VW No Gas

With the legal stuff out of the way, I could finally start working on the car itself. The first step was to remove the gas tank and engine–and buy car-tools! Keep in mind, I’m not a car guy, so follow these steps at your own risk. I’ll cover what I did to the car and then the decisions and early purchases for the electric conversion after that.

Removing the Gas Tank

I wanted to start easy, so the bonnet/frunk was the first order of business. It came out fairly easily with a few bolts. The gas was either turned solid or had evaporated over time, so I didn’t have to worry about draining it. I found an old wrench under the gas tank–50 years entombed. The hardest part was getting the filler neck disconnected and out, but it was basically: keep removing bolts and clamps until it came out.

The big black thing is the gas tank.

Here it is with the gas tank removed. I added labels to the tubes and wires for reference later. Many of them won’t be needed, but I wanted to be able to identify them later if needed.

After that, I sanded/ground down the rust, taped and surrounded everything with plastic sheeting, and applied a couple coats of primer and paint. I chose to a basic grey primer and a stainless steel paint so at first glance it might look like the original metal. I definitely got paint on some of the tubes and wires, but overall, I think it turned out well.

Removing the Engine

I watched this YouTube video at least 4 times to prepare for removing the engine. He drops a VW engine in 10 minutes, by himself, with 2 jacks. It gave me confidence that I could do it too. Or rather, it gave me confidence my friend could help me do it. I have a small handful of very car-savvy friends, so I called up Tyler and asked for help.

He brought his kids over for a playdate and we got to work–his tools are way better than mine, and he has the experience and know-how I lack. Also, it’s way more fun to work on cars with a friend. I had already removed the cover pan and air filter assembly before he got there. It took 1 hour to get the oil drained, everything disconnected, and teh ancient bolts removed. The second hour was mostly wiggling the engine and trying to get an extra inch of clearance (we had to take off the exhaust manifold to get it out). But we did it without a single drop of blood or trip to Harbor Freight.

I gave the engine bay the same treatment as the bonnet: sand/ground down the rust, taped and surrounded everything with plastic sheeting, and applied a couple coats of primer and paint. It turned out pretty well, I think. The hard part here was getting all the rubber gaskets out of the channels–it was brittle so a lot of it was pulled out in small pieces that littered the floor.

EV Build Decisions

A lot of videos and articles were consumed over the last few months on EV conversions. There are a lot of strong opinions out there. Here are some of the decisions I’ve made so far.

Motor & Drive Assembly

The most popular motor for a VW conversion is the NetGain HyPer9. It’s an AC motor with a lot of power and can leverage regenerative braking. Initially I was planning to go with that. However, after a lot of research, I decided to go with an older model that is DC: the NetGain WarP9 (plus I can say I installed a Warp Drive!). The main reasons are cost and simplicity. The WarP9 is significantly less expensive, and DC motors are simpler to wire and control. I don’t need the extra features of an AC motor for this project, so the WarP9 is a better fit for my needs. The VW Bug doesn’t need the torque to drag race–my car friends are probably disappointed to hear that, but they know I drive a Prius like a grandma and this bug isn’t going to change that.

A new HyPer9 sells for ~5400 (plus a lot of shipping). A new WarP9 sells for ~2000 (plus shipping). I got a used one for $1450 + shipping. If I hadn’t mentioned it before, I really like finding good deals.

These can be attached in basically two ways: direct drive (motor connects directly to the gearbox with a coupler) or with a flywheel/clutch assembly. Direct drive is clearly simpler, but it requires that I stay in 2nd or 3rd gear permanently (the motor has enough torque to start from a stop in 2nd gear). Using a flywheel/clutch assembly allows me to use all 4 gears like normal, but adds complexity and cost. After thinking it through, I decided to go with direct drive. The simplicity and lower cost outweigh the benefits of using all 4 gears. Because I won’t have a clutch, I need to find or make a way to lock out all gears except for 3rd and neutral (for towing). The warp drive can manage starting and cruising in that single gear and it can also go into reverse electronically.

In order to do that, I need 2 pieces: a coupler to connect the motor shaft to the gearbox input shaft, and an adapter plate to mount the motor to the gearbox. EV West has kits, but they use the flywheel approach. I found two options for the adapter plate and picked one (fuel2electric.com). The hardest part on the adapter plate was the right terminology. The motor side of the adapter can be called a “NEMA B Face” and the other side needs to fit a “VW Type 1” gearbox. The coupler is another matter altogether. I need a coupler that fits on a 33 tooth splined shaft and a keyed 1.25” motor shaft. No luck so far, but I’ll figure it out eventually–I’m waiting for an email back from a potential supplier.

Battery Pack

The power system is the most complex and expensive part of an EV conversion. There are a lot of options out there, and I want to make sure I pick the right one for my needs. After a lot of research, I initially decided to go with a lithium iron phosphate (LiFePO4) battery pack. But after watching several videos and reading more articles. I discovered that the aftermarket ecosystem for EVs has a LOT of support for used Tesla batteries. I also didn’t realize how affordable they had become.

So I ordered 5 Tesla Model S Battery Modules (24V 250ah 5.3kwh) which will put me at ~26.5kwh and ~120V, which should get me between ~90 miles of charge depending on driving conditions and other factors (ac/heat). I bought all 5 for ~$1500 including shipping (wow they’re heavy). They’re in the mail.

Battery Management System (BMS)

The batter management system is a critical component of any EV. It monitors the state of the battery pack, manages charging and discharging, and ensures the safety and longevity of the batteries. There are a lot of options out there, but the Orion 2 seems to come out on top for all the videos and kits. The problem is that they pricy and you have to replace the Tesla onboard battery BMS with a custom passthrough harness. After looking further, I discovered that SimpBMS has a kit specifically for Tesla modules that is significantly less expensive, smaller, and easier to install because it relies on the existing Tesla BMS. I haven’t pulled the trigger on this yet because I have a few more questions to get answered, but it’s looking like the best option so far.

Simpler, cheaper, more maintainable.

Other Things

There are a lot of other components I need to figure out: motor controller, DC-DC converter, charger, fuses, wiring, etc. I’ll cover those in future posts as I make decisions and purchases. I’m not in a rush.