"New" EV For Me: 1973 Saab Sonett Conversion

Well, after about a decade of waiting I finally took the EV plunge

I started seriously planning a conversion back in 2004-2005, but finally decided it would make more sense to just buy a Prius. I've loved the high mpgs, and the car in general, but never lost the EV bug. Recently I've been trying to decide whether to finally replace my '05 with one of the many excellent EV or PHEV options available out there, but decided in the end to hang onto it and pick up a project car to convert as a commuter.

I've always had a soft spot for these odd-ball Saab's, ever since owning one (that I could barely keep on the road) back in the late 90s. When researching platforms for a conversion, I was rather pleased to discover that they seemed to be an excellent candidate. With a curb weight of 1800 lbs, a Cd of 0.31, and a miniscule cross sectional area (22% smaller than 1st Gen Insight), they were fun to drive with the stock ~60 hp engine while averaging 30-35mpg in a day when 10-15mpg was typical. They were also designed as racers, being proven as a great platform for performance enhancements and doing quite well in their SCCA and rally classes.

I wasn't planning to start my search in earnest for another month or two, but when this example came up for sale locally, I couldn't say no It was about the same price that I would have spent on a fair condition runner in need of complete restoration, but had already had a simple DC conversion done in the 90s and a significant amount of work had gone into restoring the frame/floorpans and mechanicals as it passed through the ownership of two different vintage Saab restoration gurus. If nothing else its a great rolling chassis to build on, with a bonus that the old conversion has been maintained and rebuilt well enough to still be used as a commuter in the mean time

With a 6" GE forklift motor, 96V worth of flooded lead acid golf cart batteries and a souped up golf cart controller its certainly not going to win any speed or range prizes, but I'm still all giggly I'm going to start planning an upgrade to a modern AC drive system and Lithium battery pack, but in the mean time its a hoot that I can start doing my commute all electric already!

Rob

 

Thanks Bisco, always loved the p1800 look What really sold me on the Sonett for a conversion was the fiberglass body and low weight. Stock curb weight is about 1800 lbs, and "empty" the rolling chassis is about 1300 lbs. Since kW tends to = $ in an electric drive, low weight and good aerodynamics are a big enabler to performance (acceleration, range, efficiency) on a reasonable budget.

I'm sure its optimistic, but doing some modeling on the "Excel Dyno" () taking the 80kW drive system from a 3300 lb Leaf and putting it into a light platform like this could yield some "entertaining" results



Acceleration characteristics are modeled in the third to far right column (under "toggle units") for the Sonett with Leaf drive. The values for the leaf body with the same drive train are pasted into the scratch space at the far right. Could be fun if you can keep all that torque applied to the road

Rob

 

Still researching, but pretty tempted to go the salvage leaf route

 

Its pretty funny, when I drive my prius now it feels both plush and peppy Anyone that complains about the acceleration or ride comfort of the Prius should spend a week driving my new ride, they'll be cured for life

Having a great time with it so far all the same

Rob

 

BTW finished my first "mod"

Its getting pretty hard to find anything to monitor large lead acid packs on the market anymore (can't imagine why), so I built a circuit to adapt the battery voltages down and buffer them in a range where they can be read by a cheap celllog battery monitor (of RC and Enginer fame). Seems to be working well so far, though this is just a prototype I'm using the Celllog 8S so I can record data and then download over USB for analysis.

 

Looks like I got lucky! Bought a wrecked 2012 Leaf w/24k miles from Copart/Autobidmaster. Ended up being just under $7k with fees and shipping from WA to AZ. Looked promising, but you can never really tell what you are going to get with these salvage auctions.

2012 NISSAN LEAF SV/SL - Copart


Leaf arrived today, had low battery warning and 6 miles range remaining, but started right up and drove off the truck. Small number of minor DTCs, after clearing with LeafSpy no DTCs reappeared. All fluids seem to be holding level (coolant, etc), AC works fine. Printed a temp permit and drove (very slowly) to Nissan dealer 3 miles away, still showing 6 miles range. Tried level 2 charging, started right up at 3kW. Switched to QC, charged to 80% in about 40 min at 17-18kW. Battery showing 11/12 capacity bars. Drove to work with AC (~10 miles, 92F) with no issues, glides well, brakes straight, no wheel pull or vibrations. Still no DTCs after drive, ~60 mile range still showing and average >5m/kWh for the trip. Pretty jazzed!

Now the real fun begins

Rob

 

Correct, radiator and electric water pumps to cool motor and inverter.