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14376 Views 70 Replies 15 Participants Last post by  mtrehy
I'm converting a 1969 Jaguar XJ6 to run with a Tesla P85 motor and 85kw battery pack. I want to drive it daily. I want it to look completely standard inside & out. I want to do a really classy/ professional job of the build with a similar comfort/ feel to a modern car. I have zero experience though so its a steep learning curve. photos below. Not my exact car but very similar.

My original plan was for a DC motor, powerglide and 30kw pack but I found a Tesla motor locally for little more than I would have spent on the DC motor so I grabbed it, same for the batteries. Its complicated the build somewhat but i'm enjoying (mostly) chewing on the problems and think its will be a classier, significantly more premium build when done.

I have the car, and have done a small amount of resto-modding. Removed the engine, welded up all the extra holes in the engine bay. It will get a coat of paint in time. I removed the front suspension and had it sandblasted and powder coated. I've upgraded the brakes and replaced every rubber bush with Nolathane and new ball joints too. I bought it thinking the paint was ok but on closer inspection it wasnt. I wish I hadnt spent as much on it, traps of old cars I guess. I added power windows and remote central locking. I'm trying to add AC which is as much of a challenge as anything. The car came with an aftermarket box under the glove box. I want the factory AC. I have nightmares about it fitting/ working/ breaking.

I had a range of rust to fix here and there, and there is a bit more to fix but if i fixed it all now i'd never get to the juicy bits. Leave the rest to the end.

I designed the battery boxes myself. When i pop the bonnet i want them to look clean and tidy. They had to be engineered to meet Australian standards, thankfully CAD has been useful in that regard.

The rear end will need to be redesigned entirely. The engineer didnt seem to worried about that so he has boosted my confidence. I'm thinking a trailing arm set up at this stage. Double wishbones could be tricky to fit around the motor.

As of today I'm in the process of bench testing the motor using the VCU. I also need to weld the battery mounting frame. Once those jobs are done, i'll eye off the motor mounting frame and invite the engineer to help design suspension. He has to sign it off at the end so working with him along the way makes my life easier. My quiet job is trying to devise a means for the VCU to drive the original guages. Im thinking of achieving this through an Arduino and stepper motors.

That'll do for now. more when i can find the photos i thought i had.


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14months, i thought it was worse.
For all my spare time i now have a lovely new bathroom and renovated part of my house. Now thats done, i can get back to this.

i have the battery boxes made and their mounting frames. You can see two of the three locations mocked up with cardboard boxes. I'm pretty excited to have a frunk. Although in Australia, it would be called a froot.

I'm close to a solution for AC, i found a great company that lists all the individual parts with dimensions and that has been incredible to have when retrofitting something that never had AC!

Today i mocked the motor up into position, you can see i've made a rough jig to hold the wheel hubs in place while i build everything around them. The engineer is coming in 4 days to discuss the rear suspension, i have something i think will work but it really needs his eye to review it, he's forgotten more than i'll ever know about suspension design.


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Awesome, looks great. Don’t forget to leave room in front of the engine compartment for the AC condenser. You might also want to make sure you box in the frame where the old radiator support was.

Can’t wait to see this thing running. How many Tesla modules are you running again?
Some good progress recently. I’ve found a rear suspension solution and worked towards it and got some more parts and solved some future brake problems.

The engineer changed my rear suspension design to be harder to make but stronger. I was hoping for a sexy space frame rear setup but he encouraged me to look for OEM parts I could adapt to fit. I found a tutor to walk me through autocad to design the parts but stumbled across another solution. I found out the tesla I have parts for uses 120x5 pcd similar to my jaguar. For shits and giggles I put the rear tesla hubs in my hub jig and with the motor roughly in place found the upper and lower control arms actually fit really well. Using the complete Tesla rear hub, brakes and control arms will save a lot of time and money, both of which I can better spend elsewhere.
That makes a new problem that I either modify the rear brakes to be smaller (originally 355mm, Jag rotors are 280mm) or modify the front (which are 280mm). Seems stupid to downgrade brakes so I think I’ll put Tesla brakes on the front, 355mm rotors (which almost fit) and use an adapter to fit the tesla caliper. I think that will look good, I’m already using the Tesla brake booster so basically a whole system swap which is helpful for brake bias issues too. Briefly look at stand alone ABS (since the rears already have the hardware but quicly shelved the idea… well maybe in the future).

This weekend I’ve made a ridiculous jig to align the wheel hubs and motor and copy the Tesla suspension mounting points to be able to translate them to the Jag. Its taken two weeks of brainstorming to make a workable design and another several hours to build. The suspension mounts need to be able to move inward to accommodate the smaller track width of the jag, as well as being able to move down because the jag is lower. The motor also needs to move up, I’ve raised it to improve clearance as directed by the engineer. I’m working on this build being really high quality so even though it’s a temporary jog, I paid a lot of attention to detail. I hope it pays off. I even added adjustable bolts so I can level the jig in two axis. The cars have also been levelled. Photos are of the completed ‘negative’ jig that fits within the chassis side suspension mounts. I need to add a ‘positive’ jig to locate it in the jag based on the control arms attached to the hubs in the hub jig.

@Bryson, Thanks for the tip, actually the lower radiator mount was dented when i got the car, i remade it from scratch with thicker steel. for batteries I’ll be using 16 tesla modules for a standard 400v Tesla battery pack. I’ve also got a Tesla charger I’ll hack with a Zero EV board. I got a bunch of coolant pumps, a radiator and condenser that may be too big but were free and a Astra power steering pump that I thought about swapping for electrically assisted steering but not convinced I want to. Would like to for efficiency but want to stay to keep road feel and I have the pump already… open to ideas.


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You're a mad man, nice progress. Two questions:
1) how much wider is the Tesla track than the jag track?
2) have you fit the Tesla brake booster yet? Keeping the original pedal linkage? How did you adapt them together if so? I have one in the garage that I’d like to install eventually as well but it’s low priority.
Thanks Bryson,
Jag wheel track is 146cm tesla is 168cm.
I'll take a photo of the brake booster. I've used the original jag brake pedal and linkage. The jag brake booster bolted to an aluminium box that housed the brake pedal pivot.
Your options are to use an adaptor plate in the range of 15mm to bolt them to each other or cut the pushrod shorter in the Tesla brake booster. I've opted for the latter because in either case you'll need to cut a relief in the inner wheel arch and i wanted to minimise any intrusion into that space. Some modest die grinder action on the aluminium box clears enough space for some nuts.
Awesome. Did you try flipping the booster to see if it fit upside down without cutting the wheel well? It should work in either orientation. I haven’t gotten to the point of that yet as my vacuum pump works just fine. The Tesla booster is ‘cleaner’ however 🙂
I recall thinking about it but didn't. My photos suggest it may work so now I don't know what I was thinking.


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In the first photo it looks like the master cylinder cap may hit the bonnet?
Thanks Blwnhr that's probably why i did it this way. I've checked and it clears the bonnet by 1cm or so.
Buildmore; when i received your message i was actually looking at an XJ coupe to buy. I really wanted it, but it was very rusty and i just couldnt take such a big step back now i've done so much work on the sedan. :/

Brian; yes it was tempting to get the whole setup but one regulation here in order to get the car registered is that you cant widen the car more than two inches. Tesla is much wider than the jag unfortunately.

I've been grinding away at this but not as much as i would like. I've been wiring up the motor. That is damn scary i'm so afraid i'll connect something incorrectly. I am using an advantics VCU and that has bee difficult too. I expected the board to be sent back frmo them ready to spin the motor but i need to know how to do computer programming and work with CAN and i know neither. this wasnt made clear at the outset otherwise i may have chosen a different method. THe manual has limited information which doesnt help because everytime i take a step forward, i find out i need to get a piece of hardware or knowledge that takes me weeks if not longer to learn/ get. I could not recommend the advantics vcu to anyone unless you know how to computer program and have played with CAN before. Its not a skill that comes naturally too me so that complicates things. Michal has been working ok with me, i just wish he was more helpful given how little i know. If i ask something he doesnt want to answer, he just wont answer. for example i've asked he confirm the wiring of relays, recommend a program to work with CAN, asked if i can use arduino and CAN shield instead of arduino due, no response.

Last night i was working on it. I had made good progress but in the process blew up my contactors. I was testing the VCU's control of the contactors. I should have disconnected the HV wires but didnt. blew up both positive and negative contactors. bummer.

These few months has been an exercise in persistence and motivation. Balancing my time between physical results, like i've been welding a battery mounting frame, and the wiring stuff, has been helpful.

I have time off next week to keep building the battery frame. Will have to wait a few weeks to get some more contactors.
Wow, what project. I have been introduced to using the advantics VCU as well. Who is Michal? did he sell you the VCU?
I have a million questions. Are you willing to answer some? Lets start with Michal. Best Regards, Randall
Hi Earz,
sure, i'll try to help. Michal is the guy who designed the board at advantics, he sold me the VCU
Did you ever connect to the VCU with a computer? did you use Uniflash from texas instruments?

Did you complete this build? Would be interested to see where you ended up with the rear suspension and tesla drive...

Did you ever connect to the VCU with a computer? did you use Uniflash from texas instruments?
Yes and yes. I have no computer or electronics skills. I did it, it was very challenging.

It's not finished yet. I'm trialling using the original tesla control arms and drive shafts and building a narrower subframe to mount it all. It sits too close to the ground currently. I want to double check I've set it up correctly and may move it around.
Did you make any progress with the custom subframe? I'm working through a similar concept and would love to see any of your measurements for where the suspension mounting points are relative to the motor mounting points in the stock Tesla subframe.
not sure if you seen Roadstercycle build called Tesla Motor Swap Mustang GT Part 1 where he mates a Tesla motor into a modern Mustang GT, maybe it can give you some ideas, just trying to help
Thanks @gregski. I just watched that series recently. It was very cool, but unfortunately doesn't help with my project. He uses the complete Tesla subframe and I'm trying to narrow the track width significantly.
Thanks @gregski. I just watched that series recently. It was very cool, but unfortunately doesn't help with my project. He uses the complete Tesla subframe and I'm trying to narrow the track width significantly.
I've got the tesla LDU and rear track of just 55" but it is completely custom design suspension, wishbones, uprights etc.
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I've got the tesla LDU and rear track of just 55" but it is completely custom design suspension, wishbones, uprights etc.

Any chance of some pictures, mtrehy?
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