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Electric motors (again!)
Slimy38 - 21/6/21 at 07:39 AM

I know it's come up a few times, and there's plenty of things to be worked out before it becomes a viable option for builders, but I was wondering one thing on the weekend. I understand that commercial cars have motors per wheel, but is this consistent? If a 7-type car was to be electrically driven, could it be put in the same place as a combustion engine and maintain the propshaft-diff-driveshaft-wheels drivetrain?


David Jenkins - 21/6/21 at 07:57 AM

This is the way that some car converters work - they use an adaptor plate between the electric motor and the bellhousing. They still use the clutch, but most of the time the car is left in 2nd or 3rd and driven like any other electric car, with no real need to change gear.

The big problem with the 7-style car is where to safely put the batteries...

EDIT: This company was featured in a TV series - quite entertaining, but their prices are scary!

Electric Classic Cars

[Edited on 21/6/21 by David Jenkins]


Russell - 21/6/21 at 08:10 AM

There are a number of smaller start-ups who convert older vehicles to electric, I'm sure you've seen them in the videos all over YouTube. One that caught my attention was a conversion of a Mk2 MX5, where the drive motor is a compact unit that fits in the transmission tunnel and uses a shortened prop to the standard diff etc. The batteries are nicely fitted in a cradle in the engine bay (effectively replacing the engine and ancillaries) and you can buy a bit of extra range by having additional batteries in the boot (but I used to own a MK1 MX5 and I know what the boot space is like!) Front-rear weight balance is apparently almost identical to the fossil fuel version and there's zero chopping of the chassis to make this work. Tidy!


Mr Whippy - 21/6/21 at 12:23 PM

There's quite a few vids on youtube detailing people builds using cheap cars such as Leaf's as complete donors. The Leaf for example like many uses a transverse layout identical to that of almost all cars. Plus the motor, inverter & charger can be broken down separately to best fit their new home. All of which are lightweight units that even on a 7 could be fitted into the back. Their only joined together by some cables and coolant hoses.

The battery is actually quite compact and built from what look like a pile of flat cans wired together. Nothing at all stopping anyone building their own battery box any shape they want to fit under a hood and many do. Nissan's own layout could certainly be improved upon like some spacers for better airflow. Two stacks of 20 modules which would be about the same physical size as an engine etc. Performance would be hilariously rapid, especially from a standstill.


Slimy38 - 21/6/21 at 12:32 PM

quote:
Originally posted by Russell
There are a number of smaller start-ups who convert older vehicles to electric, I'm sure you've seen them in the videos all over YouTube. One that caught my attention was a conversion of a Mk2 MX5, where the drive motor is a compact unit that fits in the transmission tunnel and uses a shortened prop to the standard diff etc. The batteries are nicely fitted in a cradle in the engine bay (effectively replacing the engine and ancillaries) and you can buy a bit of extra range by having additional batteries in the boot (but I used to own a MK1 MX5 and I know what the boot space is like!) Front-rear weight balance is apparently almost identical to the fossil fuel version and there's zero chopping of the chassis to make this work. Tidy!


Potentially this one?

https://www.youtube.com/watch?v=VZws7kE3U5k&ab_channel=TheLateBrakeShowTheLateBrakeShow

Looks like a decent set up, although that Hyper 9 motor they talk about has popped up on a few searches for me. That's a 4K block of metal to start with.


Russell - 21/6/21 at 02:38 PM

quote:
Originally posted by Slimy38
quote:
Originally posted by Russell
There are a number of smaller start-ups who convert older vehicles to electric, I'm sure you've seen them in the videos all over YouTube. One that caught my attention was a conversion of a Mk2 MX5, where the drive motor is a compact unit that fits in the transmission tunnel and uses a shortened prop to the standard diff etc. The batteries are nicely fitted in a cradle in the engine bay (effectively replacing the engine and ancillaries) and you can buy a bit of extra range by having additional batteries in the boot (but I used to own a MK1 MX5 and I know what the boot space is like!) Front-rear weight balance is apparently almost identical to the fossil fuel version and there's zero chopping of the chassis to make this work. Tidy!


Potentially this one?

https://www.youtube.com/watch?v=VZws7kE3U5k&ab_channel=TheLateBrakeShowTheLateBrakeShow

Looks like a decent set up, although that Hyper 9 motor they talk about has popped up on a few searches for me. That's a 4K block of metal to start with.


Yeah, that's the one. £4k for the motor! WOW! Mind you, have you seen the price of a Cosworth Pinto thingy or a sorted VX XE?


Simon - 21/6/21 at 04:03 PM

The two wheel drive Teslas have one motor through a diff


rf900rush - 21/6/21 at 09:44 PM

I recently saw an atrical using a mitsubishi phev rear diff which housed an electric motor.
Looks like a very neat option to DIY EV's.
The only bad bit, like most EV/Hibrid, is the Dangerously High voltages used.


Mr Whippy - 22/6/21 at 05:51 AM

Yeah the voltages definitely need to be respected but the training is there as is all the safety equipment. Its funny that we regard EV power trains as fearsomely dangerous but for a century saw nothing at all wrong with carrying large quantity's of extremely volatile petrol in flimsy metal or plastic tanks, I mean just look at were the tank is in a 7! Remember the Ford Pinto... I'm amazed the SVA lets us away with it tbh, although a good alternative location on a 7 is difficult.

I'm sure in 30 years people will look back in horror at those dangerous old fiery petrol cars people use to drive, they were crazy mad in those days...


James - 22/6/21 at 04:02 PM

quote:
Originally posted by Mr Whippy
Yeah the voltages definitely need to be respected but the training is there as is all the safety equipment. Its funny that we regard EV power trains as fearsomely dangerous but for a century saw nothing at all wrong with carrying large quantity's of extremely volatile petrol in flimsy metal or plastic tanks, I mean just look at were the tank is in a 7! Remember the Ford Pinto... I'm amazed the SVA lets us away with it tbh, although a good alternative location on a 7 is difficult.

I'm sure in 30 years people will look back in horror at those dangerous old fiery petrol cars people use to drive, they were crazy mad in those days...


Yes, the thought of a rear-ender (ahem!) in the Locost frightens me!


David Jenkins - 22/6/21 at 04:06 PM

It's one argument for having a spare wheel on the back - something extra to spread the impact.

As for batteries - watching the series I mentioned earlier, all the battery packs went into hefty steel boxes, so probably more impact-resistant than my ali fuel tank.


Mr Whippy - 23/6/21 at 07:17 AM

quote:
Originally posted by Slimy38
I know it's come up a few times, and there's plenty of things to be worked out before it becomes a viable option for builders, but I was wondering one thing on the weekend. I understand that commercial cars have motors per wheel, but is this consistent? If a 7-type car was to be electrically driven, could it be put in the same place as a combustion engine and maintain the propshaft-diff-driveshaft-wheels drivetrain?


Tbh I'm not sure motors per wheel are the norm at all, I'm struggling to think of any. Many DIY conversions do still use things like leaf motors connected to the gearbox via an adaptor plate and the conversions look super simple and cheap. Leaf's have been around for a decade, the motors will outlast the rest of the car and there are hundreds available on ebay etc for only a few hundred. Don't be fooled by the 110bhp rating on even the early cars, they just don't compare properly to petrol engines, as my leaf puts my 180bhp 2.0 petrol Volvo to shame. It's electronically limited to 99mph but I recon it could go to 120mph if they let it, just ditch the standard controller. I think a motor like that on a 7 would be a wild ride. If you put something like a Tesla motor on your just going to kill yourself

[Edited on 23/6/21 by Mr Whippy]


BenB - 23/6/21 at 07:31 AM

Suspect there might be lots of nice tesla motors available relatively soon given the life expectancy of the batteries and intermittent quality control on their car builds. As said you have to respect the voltages but then this is also true of chop saws, angle grinders, engine hoists etc etc.


scudderfish - 23/6/21 at 07:49 AM

Fun fact, 50 litres of petrol contains the same chemical energy as 400kg of TNT