VW Golf Mk2 Owners Club

Possible Conversion Project??

April 13, 2022, 10:10:33 PM

I've had an idea...

While I'm interested in the idea of EV conversion, I don't want to blindly experiment on my beloved, though still tatty, 1990 Driver (183,000 miles for its 32 years), owned since 2008.

However, I might be interested in acquiring another Golf 2 (ideally as close to my Driver as possible to allow for future possibilities) with defunct engine or engine/gearbox combination.  There are a couple of possibilities for EV conversion:

1) A promising one is the replacement of the Golf engine and gearbox with a Toyota Prius Gen 3 Transaxle.   This would likely take up less space than the original engine/gearbox combination and all its accessories, leaving some space for a modified inverter and a supplementary battery pack (another pack would be needed in the rear).  Modifications/fabrications would need to be made to adapt the  transaxle to the original engine/gearbox mounts, and to provide for the installation of the inverter, auxiliary electronics and front battery pack, and to adapt driveshafts.  As more and more such transmissions (around £200) and inverters (around £150) come onto the secondhand market, this is the kind of project on which current research in the EV-DIY community is really focussing.  There is by now quite a mature body of knowledge in how to adapt inverters to control almost any AC motor (the Toyota transaxles have two motors, MG1 and MG2), and replacement logic boards are readily available.  Intense opensource research has been going on at OpenInverter.

2) A simpler, and older, possibility is the mating of a suitable AC motor to the existing gearbox (either retaining the clutch or not) using a custom adapter plate and coupler.  This is possible for transverse front wheel drive vehicles like the Golf, and for rear wheel drive vehicles such as the BMWs Damien McGuire seems to specialise in.  Here's Damien making such a modification (from about 9 mins in).  This possibility looks like it would allow for more space in the engine bay for the other necessary components.  Here's another example of Damien fitting a similar combination to a rear wheel drive BMW.  Again, a modified inverter is used to control the motor and other functions.

I find these interesting and exciting ideas, but I do have a few issues:  I don't have a garage or suitable workspace for a temporarily undriveable vehicle to sit for a considerable amount of time while an intensive learning process takes place.  I don't have any welding experience at all, and extremely rudimentary car mechanic skills (I'd be more confident with bicycles!).  In short, a project like this would necessitate my teaming up with others.  I don't even know how I would go about sourcing a suitable donor vehicle, or rather project vehicle - perhaps you have a suitable Golf sitting in your spacious garage that you were thinking of breaking for spares or just getting rid of...   I split my week between Slough and Bristol, so would be interested in exploring possibilities in either of those areas.

I'd be very grateful for any ideas and suggestions, and I'm particularly mindful that the very idea of converting a Golf to EV is total sacrilege to many owners!  I don't want to offend any sensibilities here, and I'm grateful to @Eddypeck for creating this section of the forum.

Re: Possible Conversion Project??

Reply #1 – April 14, 2022, 09:50:20 AM

I was going to reply here, but then thought my comments were kind of a separate topic in their own right so I started a new thread: https://www.vwgolfmk2.co.uk/clubforum/index.php?topic=1401.0

My own thoughts on an EV conversion are still around using a simpler vehicle, such as a Beetle, Fiat 126, Hillman Imp type of car. Not so much Beetles but the latter have had modders fitting high powered motorbike engines for years.

There's also the renovation to consider, I wouldn't want to drop an EV motor into a rot box, you'd want a fully sorted shell so picking up a project car you could be looking at £10k+ in welding, panels, paint and parts before you even look the conversion. I'm sure @Monkey with his Red Rescue https://www.vwgolfmk2.co.uk/clubforum/index.php?topic=695.0 would have an idea of what his spend has been so far, although I'm sure he doesn't want to think about it :wink:

Re: Possible Conversion Project??

Reply #2 – April 15, 2022, 09:40:30 PM

Wonderful work by @Monkey there!  That's very sure-footed and methodical, carried out by someone who thoroughly knows his Golf 2s!

In contrast, the work of many on the openinverter.org forum is very experimental and trial-and-error.  Here's one that's experimenting with Golf 2 and Prius Gen 3.

This illustrates the kind of idea outlined under example 1) in my original post.

Re: Possible Conversion Project??

Reply #3 – April 19, 2022, 09:17:59 AM

Cheers guys, yeah, it's cost me a pretty penny or two, estimate 8k by the time it's all said and done (including 2k for the car).
I've tried to do as much myself as possible, so I've got around 300-400 hours in so far.
I'll probably have to get it valued, as I've got no idea what to insure it for.

But if you want to take the engine parts out, and have a mint chassis/running gear, you can probably get that down to around 6.5-7k.

Re: Possible Conversion Project??

Reply #4 – August 22, 2022, 09:02:59 PM

Possible source motor parts, has anyone considered using the motor unit from a Golf E, since its based on the Mk4/5 platform the mounts should line up with the standard fittings a la 20v conversions.  Plus its VW so keeping the faith,  driveshafts should all work to, you then only need 3rd party controller as I doubt the VAG unit is going to want to plug and play unless you transplant the entire loom and plug in everything as it was.  Add to that the battery of choice and you are on.

Seen the Golf E units go for around the £500 mark so on par with aftermarket stuff that you still need to make up linkages and gearbox plates etc.

Have considered it for my Auto, but not started anything yet.

Re: Possible Conversion Project??

Reply #5 – August 23, 2022, 07:51:50 AM

Having driven a Golf e, I wouldn't want to go to all the trouble of a conversion to make the car slower that a stock gti.
Might be better in a mk2, but the mk7 platform I drove felt awful, very slow to react and lethargic in general, I ended up buying an i3.

Re: Possible Conversion Project??

Reply #6 – August 23, 2022, 08:44:22 AM

Interesting discussion.

I've been following Damien McGuire's experiments on YouTube (he's been at this game for around 15 years).  The latest is about how to exploit the rather impressive Toyota/Lexus transmission (designed for hybrids, but which can be adapted to dispense with the ICE).

Here's quite a bit of YouTube stuff about Damien McGuire's experiments and research.  The first video in the link below is nearly one-and-a-half hours long, but I would recommend watching the first hour, if you can bear it, as it covers lots of core principles and common misconceptions:

https://www.youtube.com/watch?v=qBZ3g8QTmwE

The following are helpful videos in a series.  I have marked one ones I think are particularly informative [info in square brackets].  If you copy and paste any of the lines (up to and including the number) into YouTube, the video will come up:

Lexus Toyota Hybrid Transmission Project 01 : Introduction
Lexus Toyota Hybrid Transmission Project 02 : Internals [Vital concepts]
Lexus Toyota Hybrid Transmission Project 03 : First Spin [Basic running)
Lexus Toyota Hybrid Transmission Project 04 : Due North [Resolver function]
Lexus Toyota Hybrid Transmission Project 05 : Noisy Neighbour
Lexus Toyota Hybrid Transmission Project 06 : Damien is a Moron [New realisation]
Lexus Toyota Hybrid Transmission Project 07 : Torque Setting
Lexus Toyota Hybrid Transmission Project 08 : More Torque
Lexus Toyota Hybrid Transmission Project 09 : Smooth Runnings [Problems overcome]
Lexus Toyota Hybrid Transmission Project 10 : High Voltage High Speed
Lexus Toyota Hybrid Transmission Project 11 : Oil Pressure