[askme233]

I have both and both have sen better days and need serious ICE work. So I am considering an EV conversion. I had assumed the 912 would be a great EV and noticed there are ready-made kits for it.

The BMW is my daily driver but on its last legs. It dawned on me that the BMW is likely a better all around chassis, much more modern and might make a better conversion.

I had had my heart set on the 912.

Help me decide. What should I be weighing?

 

[onegreenev]

As a daily driver the BMW will be better but the 912 will be more fun and much lighter in weight. Still quite sporty if you use the right setup. If you don't mind crawling into the 912 all the time then its a no brainer, the 912.

Don't forget, the 912 will more than likely have NO air conditioner except when you roll down the windows.

 

[askme233]

As a daily driver the BMW will be better but the 912 will be more fun and much lighter in weight. Still quite sporty if you use the right setup. If you don't mind crawling into the 912 all the time then its a no brainer, the 912.

Don't forget, the 912 will more than likely have NO air conditioner except when you roll down the windows.

Thanks. The AC went on the BMW about 5 years ago anyway...

 

[madderscience]

If the 912 chassis is in good shape it would make the "better" conversion from many factors: chassis simplicity, weight, aero (top on), etc. Since you can buy an EV these days for a lot less than it takes to build an equivalent performance one (especially if you buy one a couple years old) The value proposition for the car has to be in the uniqueness or novelty of it, and a vintage porsche should beat a 90's BMW any day on that count.

That said, ultimately it comes down to which car you most want to spend $10K or more on and want to keep as long as possible and drive as much as possible, but knowing its resale value won't be much. If you do convert the 912 consider doing it in a 'reversible' way (don't cut the chassis to make room for batteries) That will help preserve value as a vintage car. With the BMW, hack away, who cares...

Good luck

 

[askme233]

If the 912 chassis is in good shape it would make the "better" conversion from many factors: chassis simplicity, weight, aero (top on), etc. Since you can buy an EV these days for a lot less than it takes to build an equivalent performance one (especially if you buy one a couple years old) The value proposition for the car has to be in the uniqueness or novelty of it, and a vintage porsche should beat a 90's BMW any day on that count.

That said, ultimately it comes down to which car you most want to spend $10K or more on and want to keep as long as possible and drive as much as possible, but knowing its resale value won't be much. If you do convert the 912 consider doing it in a 'reversible' way (don't cut the chassis to make room for batteries) That will help preserve value as a vintage car. With the BMW, hack away, who cares...

Good luck

Thanks for the reply. I am intrigued by your comment on dropping $10k for a performance car. Everything I have seen as been easily double that.

This kit seems quite reasonable for $7k, but doesn't include the batteries.
http://www.evwest.com/catalog/product_info.php?products_id=221

Batteries would be another $5-$10k easily if I go for more modern batteries.

The 911 in this video had dual AC34's and 54Kwh in Tesla batteries, so perhaps another $13k.

I don't want screaming performance (the 912 was never really that fast), but I don't see how I get out for less that $20k.

 

[Duncan]

Hi ask
I don't want screaming performance (the 912 was never really that fast), but I don't see how I get out for less that $20k.

My costs (Duncan's Dubious Device)
Motor $100
Controller $600
Batteries $3000
Charger $150
That gave direct drive and reasonable performance

Since updated to
Controller $1000
Chevy Volt battery pack $3300 (including shipping and taxes to NZ)
Charger $500

That gives tire spinning performance

 

[Moltenmetal]

Duncan's build is inspiring, but he did a lot of work including finding and modding a forklift motor, building his own controller from a kit etc. He's also running without a BMS with a Chevy Volt pack which is risky- you personally would become the BMS, which is fine until you get lazy or something screws up without you noticing. So you can save a lot of money in return for both sweat and risk. But the big DC motor gives you serious grunt for the dollar, if grunt is what you really want.

 

[askme233]

Hi ask
I don't want screaming performance (the 912 was never really that fast), but I don't see how I get out for less that $20k.

My costs (Duncan's Dubious Device)
Motor $100
Controller $600
Batteries $3000
Charger $150
That gave direct drive and reasonable performance

Since updated to
Controller $1000
Chevy Volt battery pack $3300 (including shipping and taxes to NZ)
Charger $500

That gives tire spinning performance

Consider me inspired. Seems like the secret sauce was sourcing that motor. What kind of car do you have it in?

It seems like I will have a decision point on getting everything I want, but doing it myself with self sourced parts (the way I do all my electronics) or paying for a pre-configed solution, but paying retail and/or compromising.

 

[Duncan]

This is my car

http://www.diyelectriccar.com/forum...dubious-device-44370p15.html?highlight=duncan

The motor is an 11 inch diameter Hitachi

Electric forklifts are quite common - you will find them used where food or anything that would be hurt or made dirty by exhaust fumes is stored or moved

The result is that there are lots of them about and when their batteries die - or their controllers - often the forklift is simply scrapped off

The trick is getting the motor before the scrap man smashes it!

You will need to go around to the forklift repair place with some cash (or beer) - until you are there at the right time

I dropped in to our local guy yesterday - and he had sent all that he had to the scrap the week before!

My motor came out of a 4 tonne Nissan forklift

 

[e^2]

I am going to have my setup for $5k.

$900 for used 8" ADC motor
$400 for a 500A controller
$2500 for 19kW of lithium
$500 for an old EV project

But I would still do the 912 if you want to go fast. Do the 328 if you want to take a passenger or do any commuting.