Project Land Yacht (BMW 5-series EV conversion)
 

Firstly Merry Christmas to all:) Secondly I'd like to introduce the new project that i have christened the land yacht! Donor vehicle is a 2001 BMW 520I E39 5 series. Equipped with a 6 cylinder 2.2L petrol engine that has a few minor problems:) This is going to be replaced with a 13" rebuilt forklift motor , 1200amp controller , 15kw 3 phase charger and a pack of 60 CALB 180Ah grey cells. Let's see what happens ........

http://www.youtube.com/watch?v=WZTtci674fE

http://www.youtube.com/watch?v=CPY4kvVpn6s

Bit more progress .....

http://www.youtube.com/watch?v=iXhOBl0xljw

Woo, sounds like a fun project. I'm anxious to see how the CALB grey cells work out for you. Everything I've heard about them is that they're a very nice battery. Looks like with that many you should have some pretty good range too. I'm guessing 80-100 miles.

I also gotta laugh at the 5 series being called a land yacht. Many here wouldn't even consider anything smaller...

Brilliant! I will be watching this.
I love Beemers. I want to convert a 3-series in the worst way.

I take it you went with a clutchless system due to the amount of torque you'll be transmitting? Do you have any solutions for quicker shifting?

I also love Bimmers. But if I would ever consider to convert one to all-electric drive I'd consider to remove the gearbox and use one of those reversible motors, to take some weight away and eventually leave more room for a bigger set of batteries.

Unfortunately, direct driving a car requires a very large motor - 11" or 13" or larger - and the increased weight offsets the weight savings of ditching the transmission. One possibility is two 9" motors end to end and parallel/series switching them to achieve both the required start off torque and high speed.

The beauty of converting RWD cars is that the transmission is out of the way to begin with, leaving much more room under the hood for other goodies. Ridding the engine compartment of a motor (moved to the ex-transmission's spot) doesn't really gain a whole lot.

In all my research, it seems that the only proper solution is to keep the transmission. Even though electric motors have a flat torque "curve" (line?) down to almost zero RPM, they do not have a wider effective RPM band than gasoline engines. One gear is never enough, unless of course you spend big money on high end AC componentry. But even the Tesla roadster has two speeds.

13"? Check :thumbup:

An electric-drive usually is a good field for experiments and improvements in the course of the project anyways...

I do not even understand what you are doing, but I wish you the best of luck!

Man....looks like you are set. When is your EV build starting?:)

Not so soon, but a friend of mine has been lurking around it for quite a long time.

Latest update :
http://www.youtube.com/watch?v=os8GtMsCxAo

Thanks for the comments guys. I had never driven a 5 series before and the comfort and smoothness even on ICE power was very impressive. The thing just glides over bumps and potholes that would rattle the teeth in a dfferent car.

Regards the clutchless coupler I had a couple of reasons. First my experience with clutchless shifting in the e36 has been very good. Nice and quick with no snatching or grinding of gears. Unfortunatly in Ireland there are very few engineering shops that would do the work of making up an adapter plate and coupler and those that might would be prohibitively expensive. So i'm kinda training myself and building up the necessary equipment to do this work myself. The 5 series uses the exact same gearbox so i'm not anticipating any problems. I have also removed the motor fan as it will be externally forced air cooled so this should help allow the armature to change speeds easier when the synchros mesh. This gearbox is also very light. I can carry it one handed so the weight penalty versus having 5 speeds to choose from is very slight.

I was just wondering if you were planning on doing anything interesting with the motor controller for shifting. I don't know if you did anything with the E36. But, since you have an rpm sensor on the motor you could also install one on the transmission input shaft. When shifting it would be fairly easy to rev match the motor to the trans for very smooth shifting. A friend of mine sort of did something similar with his EV. The difference was he just had a button to make the motor spin ~2k rpm which made it easier to shift (it was an AC motor setup).

In any case, the adapter plate looks pretty good. Can't wait to see that engine ripped out! :)

I also added some additional description to your thread title.

Looks amazing. Pretty good for "a complete amateur at this", as you put it!
Once again I am completely jealous of another man's EV build.

Agreed, you already built one EV, you're no amateur. :p

thanks for the kind words guys :) I must do a video of shifting in the E36. Its really smooth and to be honest easier in my opinion than the conventional clutch shifts in the ICE version. The way the power comes on after a shift is just a million times better than the rattle and roar of the ICE!

Though not quite related to the build here is a high discharge test of a 180Ah CALB grey cell
http://www.youtube.com/watch?v=lyYfFeWwd9I

:thumbup:

I always thought that the old e30 chassis would be a good EV platform, even the 5 series look big in comparison. If it originally had the ETA motor then the gears would probably be about right for electric, plus they are surprisingly cheap for a rolling chassis. Never been in a newer bmw like yours so I cant wait to see more video, they always speak for themselves

subcribe.

1500 kg roughly, less than I thought for that sized car. I guess not all german cars are as heavy as my diesel merc! Should make for a nice ride. Amazingly small gearbox.

Adding a post to mark this- something I'd be interested in! Looks good!

One question- is it easy to insure a conversion like this?

thanks

Insurance on an EV conversion is a common question.

The simple answer is YES you can get insurance, and look before you start the project.

I had no problem getting insurance on my electric car conversion through Progressive. I was also using a full-service insurance agent, and explained to her exactly what I wanted to do before starting the project.

Other things to check on before you start your project include, license, title, registration, pollution control tests, and local, state, and federal laws.

Rules and regulations vary considerably from one area, county, state, country, to another, so look to see what applies to you.

By planning ahead, you can have a project you are proud of AND be able to legally drive it!

Here's a few more comments on it at my blog.
http://300mpg.org/projects/electro-metro/insurance/

It looks like you're going to change your signature now since you have batteries capable of delivering 2000 amps! :thumbup:

Insurance can be an issue especially in Europe. I was lucky enough to have a broker friend who did a lot of leg work to get it sorted. The thing is its all precedent. Now that the company have covered me in one ev another is no problem.

Last weekend I jacked up the front of the car for a look see as I had a sneaky suspicion that I may have a clearance issue between the motor frame and steering rack. Sure enough unlike on the E36 where the rack is mounted on the side of the crossmember on the 5 series its on top! Bit of headscratching later I think I have a solution. I picked up a driveshaft for the automatic version on ebay which is shorter than the manual. This will let me more the gearbox / motor assembly rearward by about 3 inches allowing the motor to clear the steering rack. I'll need to shorten the shifter linkages but that's only a bit of welding. Plenty of clearance in the tunnel. I doubt even a 9" motor would fit without this modification and I want the power of the 13" :)

This is what I'm looking at for the aircon :
Toyota Prius 2nd Gen XW20 (2003-2009) 1.5L Hybrid Air Con Pump ACP638 | eBay

Couple that with a 2hp vfd and i'm up and running with aircon for less than 300 euros. Just need to graft the prius pipes to the bmw but again that's just a bit of silver brazing.

Here's the latest on the yacht!:
www.youtube.com/watch?v=3kKFYM060tY

I've attached the arduino sketch in txt format. I'd be grateful if someone could have a look and tell me if it outputs 58 pulses then misses two as i don't have a storage scope at the minute!

Megasquirt community is a good source of info on topic, take a look for example here: Megasquirt MSEXTRA / MS3EFI • ms1e 60-2 wheel can't get wasted spark to run (View topic)

edit: stupid me, misunderstood your question ;)

This is awesome!!!!

For a functional tachometer, why not remove the tone wheel from the ICE's crankshaft, install it on the DC motor shaft and mount the crankshaft speed sensor in the appropriate spot? No need to fool the ECU - simply give it a real speed signal.

I would also use some other useful ICE sensors, like mounting the coolant temp sensor somewhere on the motor or controller so you have a functional temp gauge.

Few reasons I can't do that. First is that its buried in the engine , second i dont have an aux shaft on the motor and third if the signal drops below 250rpm the mil light illuminates. While that presents no practical problems driving the car it would result in a failure during the mandatory vehicle testing which I will have to do. So the arduino will produce a false 300rpm signal to the tach when the motor drops below 300rpm.

Got it.

Are you going to attempt to use the tach for motor speed at all or will it just always read 300 rpm?

Yes the tach will read motor speed above 300rpm. The motor will have a 2 pulse per rev signal being fed to the arduino. this will do the math to turn that into a 60-2 reluctor wheel signal and feed it to the ecu. When the actual motor revs drop below 300rpm the arduino will maintain a 300rev signal to the ecu. Then when the motor revs over 300rpm it will revert to actual. Hope that makes sense :)

Wait a minute! You are designing an electric car that will pass the pollution inspections that the gas version of the car must pass?!!?

Brilliant! :D

Yeh pritty much Ben! My current ev failed its first test a few years ago cos they couldnt find a place to put the exhaust gas probe!

I'm glad to hear you're keeping the transmission. I think many converters think they can do without it, but your comment about limited RPM range is right on. I kept my clutch, and my car drives like a ICE version. It's interesting to hear you don't have issues with shifting without the clutch. I would have never thought that. For my car, my torque almost matches the peak torque of the ICE engine, so I didn't worry about burning out the clutch. I machined the the flywheel down to the outer diameter of the clutch to reduce the rotary inertia losses from the flywheel. Unless your torque is way over the clutch limit, which means your over the whole drive train limit, I still think maintaining a clutch is a good idea. I see these incredible builds where the people say they left the clutch out to make it easier to do. I keep thinking that after all that work, you didn't bother to keep the clutch? Good luck on this build, though I don't think you need luck, you already know what you're doing.

It depends on the motor size. My small 7" motor shifts exactly the same as if you pushed the clutch in (when it had an ICE) even though there is no clutch. A 9" or 11" motor will definitely roast synchros in no time.

My next build will definitely have a clutch.

The 5 series uses the exact same getrag 5 speed gearbox as I'm running in the 3 series which has just passed 20k ev miles without a clutch and an 11" motor. Two things help here : I would only do about 20% of the shifts in an ev as i would do in an ice and secondly the getrag has very good synchros.

Latest on the yacht. Still working out signals etc waiting for the weather to improve and components to build up before getting stuck in :

https://www.youtube.com/watch?v=kywdJYL_hc0

Preparing for the motor install :
https://www.youtube.com/watch?v=2yimzNGl8II

Did you mean to have pictures in these two posts?