# BMW 750IL-V12 as Donor???



## dtbaker (Jan 5, 2008)

with that weight, performance will be 'sluggish' compared to ICE w/ the 9" even w/ fairly high voltage like 144v or 156v I'd guess... but comfy I guess.  If you drop enough 160aH in there for 144v, you'll probably have plenty of range and probably have highway worthy top speed, but it may take a while to get there and/or struggle with hills.


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## etischer (Jun 16, 2008)

Is the car currently a manual transmission, are you planning on using a manual? 

I think it is a bit on the large side, cars don't get much bigger than a 7 series bimmer. For a first conversion I would urge you to choose something a little less extreme. 

For what it's worth, my first conversion was an '01 Passat, and I am happy with the performace. 4200 lbs, and 98.6 mph top speed. 0-60 in 16 seconds, 280A @ 280V


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## Bowser330 (Jun 15, 2008)

etischer said:


> Is the car currently a manual transmission, are you planning on using a manual?
> 
> I think it is a bit on the large side, cars don't get much bigger than a 7 series bimmer. For a first conversion I would urge you to choose something a little less extreme.
> 
> For what it's worth, my first conversion was an '01 Passat, and I am happy with the performace. 4200 lbs, and 98.6 mph top speed. 0-60 in 16 seconds, 280A @ 280V


+1 

For comparable performance you would need a bigger motor than a 9" and amuch better controller than a curtis...may i suggest a Zilla, Soliton1, or Raptor...something that can dish out 1000A (since your 160A batteries can @ about 6C)

I read somewhere that @1000A an 11" motor can put out 435nm (371ftlbs).. that should be enough to give you sufficient acceleration...

Edit: or you could get another 9" motor and use s/p shifting with the Zilla1K...

1000A to each 9" at lower speeds for a 0-60 time more in-line with the stock ICE...


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## roflwaffle (Sep 9, 2008)

Provided the curtis controller you have could pull ~500A, I think performance would be O.K. w/ a manual transmission that has sufficiently short gearing. My pickup is driveable at roughly the same weight and ~20-30hp less, although going up steep hills I end up dropping to ~40mph.


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## toddshotrods (Feb 10, 2009)

I would want a 13" motor in that one, with as many 160ah LiFePo4s stuffed in it as possible. Sounds like you're going to end up headed for three tons. You need lots of low end grunt to move it. Even if it will only do normal highway speeds on the top end, you want it to feel like it could pull half the city with it to that speed. Torque is usually an important part of the luxury car experience. With the right setup it would be a smooth, quiet, beast though. Rolls Royce is supposed to be working on an e-version. You'd basically be building a DIY version of what they plan to do.


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## bluefxstc (Dec 29, 2007)

Thanks for everyone’s input. It is great to hear all the ideas and opinions. The controller I have is an older Curtis with a 144 volt/500A limit so I plan on using 144V. The car has an automatic and I would probably stay with that although I would have to figure that part out. I have read the forum post on using an automatic but I’m still in the dark on how to actually do it. It will be part of the adventure/learning experience.  As for performance I am not trying to duplicate the ICE performance. That wouldn’t be reasonable but I would like it to be able to keep up with traffic. I am looking for a comfortable around town cruiser. 45 TS 160s are going to weigh 554 lbs. The 9 inch motor is around 140 lbs and figure another 150 lbs for other stuff (controller, battery racks, vacuum pump, wire…). That brings the total conversion weight to 850 lbs minus the weight of the V-12 and associated equipment. Any idea what the V-12 weighs? My original guess was that it would be close to weight neutral which would put the car in the 4000-4200 lbs range which would give me performance similar to Etischer’s, 0 to 60 in 16 sec although he is running 280 volts. I just need to replace volts with amps to get the same power output. I would be happy with 0 to 60 in 20 to 30 seconds so I should be in the ball park. My original idea was a smaller convertible with a converted weight in the 3000-3500 lbs range and I might still do that. I am just exploring the option at this point so I really do appreciate everyone’s input.
Thanks again.


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## dtbaker (Jan 5, 2008)

hhhmmmm, automatic tranny on top of other challenges would be enough to make me pick a different car.  Part of what we are probably going to learn (as a country) is that we need to make a shift in expectation when it comes to our perception of 'comfort' and vehicle size and amenities. I mean, how cushy a ride do you really need for a 20 mile trip?


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## Thaniel (May 25, 2008)

750IL is a HUGE car. I've been looking at 740IL's (same body) for a trip car for the family. The IL is only available in auto trans HOWEVER it can be swapped to a manual using parts from a 540I or so I have read. However being that the car will have a new engine it wouldn't be a big deal to use any trans you want. One from a 3 series would work for that matter 

I'm not sure about the "weight neutral" thing. How many pounds of batteries are you putting in? Using lithiums? I may have missed it. But the car probably has a bit of cargo capacity so it'll probably have lots of load rating for batteries. The trunk is absoluely huge so there is defiately room back there if need be.

Personally I wouldn't use a car that large unless ferrying lots of adults.

Thaniel


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## roflwaffle (Sep 9, 2008)

Depending on what year the Beamer is a dressed engine alone could be 600lbs and up. Dropping a manual transmission in would probably save another hundred lbs or so, and if you really wanna cut some more weight and can fab well, I think dropping the RWD transmission/axle and using an old 4sp FWD manual transmission connected to the motor in the rear (MR?) would shave off another one to two hundred pounds.


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## mjcrow (Jan 5, 2008)

Good engine weight resource here http://fixrambler.com/engineweightchart.txt

I'd love to do an 8 series beemer, but they are just soooooo heavy


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## electromet (Oct 20, 2009)

mjcrow,

That's a great link! I had visions of standing on my bathroom scale with an armful of engine and transmission to calculate my weight loss since my donor is not mobile. Thanks.


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## bluefxstc (Dec 29, 2007)

Great site Mjcrow, thanks


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