Update: Porsche 911 EV Conversion

Our story so far:

In 2022, I signed up with Moment Motors to get in their queue for an EV conversion.

Thus began the hunt for a donor car. I mentioned last month that the originally selected car for this project turned out to be a rare(ish) 1988 Porsche 911 Cabrio that I did not want to devalue; instead, I restored the little cabrio back to factory spec (photos here) and decided its a keeper.

What I ended up finding for this project was a 1987 Carrera with nearly 300,000 miles on it, and a lot whole of factors that argued against any pricey restoration: replacement motor, period incorrect side view mirrors, wrong seats, 90’s steering wheel, etc. It had been in an accident to its right front end 20 years ago but was repaired + repainted (more on this below). I don’t know if/when the doors were replaced (post-accident?) but they are a slightly different color. Kind of a hot mess…

The coupe started out as an interesting project car, with a few rare options. The color is lovely and unusual “Lagoon Green Metallic” which reads as a light blue to me; the paint was mostly clean; it has rear-wiper and a sunroof delete. It made sense to restore the M491 Cabrio back to stock, as it was still worth more than the purchase price plus the costs of repair. On a “Frankencar” like this, that made no financial sense.

It took a year for my place in the queue to come up. In August 2023, I shipped the 1987 911 coupe to Texas for its EV heart transplant. It’s been a while since I last discussed where we are with the project, so I thought I would share some updates as to our progress. It’s been mostly good news, with a few surprises thrown in:

The good news: The little striped monster arrived in Texas in good shape, with no issues from transport. I had dropped an Apple Airtag in the glovebox to track it across country (travel time was about 3 days).

Soon after arrival, the Motor and transmission were removed without a hitch (photos below). Then the new HVAC system went in, as did a retro period-correct Blaupunkt Bremen SQR 46 DAB head unit (Bluetooth no screen!). (I’ll eventually replace the old speakers.)

The surprise was that a known rust spot — the area around the 12-volt battery (nestled against the driver’s side front fender) — was much worse than thought. It had rusted so badly that it was affecting the structural integrity of the front trunk where the new EV batteries go — at nearly 200 pounds, they need solid support. You can see the before and after photos below. $9k later, it’s as good as new.

In late December, the EV motor arrived. When we began this project back in May 2022, the state-of-the-art was the Fellten EV Series 1 motor. At 350hp, it was a nice bump up from the car’s original stock 210 hp flat 6.

Alas, the Series I ended its run, and so we were delayed in getting the Series II Fellten kit (see photo below). That delay was worth the wait as the Series II horsepower is 440 — more than double the original stock engine. That is a helluva a lot of go for a 2500 lb car. For comparison, a 2012 Audi R8 has 420 horsepower and weighs ~1000 pounds more. The 0-60 times are similar, but I suspect the little 911 will feel faster.

I’ll update again once the motor goes in; Photos of the progress below:

Previously:
Update: Electrifying A Classic 911 (May 21, 2023)

Electrifying Classic Cars (September 4, 2022)

1983 Porsche 911SC Coupe – EV? (September 16, 2022)

1988 M491 Porsche 911 Cabrio (January 21, 2024)

Engine out: