BMW 3.0 CSE

In order to accurately test battery fitment, I had to mount the front suspension cross member so that I could install the steering gearbox.  The batteries will need to clear that.   I had spent months rebuilding all the brakes and suspension for the car, prior to deciding to go electric.  Fortunately, all those parts should work fine with the EV conversion. 

As mentioned previously, with the differential mount cut off the rear suspension I needed a new way to properly locate and secure the rear suspension member.  Tyler fabricated a long arm that welds to the front side of the member and travels forward into the old driveshaft tunnel.  Of course, I no longer have a driveshaft so that room is up for grabs now.  Using a motor mount from a Chevrolet Suburban, we welded a mount to the tunnel and bolted the new arm to the body via the rubber mount.  This is solid fore/aft but allows a bit of up/down swing if necessary.

The theory has been proven.  We drove Paul's coupe for the first time!  While my car is still a ways away from moving under its own power again, we got Paul's on the road, complete with a working prototype of my dash app.  

I have the motor controller for the Tesla motor and plan to integrate that with a Raspberry Pi micro computer over a CAN bus for instrumentation (not using it for gear selection -- there are 12v inputs on the controller for gear selection so I plan to fab a unit with detents and a delay relay that will integrate with the original BMW automatic shifter but that's a future project). 

Tesla motor, axles, and batteries have arrived. Unlike Paul, who is using the large Tesla motor, I have opted for the small rear drive motor. My goal is 300 hp and 200 miles of range. Not the 450 hp Paul is shooting for. 300 seems like plenty to me, given the stiffness (lack thereof) of our skinny pillared unibodies. Plus, the small motor sheds 100 pounds vs the large motor and is physically smaller, allowing more battery placement flexibility. Tesla Model S drive unit and axles.  I only need the inner CVs from the axles as they are much too long for the narrower BMW Like Christmas, 14 Tesla Model S battery modules, packed in foam The Tesla batteries are temporarily stored in a wooden rack The packing foam is useful for testing fitment of the batteries This first step in getting the drive unit into the car is to re-enforce the rear of the car to support it and provide the necessary mounting points. Plenty of space to work with now Strengthen those wheel tubs as much as possible We ...

The truth is, most of the time spent in this "EV conversion" has been spent on body work having nothing to do with the EV project. I knew there was some rust in the right-side floor and in the rear corners of the rockers but we also found rust: Between the roof and the sunroof frame In the lower front fenders In the left rear floor panel In the pinch weld of the rockers In the front and rear window frames To be safe, we removed the entire sunroof structure, fabricated a new portion of the roof, welded it in, and then replaced the sunroof.  Getting the roof curve correct and straight has been very time consuming. To be safe, we removed the entire outer rocker so that we could see the condition inside.  It was fine but at least know we know that for sure.   To be safe, we replaced the lower section of the quarters and fenders on both sides. We replaced both rear floor sections and patched the front. At least now we ...

It all sounds so easy.  Just throw out that old gas engine, bolt up an electric motor, add a few batteries and you're off to the races.  Or at least to the corner ice cream store in your new electric classic car.  If it only it were so.

The Tesla parts should arrive in a couple weeks. In the meantime, we've cut out the trunk area in anticipation of the motor install (I'm using the smaller Tesla rear-drive unit, by the way) so there's no going back now. The goal is 294 HP and 200 miles of range. There are still many, many details (battery placement, P/S, P/B, A/C, cooling, etc., etc.) to figure out.

The coupe was begging for updates.  Disassembly began in November, 2018 with the intention of upgrading the driveline to a modern early 1990s vintage BMW fuel injected 3.5 liter M30B35 and 5 speed manual transmission. After acquiring a new motor and trans, I ran across a guy named Paul Dexter who was converting his 3.0 CS to electric using a Tesla motor and batteries.  This was inspiring. 

I bought a "nice from 15 feet" 73 Baikal Blue USA Automatic coupe off eBay back in 2015. My wife and I drove it home from NorCal but the secondaries were stuck closed in the Webers and the trans wouldn't kick down. I spent a few years fixing little things and driving it. It was fine but there was some rust (spare tire, right rear floor, rocker rear corners) and it smoked a bit on deceleration so I decided to embark on a motor upgrade and undercarriage cleanup, without messing with paintwork yet. I'd save that for a full resto at a later date.