[DRIVING] 1940 Chevrolet with Tesla Motor

[P.S.Mangelsdorf]

So in good news, the IGBTs are actually fine. All 3 stages test fine on a diode test, and visually look fine. I did have coolant in the inverter, I think from a leak above. After cleaning the OI board connections repeatedly, I am still seeing an instant OC error upon sending a start signal. I think that the coolant must have shorted something on a gate driver board, but diagnosing and repairing that is pushing the limits of my knowledge. My plan now is to do a bit of research/planning this week, and if I can't figure out how to properly test/repair the gate drivers, then I'll part out the base unit to repair the waiting Sport unit, and just get the swap over with.

[P.S.Mangelsdorf]

From powering it up this weekend, I discovered one phase is showing a fault, likely a bad gate driver, so the base LDU is coming out. I also discovered coolant in the encoder, so that unit needs a full rebuild. I need to do some repair and maintenance on the Sport LDU before it goes in, and may have to steal some parts off the base unit.

[Bratitude]

These old ldu seem to be fairly problematic! The power tho…

[P.S.Mangelsdorf]

These old ldu seem to be fairly problematic! The power tho…

Yeah that's the catch-22 - great power for relatively cheap (thanks to Damien and his OI board design), but with the longevity problems of a product designed by Tesla.

I'm really hoping Lucid succeeds, just so we can get our hands on their drive units. Similar or greater power, but half the weight? Sign me up!

Long term, if the LDU continues to be the go-to for performance EV builds, I can see a world where improved versions are available new the same way you can buy new cast or billet small block Chevys from Dart, Blueprint, and others. There's probably a market for a conversion version now, and I think there could be a market for a stock replacement version in the future. I think that if someone could sort out the code side, there's also probably a market for a higher performance bolt-in inverter upgrade for stock cars, but the code aspect is a major stumbling block. Its a brand new world and there will be new Offenhausers, Edelbrocks, Holleys, Weiands, Keith Blacks, Sonny Lenords, etc born out of it.

Coming back to the present for a bit - the LDUs are proving to need much more monitoring than expected. But frankly, we should expect it. It's essentially the first generation of modern EV propulsion units, and its over 10 years old. Achilles' heels should be expected at this point. Now its time to figure out how to solve them or work around them. And we as a community should probably start figuring out what unit will become the small block Chevy to the flathead Ford that is the LDU.
(For those not versed in hot rod history, the flathead Ford was king of the first generation of hot rods, but was dethroned in the late 50s/early 60s by the SBC)

[P.S.Mangelsdorf]

Well the Base unit is fighting just about as hard as it can to avoid me installing the Sport unit.

I got it out of the car relatively easily, though I did realize halfway through that I needed to raise the car another 3 notches on the jack stands to get my hydraulic table under the front of the unit. Then began the issues.

The adapter plates do not want to come out of the unit. No amount of pry bars or slide hammers, or swearing would get them to move. Even managed to pinch my hand in the slide hammer, that was real fun. Saturday, I did some Google-ing, and the only solution I hadn't yet tried was an axle popper fork (actual name) so I found one Amazon said they could overnight to me, arriving before 11am on Easter Sunday. Fantastic! Except its now Monday and I still have not gotten it. Less fantastic!

On the Sport unit there's better news. I opened up the gear box andddddddd its fine. No broken gears, fairly clean oil, I've got no idea why this unit was pulled. Unfortunately, while reassembling, I managed to snap the very last bolt I tightened. Of course it was one that could not be reached with any tools unless the unit was disassembled again. So I did that yesterday, got the bolt out, and replaced it with one off the base unit.

I also removed the inverter from the base unit, partially out of curiosity, partially to facilitate its eventual repair, and partially to keep it protected. In doing so, I don't see clear signs of coolant entering from the motor bus bars, so I wonder if part of the inverter cooling cracked when the unit was ripped out of the car at the end of DW. I need to do more investigation there.

Long story short: If I can get the damn adapter plates out of the base unit, I can get the sport one in the car and hopefully driving again in short order. Hopefully.

[P.S.Mangelsdorf]

Small update:

I didn't have much time to work on the car this weekend, but I did get to do a few things.

The adapters remain in the base unit - I'm very close to just buying replacements, but I'm trying to avoid that.

I did a very brief test spin of the Sport unit, and it spun up perfectly fine. I'm excited to get it in the car, but I think I'm going to go ahead and do the LSD install now, so I don't have to fight axle adapters again in the future.

[P.S.Mangelsdorf]

Finally some positive updates!

I have a new set of adapters on the way from AmpRevolt; huge thanks to Brandon for helping out with getting those.

I have finished installing a limited slip conversion kit from Traction Concepts. This uses the stock open diff and adds limited slip components. It took longer to prep and install than I thought it would, but I'm happy with the fitment. Looking forward to testing it soon.

I also installed a rotor coolant delete kit from EV Muscle Cars (aka Kevin Erikson, aka Electrolite guy). Rather than the full billet pieces from Revolt or QC Charge, this modifies the existing coolant manifold to eliminate the rotor cooling and then block off the rotor cooling passageways. It includes a nice TIG welded hose barb/flange, and 3D printed block off pieces.

As you can probably gather, I'm trying to find the most cost effective (read: cheap) ways to get the car back and the road but also improve it.

I have some suspension fixes/updates also on their way, so the hope is the car will be back on the road next weekend, and back at the track later this month. I'm really hoping to get some track testing done before I talk about the car at SOC24.

[johu]

I'm reading a lot about coolant delete. Does it mean rotor cooling was over engineering practise in the first place?

[P.S.Mangelsdorf]

Does it mean rotor cooling was over engineering practise in the first place?

To be frank, I don't know. I am mildly concerned deleting rotor cooling could be an issue, but I'm also not willing to let a coolant leak take the car off the road again.

Here's what I was able to figure out:

• Replacement seals are hit or miss, and one of the more common options would limit the speed to around 100mph, which is a problem for racing.

• It appears Tesla did develop a coolant delete manifold themselves for the -U revision drive units and later.

• I can find no evidence of Tesla's delete manifold in the wild. It appears on a parts list and one or two service photos, but I can find no reports from Model S owners with a delete manifold. There's also no word on whether those drive units were derated in any way

• It does appear that those running the aftermarket/DIY delete manifold are not seeing noticeable issues from deleting rotor cooling.

• One of the billet options does maintain cooling via oil and a heat exchanger, but in my opinion that doesn't do enough on the inverter failure problem. I have also seen an option to modify the inverter housing with a drain, which really seems like a ridiculous approach.

I think over the next 6-18 months, we should know pretty definitively whether rotor cooling was necessary. I'm going on Drag Week again in September; if it survives that, I think it'll be safe to say the rotor cooling was overkill.

[P.S.Mangelsdorf]

I was very hopeful I could have the car back together this weekend, but did not succeed.

On the to-do list were two tasks: Install new rear control arm bushings and install the drive unit.

The control arm bushings were to address an issue with excessive camber in the rear, a problem on the GTO suspension I am using. Getting the bushings out was a fight, and finding just the right position to get them in was also a fight. In the process, I had to disconnect the tie rods, and during reassembly they have fought me. On one side, it was close enough to force the bolt in, but the other is just slightly far enough that I need to loosen the tie rod, install, and then readjust. Unfortunately, it does not want to loosen. So it's sitting with penetrating oil, and I'm hoping to get it free this week.

[johu]

Old cars... Where mine is just 20 years old. Camber can no longer be adjusted because the eccentric bolt has become one with the subframe. So sooner or later I'll just swap the entire rear axle

[P.S.Mangelsdorf]

While I have some time this week, I'm trying to finish up plans for the next set of upgrades: charging, both Level 2 and DC fast.

I'm going to keep my CHAdeMO plug, and add CCS to my J1772 plug.
I also need to replace my Model 3 PCS with something that will function reliably.

I've been working on laying out and pricing options, as money is tight but these upgrades on necessary for Drag Week in September. The two options I've been considering are:

1) Leaf PDM, Zombieverter control, i3 LIM for CCS
2) FOCCI for CCS, TC Chargers 6.6kW charger+DC-DC

I would really prefer FOCCI, as it seems to have the best support right now, but that option appears to be more expensive by a couple hundred dollars, mostly on account of the TC Charger. On the other side, the i3 LIM and Leaf PDM are not the easiest things to find, especially as most junkyards don't really know what they have, and so list them in all sorts of different ways.

So I have this question for anyone that cares to chime in: What options are there for a OBC (ideally with DC-DC too, but without is ok) that can provide at least 6.5kW, for a battery that is just under 400V at full charge, is fairly cheap, is available in North America, and the CAN control messages are known?

[P.S.Mangelsdorf]

So I have this question for anyone that cares to chime in: What options are there for a OBC (ideally with DC-DC too, but without is ok) that can provide at least 6.5kW, for a battery that is just under 400V at full charge, is fairly cheap, is available in North America, and the CAN control messages are known?

Well I might have answered my own question.

From this thread on DIY EV https://www.diyelectriccar.com/threads/ ... ct.209589/ I learned that SOME 2019 Chevy Volts came with a 7.2kW OBC, and it appears to be controlled the exact same as the 3.6kW unit, which arber has already reverse engineered here: viewtopic.php?t=1690 Well that looks like it could be an option, now only to find one....

Well in my digging around on ebay and various Googling, the Bolt OBC looks veerrrrrryyyyyy similar to the 7.2kW version of the Volt charger (which is clearly different physically from the 3.6kW version) I wonder if it can also be controlled with PWM? I may have to pick one up and see.

(as a related sidebar: why, GM, must you change part numbers over and over and over again? Makes tracking down parts a PITA)

[ScythianNite]

The 7.2kw charger from the jeep plug in hybrids looks like it could be an interesting option too, though it hasn't been cracked yet AFAIK. Its long and narrow and has built-in dcdc.

[johu]

Other options would be Model S OBC, dual Outlander OBC or SAIC (MG ZS) OBC that Damien hacked lately. But since yanks are cracking down on Chinesium the latter might be rare

You could hack Foccci to produce the necessary CAN messages as they aren't very complex

[P.S.Mangelsdorf]

The 7.2kw charger from the jeep plug in hybrids looks like it could be an interesting option too, though it hasn't been cracked yet AFAIK

I'm interested in cracking the 4xe stuff, but I'm not sure this is the project to do it. I'll have to poke around and see if there's any CAN logs out there yet.

dual Outlander OBC

Good point. I could also do dual Volt Gen1s, those are pretty easy for me to get my hands on.

yanks are cracking down on Chinesium

Yeah getting one of those is unlikely.

You could hack Foccci to produce the necessary CAN messages as they aren't very complex

The interesting thing with the Volt Gen2 (and maybe Bolt) is that they're controlled with just PWM. Are there any unused PWM capable pins on FOCCI? Otherwise a simple Arduino sketch to get the voltage from CAN and the available power from the pilot and then output the needed PWM to the charger seems easy and cheap for me to put together. I should remember enough code from college to create that.

[P.S.Mangelsdorf]

Well I was really hoping to be posting this evening about driving the car for the first time in months, and how great the Sport LDU is, and how I'm taking it to cars and coffee in the morning. But alas, the car continues to fight me.

When I bought the sport LDU last summer, I was told it was pulled from the guy's Model S because something failed in the gear box. He could hear the motor trying to turn but no forward motion. So when I went to put it in the car this spring, I opened the gear box, found no gear damage, then tested with just a axle stub, and everything turned, so I went ahead with installing the LSD and coolant delete, and then installing the unit in the car. Today, after finishing the install, I went to drive it, and the motor spun but the car didn't move. Clearly the test with the axle stub was not enough load to show the damage.

After removing it from the car and tearing down the gear box completely this time, I found what I'd feared - the splines on the rotor shaft and its accompanying gear have stripped.

Fortunately, I have the old base unit sitting in the garage half torn apart. Unfortunately, the old adapter plates are still stuck in it, so I can't get into the case. I'm not going to just swap the sport inverter into the base LDU, because the base case has some damage, the thermistor wires are damaged, and I really want the LSD.

My tentative plan (which I am going to sleep on and decide in the morning) is that I will cut one of the old adapters in half so that I can open the base case, then take the first gear and rotor out of the base, and install them in the sport. Then put everything back together and back into the car. I don't like the idea of destroying the adapter, but I've run out of ways to try to remove them, and the parts I need to fix the new unit are sitting right there - buying new parts would be ridiculous.


In better news, I did find a Bolt charger for an utter song on Ebay, and it should arrive here Monday. Assuming that I get the car drivable, then I will begin testing on the Bolt charger. When I do, I'll start a new thread for reverse engineering that charger. It may be delayed a bit as I have to travel for a family event next weekend, but I may have some gaps in real world work this week that would allow me to go test during the week. I also remembered that a good car friend locally has a Bolt, so if the Volt Gen2 controls don't work, I can probably cajole him into letting me data log or at least investigate using his car.

[P.S.Mangelsdorf]

Quick update:

Made good progress on building the Franken-driveunit. Have the rotor with good splines into the Sport unit, still working on getting into the bad gear box to grab the first gear. Interesting differences between the two rotors, will share more later.

Also good news on the Bolt charger. It arrived yesterday, and today I paid for 3 days access to the GM service manuals. Confirmed that the pinout is the same as Volt Gen2 for the control, and also that the control and battery connectors are the same. Unfortunately, the AC connector is different. After a lot of searching around, I figured out it is Aptiv part # 35197127. Which appears to not be readily available, unless you want hundreds of units. I'll figure out a way to test without it, and will likely pick up a Bolt CCS port to get the connector and a CCS port for use with FOCCI.

More details to come.

[P.S.Mangelsdorf]

More detail on the above posts:

Here's what the rotor shaft of the Sport drive unit looked like:

And the shaft of the Base rotor, in much better shape.

The Base clearly had a coolant leak for longer than I thought. It cleaned up pretty quickly with sand paper and a kitchen scrubbing pad.

The Sport rotor was in much better shape (apart from the stripped shaft.

Two comparisons of the two rotors. In my mildly educated opinion, the differences represent design updates more than a Sport vs Base difference. The center section of the rotors appear identical, the ends are different. The Sport moves the mass to the outside, allowing easier access for a bearing puller (I had to modify my puller to get it behind the bearing on the Base rotor).

I am still working on cutting through the old adapters on the base unit so that I can open the case and get to the gear I need. I'm also not entirely sure the rotor bearing seated correctly when I installed the base rotor into the Sport case. Not a bearing or case issue, just a factor of me rushing. I'll check that before I finish putting things together. Speaking of bearings, both rotors had less than good encoder-end bearings, so I pulled the gearbox-end bearing from the Sport rotor and put it on the Base rotor encoder-end. This will be truly a Dr. Frankenstein's monster of a drive unit, but it will get me back on the road (I hope).

I am wondering if there is any way to swap the shafts between the rotors, but I have so much to do on the car and so little time that slapping it back together is going to have to be enough.

[muehlpower]

I think you're right. the rotor on my sport unit looks like your base.

[P.S.Mangelsdorf]

the rotor on my sport unit looks like your base.

Good to know!

[P.S.Mangelsdorf]

It's Alive!!!!!!!!!!!!!!

Only took a short trip around the neighborhood yesterday to confirm everything is working after rebuilding the entire gearbox. Basically at this point I have removed and reinstalled almost every single part in this drive unit.

I'm very much looking forward to working on the tune to take advantage of the sport inverter. Unfortunately, we are expecting heavy thunderstorms today, so that may have to wait.

I did film a lot of these upgrades, and I'm planning on putting together some Youtube videos of the process.

[P.S.Mangelsdorf]

This !@#$%^&*&^%$#@ [Insert many creative swear words here, and remember I'm originally from New York] @#$%^&*()(*&^%$#@! car has once again found a new and creative way to break.

In this case, part L1 on the control board, the inductor on the 12V supply, broke off while driving. Since the board lost power, the contactors opened and damaged the BRAND !@#$%^&^% NEW !@#$%^&^%$#@ SPORT INVERTER!!! All I wanted to do was show off my fun car at the gym on July 4th, but no, I had to have a friend unceremoniously drag it home with a tow strap.

Part of my frustration (mind you, this is after 24 hrs to cool off) is that I noticed it was a tiny bit loose when assembling the drive unit, but it seemed to be fairly well attached. Apparently I was wrong, and now a $0.50 part has cost me another !@#$%^&*(^%$# inverter.

I plan this weekend to pull the inverter and figure out the part # and how many IGBTs I need to order, and put in one order with those and the inductor. I'm hoping that I can do this fix and get the car back running. I don't have the money to buy another inverter.

This will obviously delay my Bolt charger reverse engineering, despite parts showing up for that task today. Still need to have the Bolt charger (and DC-DC too) figured out, installed in the car, and add CCS before September for Drag Week. I did pay for a few days of access to technical manuals so now I have real wiring diagrams and some part numbers.

(EDIT to add: If unclear from the above, I'm both immensely pissed off and pretty heartbroken about this turn of events. I just want to drive my car.)

[johu]

Holy crap, that sucks.
is it an older board with the large 8x8mm inductor or the newer with a 1206 one?

[P.S.Mangelsdorf]

is it an older board with the large 8x8mm inductor

Yeah its v4b