I spent some time today figuring out where the electric motor is going to go. This is unfortunately a prerequisite before I can figure out where and how big the battery can be--it doesn't make sense to plan batteries only to find out that the motor is occupying your entire volume!
I'd like to, as much as it is possible, put the electric motor directly where the differential of the RX-8 was, which may involve some rear subframe stuff. I have the part drawings and some measurements, but what I really need to bring everything together is a detailed 3d model of the subframe. Someone has scanned their NC (gen-3) MX-5 subframes and put them online, and I was hoping that they'd be equivalent (there are various forum postings for and against). I did some digging, and while the rear subframe is /extremely/ similar, to the point of being bolt-on compatible, it's not 100% identical to the RX-8 rear subframe.
Thankfully, Andrew from Keisler Automation is super friendly, and sent me a copy of his 3d scanned RX-8 rear. Keisler sells bits and complete kits to swap a GM LFX V6 into an RX-8, and I noticed on their web store front for their rear differential kit something that looked like a 3d scan, so I asked nicely :)
It looks like the Tesla Small Drive unit wouldn't fit without quite a lot of modification, both to the subframe and the bodywork of the car. It'd also stick out the bottom, which is no bueno. The model 3 rear drive unit, however, seems to be possible and even reasonable.
