Crazy plan: A Tesla and chevy Volt powered EV hotrod S30

[primeral]

I've thought about the drivetrain from the RWD/AWD Lexus GS450h and LS600hL. We have a LS600hL and the power from the electric motor assisting the V8 5.0L is really nice, but I don't know how to feel about a CVT transmission in the Datsun. I suppose there won't be any gear shifting with a pure EV anyways.

[bawfuls]

Did you ever make progress on this? If so I'd love to see how you did it.  I did an EV conversion on an s30, but used a smaller motor which I mated to the stock transmission thus leaving the stock rear end unaltered. It was my first car project so I wanted to keep fabrication simple at the time. I'm thinking about upgrading though, and re-doing the car with different batteries and a small Tesla rear motor. Here's a mock up illustrating the fitment difficulty:

 

Another issue is vertical clearance, in order to avoid interference between the control arms and the motor, the motor will need to be high enough that it'll require some cutting of the trunk floor above it I believe. The distance from the underside of the trunk deck to the top of the control arm inboard mount is ~7.5 inches, while the small tesla motor requires about 10-11 inches of vertical space.

 

Edited April 4, 2021 by bawfuls

[grannyknot]

19 hours ago, bawfuls said:

Did you ever make progress on this? If so I'd love to see how you did it.  I did an EV conversion on an s30, but used a smaller motor which I mated to the stock transmission thus leaving the stock rear end unaltered. It was my first car project so I wanted to keep fabrication simple at the time. I'm thinking about upgrading though, and re-doing the car with different batteries and a small Tesla rear motor. Here's a mock up illustrating the fitment difficulty:

 

Another issue is vertical clearance, in order to avoid interference between the control arms and the motor, the motor will need to be high enough that it'll require some cutting of the trunk floor above it I believe. The distance from the underside of the trunk deck to the top of the control arm inboard mount is ~7.5 inches, while the small tesla motor requires about 10-11 inches of vertical space.

 

Did you ever do a build thread on the first EV conversion?  Let us know when you do the Tesla build. I haven't looked into very much yet but was also thinking about the next Z project being Tesla powered.  I guess the gear selection is all wires?  Mount all the batteries in the engine bay?

[bawfuls]

3 hours ago, grannyknot said:

Did you ever do a build thread on the first EV conversion?  Let us know when you do the Tesla build. I haven't looked into very much yet but was also thinking about the next Z project being Tesla powered.  I guess the gear selection is all wires?  Mount all the batteries in the engine bay?

I did a thread on another forum which you can read there, but not on HybridZ. The Tesla motors all have a single speed reduction gear (in the case of the small rear unit it's 9.34:1) so you select reverse by running the motor the other direction. The engine bay of the Z is pretty roomy for how small the car is, but you still have to select batteries carefully to get what you need into that space.

 

I'm kicking myself for not paying attention to this forum a couple years ago when the most recent 3D scan and CAD of the S30 was kicking around, it would be extremely useful for planning this build.

[clarkspeed]

Wow I just watched an episode of Car Fix on Motortrend TV. They were tearing down a Tesla Model 3 for transplant into a 60's Cougar. Motors, batteries, dash, and all. Amazing watching them take that thing apart and seeing all the subsystems. That battery pack alone is a engineering feat. Not for the the timid or inexperienced.  Electrical safety is a serious concern. I can see a future in electrification of vintages vehicles, it is so tempting to have that power/torque.  But motor swap from a Tesla would not be the easiest path!

[AydinZ71]

Beyond @clarkspeed‘s points, it would be great if someone could provide the complete weight of the powertrain and battery pack combo, including all cabling, modules, VFD’s etc. my experience would tell me that the weight is extensive. The weight difference between the entry-level model 3 and the long-range dual-motor version is nearly 500lbs. Completely different thought process to consider when comparing low-high HP ICE based cars. 
 

still a great idea and I’m sure it will be a killer Z if successful. 

[bawfuls]

No one can provide you with an all-in weight because it varies significantly depending on batteries, but here are some numbers for a bit of context. My Z uses a smaller motor which provides roughly equivalent power (but more torque) to the stock L28 and weighs 120 lbs. I used 5 Tesla Model S battery modules (less than half a full pack) which are excellent from an energy density standpoint (275lbs for 26kWh not including the battery enclosure). My car in total is 2450 lbs without driver, so I did actually drop some weight vs the stock setup.

 

I have a long spreadsheet comparing various potential battery modules for EV projects, and their weight varies substantially, from 10-30 lbs/kWh. The batteries I have are on the very low end of that range, but they only get me to a nominal 114V which is fine for the motor I have but wouldn't be suitable for a Tesla motor (needs 355V).

 

The higher power upgrade I've been looking at (swapping to a small Tesla motor for ~300hp/250 ft.lbs) would likely add some weight. The motor would be 200lbs instead of 120, though I'd drop the transmission, bell housing adapter, drive shaft, and differential while adding a new rear subframe to accommodate the motor. Batteries would be ~500lbs before enclosure so nearly double what I've got now, and I'd need a real radiator. I would guess it ends up a couple hundred pounds heavier, which imo is a fine tradeoff for the additional power.

 

The batteries are where most of the weight is in an EV conversion. Motor+inverter is next, but after that there is very little of significant mass.

 

Volt batteries btw are some of the heaviest (~28 lbs/kWh) and bulkiest, but they are the cheapest way to get a high voltage pack and they've got nice integrated cooling. A full Volt pack is 400lbs, 360V nominal, but only 14-17kWh. The guy who put a large Tesla motor in an E30 (@tesla_bimmer on IG) has two full Volt packs in parallel in it, they occupy the whole engine bay and trunk.

Edited April 26, 2021 by bawfuls