Forum Project - Electric D2?

[tintin]

I'd start by talking to Richard Morgan or Graham Swann - oh wait, I already have!*1 from http://www.electricclassiccars.co.uk/ 'cos they're good at this.

Seriously though, I only talked to Graham about this for about 15 minutes, but be gave me (me!) confidence that this is eminently doable, whether using Lead/Acid or Li/Ion (from memory, he's used the latter).

He's really approachable, and is doing this because he wants to, not because he wants to build a massive profitable conversion business, so I'm sure he'd be pretty open with his advice.

One of the really beauties of EV propulsion is it's simplicity - it must be easier than some of the projects attempted on here!

I'd be happy to pick up the 'phone to him, if that helps you Goran.

*1 at this in September:

https://www.eventbrite.co.uk/e/elect...s-24715554890#

[YorkshireBloke]

£50 of Yorkshire money if you make progress on this...

That is the same as £1000 of Down Sahhth money.

Robert

[MikkiJayne]

Wheeler Dealers spent $20K on their Maserati from memory, and couldn't even be bothered to sort out the suspension so it ended up dragging its arse on the floor. They could easily have put all the batteries in the front with a bit more thought on the layout.

I did note that they went for a brushless AC motor though, for better performance and less maintenance. Do Tesla drivetrains come up for sale much? I think a D2 would need a Leaf motor on each wheel to still move

It occurs to me that a 2.8q or even 3.7q (sorry Sergei and Neil) would make a great donor for a petrol-electric plug-in hybrid (like a Fisker). If you put the motor where the rear diff is, LiIon batteries where the fuel tank is, and a 1.2 3-cyl engine up front as a generator (along with a few more batteries) you could end up with adequate performance and massive range. Replacing 500Kg of drivetrain gives you quite a lot of potential for things to put in its place

You probably would need bottomless pockets though

[Goran]

Thanks Steven for the reccomendation their site looks very professional.
Rather than a personal project, I was hoping for this to be more of a forum project, for whoever is interested, to bring together forum skills and so we all learn something. A bit of electronics, engineering, design, machining, etc.

The finished car could then be donated to A8parts as a demo car for the forum and for A8parts, and to show off how versatile a D2 platform is.
The ideal of course would be to have a two motor set up one driving the front axle one driving the rear axle to stay true to Audi's design. But to start with Mikki's idea is best just to go with FWD or RWD for simplicity. They spent $20k on the Maserati! that's nuts, I'll have to watch that episode.

I think weight wise it may be ok. Nissan leaf weighs around 1535kg. A rought back of the cigarette packet calculation for a D2

1730kg for a manual S8 so to get down to the bare platform:
1730
-198 engine
-85 gearbox + flywheel
-66 fuel
-10? fuel tank
-10? front shafts
-10 prop shaft
-11? various other engine bay parts
1340 chassis

+218 Nissan battery equivalent
+58 Nissan leaf motor (not clear if Power module is included)
+23? other random stuff to mount battery and motor
1630kg total

So it seems it would only be 100kg heavier than a standard Leaf. Should be able to move along

There are a few Leafs being broken on UK ebay already, if this project got serious I would be happy to buy a Nissan Leaf motor + power module for around £1300 and donate it to the project. It would probably be easiest to fit it in the engine bay to drive the front wheels and just adapt half shafts to fit the D2 drive shafts.

http://www.ebay.co.uk/itm/2014-Nissa...UAAOSwI2xX8l2y

Alternatively, we could get creative and look for other cheaper solutions such as motors from the various Renault electric cars, Kangoo, Zoe, etc. Or even build our own control module.

Battery cost would be the major hurdle.

I know its all a bit pie-in-the-sky thinking, it would be cool to see a electric D2 though. Or a D3 for that matter (only if we could get rid of the complex air suspension ). To me it seems the lighter weight of aluminium platforms is well suited to electric powertrains.

[MikkiJayne]

The 2.8 FWD 5-speed with velour interior barely tips the scales at 1500Kg Its a passenger heavier than our TT!

Why do most conversions hook the motor up to the original gearbox (as WD did)? I would have thought direct drive to the diffs would make more sense, like the Leaf unit appears to do. With a motor having max torque from 0 rpm it seems like a gearbox is pointless.

Doing direct drive, you could easily put two motors in place of the gearbox, one driving the rear diff and one driving the front (use a rear diff flipped over). Then, all the power control and batteries go under the bonnet to keep the weight balance right. A pair of 150hp motors would push it along nicely

[MikkiJayne]

Interestingly, the Leaf has a single reduction gear of 7.9377. The motor has a top speed of 10,390 rpm, so with the D2's tyres that would give a top speed of 100mph which is probably adequate

I still think you'd need two of them to have acceptable performance in a D2 though, since 11 seconds to 60 is a bit embarrassing for a car like that. It'd be relatively simple to fit in the front, but a little tricker to put in the back unless you decouple the controller hardware on top from the drive system. You could probably just extend the cables and put that in the boot though. The subframe may need a chunk of work to fit the drive in it too, since it looks quite wide.



If you could use an aftermarket controller with it then it'd be relatively simple to tie both drives together, electrically.

Two of these are a little heavier than the 5HP24, but the fuel tank goes as does the propshaft and rear diff so I reckon that's about even, leaving a good 250Kg left for batteries. The Leaf battery is 300Kg, so thats not far off.

Range would be a bit pants - probably only 50-60 miles. It'd be a good commuting car though

[MikkiJayne]

And now I have this stuck in my head, so you lot can too

https://www.youtube.com/watch?v=MK1g5dMYR3s

[Goran]

Some great ideas there Mikki, keep em coming

Yes unfortunately the Leaf and Tesla motors need a single speed reduction gearbox, in order to attain motorway speeds. Interestingly both are roughly 8:1
There are exotic motors out there that have the torque at low rpm and high rpm capability that don't need a reduction gearbox at all, but I don't think they have made it into any cars yet.

Before I found out that Leaf and Tesla need 8:1 reduction gear, I thought about just using the D2 rear diff for front and back wheels and splining a motor directly into it. After all it is a bit like a reduction gearbox. If a more torquey motor can be found it could do alright with a 4.111:1 reduction?

Definitely two motors all the way. I don't know how it would work electronically though, do they need to be run from one controller so that traction can be controlled between front and back axles.

Great idea about space under the fuel tank, maybe a whole Leaf unit could fit under there if tilted at an angle?

Wow the Leaf unit is quite heavy with the trans included, that's around 80kg. With the control module its probably over 100kg?

Yeah! I'd rather have a D2 with 60 miles range than a Leaf!

[tintin]

Originally Posted by MikkiJayne

Interestingly, the Leaf has a single reduction gear of 7.9377. The motor has a top speed of 10,390 rpm, so with the D2's tyres that would give a top speed of 100mph which is probably adequate

I still think you'd need two of them to have acceptable performance in a D2 though, since 11 seconds to 60 is a bit embarrassing for a car like that. It'd be relatively simple to fit in the front, but a little tricker to put in the back unless you decouple the controller hardware on top from the drive system. You could probably just extend the cables and put that in the boot though. The subframe may need a chunk of work to fit the drive in it too, since it looks quite wide.



If you could use an aftermarket controller with it then it'd be relatively simple to tie both drives together, electrically.

Two of these are a little heavier than the 5HP24, but the fuel tank goes as does the propshaft and rear diff so I reckon that's about even, leaving a good 250Kg left for batteries. The Leaf battery is 300Kg, so thats not far off.

Range would be a bit pants - probably only 50-60 miles. It'd be a good commuting car though

That Leaf motor looks a bit bigger than the Tesla ones, I'll see if I can find some pictures.