a little about it.
My car has no engine or gearbox up front and just enough space below the "frunk" to add some driveshafts and a small electric motor or two.
The big question would be how to run driveshafts from the hubs to the motors as I don't think my front hubs are meant to have driveshafts.
On the other hand it isn't unlikely Toyota has used pre-existing hubs upfront or there might be compatible ones that could fit.
Besides, a little performance increase would undoubtly be fun and I've got an 11 kW outlet at home.

Go look up the Fiero hybrid on Youtube (assuming it's still there)...they basically chopped out the front crossmember and grafted in one from an EV or hybrid.

I would check if any hub from a Corolla or a Camry is suitable.

Often the existing knuckles will not accept hubs that accept driveshafts. I'll give an example:

In Honda circles, AWD conversions are highly desirable. Typically one uses an Element or CR-V transmission and rear differential. Turns out Honda Insight front hubs have the same axle size as CR-V or Element rear differentials, so you see tube frame fabrication for mounting points to put Insight knuckles and, sometimes, even control arms, into the back of Civics. The steering arm becomes a "toe arm".

Fronts are probably easier than rears, given that the MR2's front suspension almost certainly shares parts with some FWD vehicle you can steal knuckles out of.

My recommendation would be the rear axle from a Lexus LX400h or Toyota Highlander. Here's mine (on the right).

https://ecomodder.com/forum/member-f...mpare-size.jpg

It's a problem for me because the Toyota axle stubs are contrary to VW axles. But it wouldn't be for you. 68 hp, 98 pounds.

ecomodder.com/forum/showthread.php/hot-rodding-toyota-mgr

With 68 hp more, my little Spyder would get quite quick as well.
But I'll need to check if I can mount driveshafts to the hubs.
Also did some calculations on electric range:
As the Spyder has a pretty low CDA and low weight, I can get quite some range even from small batteries.
In case I'd go full EV, I'd be looking at over 300 km with a 30 kWh pack at 100 km/h.

Your little will become not so little... it is 98 pounds only for motor without battery and invertor.

And in electric drive, power more depends on the maximum battery output, not on the motor itself.

Would you mind some conversion from Prius2/Yaris/Aqua?

We're talking about the MR2 Spider?
My suggestion is to research and first see if anyone has done an AWD conversion before and then go with that. If not, you're going to be the first to do both the front drive line and EV aspect at the same time.

I know with the classic VW Beetles some had done 4WD conversions before. Using the same parts with the exception of modifying the transaxle adding the drive shaft, all you'd need more would be the electric motor connected to the new front differential and batteries and controller.

There are type 2 transporters with a drive shaft extending out the front of the trans to drive the front wheels. Other than being rare, I suspect this is easily adoptable even to modification of a standard transmission

https://www.thesamba.com/vw/classifi...um/6512756.jpg
https://www.thesamba.com/vw/classifi...php?id=1852996

This pile of Schwimmwagen parts sold for $8500.

I've seen where the original Beetle transmission was modified, a direct drive synchronizer from a completely different vehicle added to engage and disengage the front drive line, a differential, also from a random vehicle and Type 2 Bus rear hubs modified to become the front steering hubs on the modified 4WD Beetle.

seems you could use the trans axle from a AWD subaru. flip the R&P to get the direction you want

Definitely a possibility for an air-cooled VW (or one that's been converted to a Subaru engine as well).

However, the OP was asking about a Toyota MR2 Spyder. And the idea seems to be to leave the ICE and transmission alone and add an electric FWD system. Correct?

https://parts.mariettatoyota.com/ima.../a1_534207.jpg
parts.mariettatoyota.com/images/parts/toyotaOEM/fullsize/a1_534207.jpg

Hard for me to interpret this without an MR2 on hand, but it looks like 57301A and 57308 would be the part to modify.

Yes, basicly 2 fully independent drivetrains.

I genuinly can't tell wich part is what from that pic.

That was my comment as well, and you're the one with the MR2!

It helps of you know the conventions for exploded diagrams. 53701 and 53702 are [likely] the Macpherson strut towers. There is a 'firewall' to the right, and radiator and front bumper group to the left.

What is there at the center of the front axle line?

Fitting all the electric components in an MR2 that still has the gas engine will be very difficult. The electric motor and inverter will need liquid cooling. Depending on the battery that may need liquid cooling as well. Onboard charger will be liquid cooled if you want to get close to the 11kW charge rate but even a 3.3kw charger needs cooling air flow. Probably want a junction box for the HV contactors. Also not sure how much controller support you’ll find for the Lexus MGR since it’s not common for EV conversions.

IIRC there was a conversion kit aimed at the adaptation of a Subaru transaxle into Vanagons, but it was only available for that dual-range 5-speed manual.

cRiPpLe_rOoStEr -- Permalink #13.

Should be biking -- Everything you describe is needed for any electric installation, hybrid or pure EV. At Permalink #5 I pointed to the thread on installing the Toyota MGR. I don't think anyone has succeeded, at least with MPaulHolmes' Open Revolt controller. I wanted a pure EV install in my Beetle, but it is as you describe.

The easier option would be an GM E-assist altermotor installed on the MR2 ICE replacing the alternator and starter. ecomodder.com/forum/showthread.php/controller-mods-build-e-assist-altermotor. You can get by on 72-115V, much less expensive and dangerous.

But the ask is for four-wheel drive.

buy a RWD suv then convert it


the E assist is interesting wouldn't applying an external power screw with the ignition timing ?? also what if the transmission was not married to the engine speed... i.e cvt


i'm interested in the E assist.. so i could run it a cruising speed my has auto stop below 30mph... this presents an issue

That wouldn't allow me to drive without the ICE engaged, wich would be significantly less efficient.
The main reason for hybridisation is to run purely electric whenever possible.
Also there isn't any space for a larger alternator in the engine bay of the MR2 Spyder.
The alternator is cramped between cylinder head, block, intake, firewall and part of the roof.

Another idea would be to go "all EV" but add a small ICE as a range extender.

The problem is finding a small water cooled engine that provides enough power. Of course if you drive down the Autobahn you'll need more power to keep your speed up. Maybe a modified outboard motor off a boat.

Another problem is small ICE to generator to motor efficiency will likely get you worse gas mileage.

That's a different transmission, 2WD only and no dual-range.

I think I figured out that a proper voltage reconfigured genset of 6hp was enough wattage capacity to drive my Ranger at street speeds up to 40mph. A dual cylinder 25 hp genset should do enough watts to drive pretty much everything else modern

25 hp would be sufficient for 135 km/h in case of my car, but IMHO it would be easier to just have a seperate electric drivetrain for shorter trips as well as using it in combination with the ICE for longer trips in what would essentialy be a very stretched out pulse&glide strategy.

One idea I had once was to bolt a sprocket to each of the CV axle flanges coming out of the transaxle and to hook up two small electric motors, one to each chain drive to each sprocket. Is finding the room to do that that's the hard part. Also the motors would be always connected, which would not be ideal for long distance cruising but would double as a hybrid system if it has regenerative braking.

Yea, that's usualy not a bad idea, but in my case the motor would be wedged between the engine and the exaust header with little airflow.
That's a little hot for an electric motor...

Water cooled motor?

If you're doing all that, a larger motor in the drive train would be better

That doesn't make it all wheel drive.

Would in an awd vehicle

Through-the-road electric/gas hybrid with a serial hybrid altermotor on the ICE. Done.

You reminded me of my early teenage years, when I was quite favorable to fit a motorcycle engine into a small car, such as a Honda CBF 250 engine into some Volkswagen-based beach buggy.