This is a 1991 Golf Mk2 GTI. The customer got in touch with us and said “hey, I’ve seen that you've done a camper van, and I see that you've done a Porsche 911, could you do a Golf GTI as well?” to which our answer was “well, yeah, we can do that no problem”. We immediately got stuck into the dimensions of the vehicle to look about the physical space. That was the biggest restriction with such a wonderful little car as this. We elected to go for a small Tesla rear drive unit which is 270 brake horsepower, about double what it had originally. We have a split battery pack in this option, some modules underneath the bonnet where the engine used to be, and some modules in the boot. That was elected to be able to give us a real-world range of over 200 miles per charge.
Under the bonnet is half of a 54 kWh battery pack sitting on top of a custom subframe, that's also housing our small rear drive unit from the Tesla. Inside here we've got our battery modules, we've got a custom cooling system over the side which is for both the drive unit and the batteries. We've got electric power steering to replace the original belt driven power steering that plums into the original hydraulics; that's the thing that makes it sound like a spaceship. We've got our charger neatly tucked behind here; that's doing 6.6 kW home charging so you can recharge this vehicle in somewhere around five or six hours. You can also do that at public charging places and that's in addition to the rapid charging which is available through the front socket. We have CHAdeMO charging on this particular vehicle, future models will have CCS2 charging in the original petrol flap. We have a brake servo kit on here, we have a DCDC converter to keep our brand new 12 volt battery nice and topped up and it's got an Orion Battery Management System enclosed within the battery box keeping everything running really smoothly. Let's take a quick look at what's going on in the back of the vehicle.
In the back, we have our second battery box. On the top is a safety disconnect, so if there is any maintenance needed on the vehicle, or if the vehicle was involved in an accident; then the emergency services would need to be able to access that. There's no manual that tells someone where this will be because it's custom, so we have kept it quite obvious in this vehicle. The battery box itself has got a little contactor inside it and the cooling system is linked to the front box, plus a little bit of extra storage around the edges so we wanted to make the most use of that.
So let's take a look at the interior. We've kept the interior as sympathetic as possible. The main things that we've touched are the dash, which we've replaced with some CAN enabled, custom gauges. These show your miles per hour, your battery percentage, and also your current or amps gauge; which is effectively your rev-ometer. That's really nice because it shows how much power you're using and how much power you're charging or “regen-ing”. They've got built-in, little LEDs for your indicators and for your beam lights so they're really smart and really subtle.
Down here we have a little bit more of a change. In the custom buttons that were in the blanking plates; we've got our start button, which is the system that you can turn on with the ignition as you normally would with the key. Then after the vehicle has primed itself, and primed the battery pack, you need to hit that start button to go. That will then engage the ability of a high voltage to go through to the motor and let you move. Right next to it is our heater switch. That's a high voltage heater that we've built into the matrix itself, so you need to have the fans on for that to operate, which helps it to stop from overheating. That blows straight through the original ducting and trust me, after driving converted electric vehicles since 2013; having heating built in is really amazing.
Finally in here; there is no gear stick. It's effectively an automatic drive. You're using a single speed reduction gearbox in that Tesla unit. We've got two pedals: stop and go. That means that there's no gear stick and no clutch. So in the place where the gear stick was we have a gear selector that's a simple, subtle dial that moves from reverse to forwards and neutral. We've also got a motor temperature dial there as well. It’s not essential, but it's nice to know how the motor temperature is operating. It says motor temperature, but it's actually the inverter temperature. It’s that most delicate part of the drive unit so it's really key to us to be able to see how that's performing in certain operations. It's also great for diagnostics if, some way down in the future the vehicle wasn't performing properly, we can really quickly check and see what's going on with that too.
I love how simple this interior is. It’s this wonderful really deep grey tones, perfect for the era that these cars were so popular in. And I love how we've managed to subtly integrate the electric conversion without being too bling and too LED and too in your face. I also love some of the little features that we've got in here, especially the recline on these seats.
So let's have a little chat about what's actually inside our Golf Tesla conversion. You've guessed half of what's inside by what I’ve been referring to. We have Tesla power between the front wheels in our Golf GTI conversion. In this particular conversion, that's provided by a rear drive unit from a Model S or a Model X Tesla. In future versions of these we are going to be using the Model 3 motor. In addition to this we also have 24 CALB battery modules. This is a 3p4s module and it runs at about 16 volts. It's 2.2 kilowatt hours of capacity and we run 24 of these in series in our Golf. It's a split pack so 12 modules in the front and 12 modules in the rear. They're fantastic for providing the capacity and the power that we need to power this motor and to also get to the 200 mile range that's really desirable. Our new battery modules are 2.55kWh per module giving over 61kWh of total capacity and close to 230 miles range. We mount these into our vehicle on custom cooling plates that are structural for the batteries and also obviously help with the cooling, especially when rapid charging is involved. In our golf we have CHAdeMO rapid charging, but future models will utilise the newest CCS2 rapid charging which is 70kW charging speeds.
Looking at the motor, this actually is three different units all in one. You have the motor itself; that's a brushless electromagnetic motor and it's incredibly efficient so that is what's spinning and providing the motion. This motion then goes through into the central section which is a single speed reduction gearbox. So the motor spins the initial gear, that goes through a reducer and into the differential at the other end. The really delicate expensive bit is the inverter on the side. This needs its own dedicated cooling system the inverter cannot go over 80 degrees otherwise things melt, I speak from experience. We actually set a limit on this at 60 degrees Celsius, because if anything were to go wrong, if a pump was to fail or to get knocked, or the electrical supply to it get damaged; then the system itself will stop at 60 degrees; stopping it from getting to that dreadful 80 where things start to go wrong. The dc power from the battery pack comes in two cables down the side; positive and negative. The inverter, with a ton of settings, then inverts the signal from a DC to an AC signal through into the motor.
The Model 3 unit actually has the gearbox in reverse orientation. The golf has a rear drive unit from a Tesla, and a rear drive unit means that we've had to mount it in a front wheel drive vehicle. We've actually had to rotate this motor 180 degrees on the lateral to allow the differential to face the right way. The model 3 drive unit has the differential on the opposite side of the unit and what that means is that we would be able to just take a Model 3 unit and put it into a front wheel drive vehicle, it would just work straight away. This means everything's much smoother because it's a bit of a pain to get everything apart. Not only is that more time for us to do it; it's more risk of something going wrong which we hate we would avoid that at any cost. The model 3 motor is actually more efficient than the model s motor in how it produces power, and it's a slightly smaller package as well. All in all; we love it we've got access to those and they're going to be going into our future front wheel drive conversions.
So let's take a look at the interior. We've kept the interior as sympathetic as possible. The main things that we've touched are the dash, which we've replaced with some CAN enabled, custom gauges. These show your miles per hour, your battery percentage, and also your current or amps gauge; which is effectively your rev-ometer. That's really nice because it shows how much power you're using and how much power you're charging or “regen-ing”. They've got built-in, little LEDs for your indicators and for your beam lights so they're really smart and really subtle.
So in conclusion; is 200 miles range enough? Yes. Is 70 kilowatt charging speed enough? Yes. Is 270 brake horsepower enough in a Golf Mk2? Absolutely; yes, too much for my liking. That, to me, makes this vehicle an absolutely perfect conversion. If you're convinced then why not get in touch. We have all the fabrication ready, it's registered design to build more of these coming soon, so please get in touch go to https://edubconversions.co.uk/golf-mk2.
