# First Post: Planning an EVM3 conversion (99' E36 M3)



## HupJai (Jun 11, 2019)

Hey y'all!

New to this forum but not my first online community, I'm excited to see what'll be contributed and what I can contribute myself. Get ready to read my life story!

I'm in the planning process of converting an E36 M3 to an EV. The car will be given to me from my cousin who received it from another cousin who bought it back in '99. The car is the M3 trim with an S52, stock suspension and plenty of rust bubbling on the body from living right off the San Francisco beach. 3 years ago, the car stopped running and has been sitting. I thought it would be a great candidate for a conversion!

My technical experience includes my fooling around with my own E36 (sold back in 2014 ), installing stereo equipment and replacing suspension components as well as fixing bicycles. This experience lead me to an Mechanical Engineering internship at an automation firm building industrial control panels. So I have some mechanical inclination, can read wiring diagrams, and use CAD software. With a few favors from my friends, I could access to machine tools.

With this conversion I'm hoping my range will be around 100 miles, I could probably live with 90 miles but I'd like to be able to drive this to work and charge once a week (or not, that;s cool too). As for performance, I really don't have much to ask for. Freeway speeds around 60 to 65 mph would suit me just fine, I usually average 40 mph on my commute. 

The budget would ideally be less than $10k USD. I'm willing to push that up t o $12k-15K after some preliminary calculations on how much batteries would cost at my range and knowing how "budgeting" works in real life, I feel like I'm looking at a $20k project. 

Parts considered after shallow research and recommendation by a friend, a warp 9 motor or Nissan Leaf motor. But anything can happen and my priorities for this project would be budget, completion, and practicality. Oh but I'd want it to look fast and not go fast but that's outside the scope of this project. 

I'll be poking around the Wiki and searching for previous E36 conversions for tips and designs (why reinvent the wheel?), looking forward to (and would appreciate) any input!


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## Tremelune (Dec 8, 2009)

Salvaged OEM components will likely offer you the best bang for buck. I'm partial to Nissan Leaf components because they're common, and you can get a whole running car for $5-6k. You might even get 100mi out of the batteries. There are some aftermarket controllers and what not available, though it's all pretty young.

The simplest approach is likely to keep the transmission and driveshaft. Both should be able to handle the torque, and it means you don't have to do crazy things to the chassis to get the Leaf motor in the rear or drive axles in the front. The tricky bit here is mating the Leaf motor to the BMW transmission with adapters precise enough that vibration is minimal at high RPM.

The Warp 9 has become a kind of standard such that it might be easier to find an adapter that already exists, but I find it hard to justify when a Leaf motor can be found for $500 pretty easily (210ftlb of torque, 10k rpm redline at 350-400V), though the Warp 9, AC50, HyPer9 et al can be made to work well at lower voltages (which can make battery sourcing/installing easier).

The rest is just figuring out where to put the various components...and a bunch of other things...

Here's my thread discussing the various approaches to repurposing Nissan Leaf components, with some trials and tribulations thrown in:

https://www.diyelectriccar.com/forums/showthread.php?t=199847


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