[DRIVING] 1940 Chevrolet with Tesla Motor

[P.S.Mangelsdorf]

Oh no, what's happening with the charger (Dodge) ?

Short version: on Tuesday it was towed into the dealer for failure to start. It's still there.

Long version: There appears to be a significant issue with the Charger Daytona (and presumably the whole STLA Large platform) regarding the 12V system. Several owners, including myself, have had issues with the car refusing to start with a "service EV system" error. It often resolves itself by waiting a bit and trying again, and occasionally by charging the 12V. In the past few weeks its gotten noticeably worse. On Tuesday mine wouldn't start and none of the tricks worked.

According to a Mopar tech on the Daytona forum, what he has been told by Stellantis engineers is that, (caveat here that this in now 3rd hand info), basically when the 12V battery voltage drops even a little bit the DTC that it throws tells the car to open the HV contactors. Which obviously then prevents the DC-DC from charging the 12V battery. Which then causes a cascade of other errors.

[barracuda816]

Wow, that's hell of a programming oversight. But hopefully an easy (and quick update fix for you.

[P.S.Mangelsdorf]

But hopefully an easy (and quick update fix for you.

So far its not looking that way. Stellantis seems to have the most bass-ackward system of communicating with the dealer tech's, and they also seem to not have an update ready for this issue.

I don't know if this is a result of legacy code/hardware, or some engineer convinced this was a smart idea, or just big-organization inertia, but they don't seem to have a real fix. Its also still there with no news other than "the tech is talking with Stellantis"

[P.S.Mangelsdorf]

Got the inverter swap done last night. Left the drive unit in the car and just dropped the suspension enough to pull the inverter out, which can be a bit of a pain but is less of a pain than dropping the whole drive unit.

Only had time for a quick drive down the street to make sure everything worked, hoping to do some tuning this week and maybe a track test next weekend.

[dbc105]

Paul, when you built this car did you weld the rear sub frame in or is it mounted on the rubber bushings? I was thinking about using your same suspension swap on some GMs with a 4-link. Thanks

[P.S.Mangelsdorf]

Paul, when you built this car did you weld the rear sub frame in or is it mounted on the rubber bushings? I was thinking about using your same suspension swap on some GMs with a 4-link. Thanks

The forward two bushings are in place, the middle point is bolted to the car's frame.

However, I don't recommend using this solution. The subframe prevents the drive unit from getting as high up in the car as it should be, leading to weird axle angles and the combination of a tall ride height and low hanging drive unit. Also, the GTO rear suspension is known to have camber issues (and no real adjustment) and I have had issues with that.

A better approach might be using the GTO hubs and trailing arms with custom mounts, rather than trying to use the subframe like I did.

If I was to build this car over again, I'd probably go with a de Dion style axle. In fact, I'm working on designing one for the next race car, which I'll be pairing with a parallel 4 link.

[P.S.Mangelsdorf]

I started out yesterday with Shocking Chevy nearly giving me a heart attack. I wanted to go test, but needed to charge first, so I plugged the car in a decided to work on other small things that needed fixing, like the dented rear corner and taillight, trunk seal, etc. Once it was charged, I got set up for tuning (and videoing the tuning), saved the existing parameter set, and went to leave to go to my test spot... and as soon as I engaged forward, it tripped the Overcurrent-that's-actually-the-Tesla-gate-drivers-throwing-a-fit error, which is when it throws overcurrent and giving a start signal again doesn't clear it. So, despite having driven into the garage last weekend, I assumed something was up with the inverter. I opened up the case, plugged the low voltage harness back in, powered up, and no error lights. Hmmm time for danger - I connected the HV without the case on, and powered up the inverter, expecting to see an error light on a gate driver and... no errors. I gave it throttle, and it spun. Weird. I put it back together, half expecting it would not start, but it started fine several times, and I have no clue what cause the original error.

So I proceeded to my testing spot, a semi-private-ish access road that's straight and away from traffic and of questionable ownership (created when a new highway was built to provide access to a couple of farm fields, not clear if the state or the farms own it) and began testing. Now for context, my old "street" tune did a 3.47sec 0-60mph pull at this spot, according to my Speedhut GPS speedometer. I began by dropping fweak to where it was in best prior race tune, and then began raising fslipmax, from 2.6xx all the way to 3.3, at which point the battery had drained enough (about 85% indicated, 75% real world) that I wanted to stop and try this current tune again at full battery strength (the Volt batteries have a linear decay) to make sure nothing trips. Best time of the day 2.64sec 0-60mph.

I had been planning all week that I would go to a test-and-tune at Rockingham Dragway today, but it's currently pouring rain, so that'll have to wait. I really need to do some track testing to have the incrementals and see what these changes are doing at various points in a run. Also looking back at the video from outside the car, I definitely have some more suspension tuning to do.

Video coming, hopefully next by next weekend.

[johu]

2.64sec 0-60mph.

That is insane! Is it sport inverter all the way now?

[muehlpower]

2.64sec 0-60mph.

I really need your parameters
How heavy is your car?

[P.S.Mangelsdorf]

That is insane! Is it sport inverter all the way now?

Basically yes. Its all Sport phases, but the current sensors and a few other small bits are actually from the Base inverter because a) I didn't want to dig through bins to find the ones off the Sport inverter, and b) the base version appears to be a later revision. The casing is also originally a Sport casing, but it has the rotor from the Base version because of the stripped shaft on the Sport one, and it appears they were the same anyways. So the parts that make a Sport LDU into a Sport LDU (power stages) are all Sport now. The rest is a mixed bag.

[P.S.Mangelsdorf]

I really need your parameters
How heavy is your car?

Let me a do a bit more tweaking, then I'll share.

On Drag Week last year it weighed with me in it, 3510 lbs (1592kg).

[P.S.Mangelsdorf]

Wanted to test this weekend but the damn inverter is being weird again. Of course, just a couple weeks before the first event I've committed to this year. Started a thread about it here: viewtopic.php?p=83003#p83003

If anyone has ideas, I'd appreciate it.

[dbc105]

The forward two bushings are in place, the middle point is bolted to the car's frame.

However, I don't recommend using this solution. The subframe prevents the drive unit from getting as high up in the car as it should be, leading to weird axle angles and the combination of a tall ride height and low hanging drive unit. Also, the GTO rear suspension is known to have camber issues (and no real adjustment) and I have had issues with that.

A better approach might be using the GTO hubs and trailing arms with custom mounts, rather than trying to use the subframe like I did.

If I was to build this car over again, I'd probably go with a de Dion style axle. In fact, I'm working on designing one for the next race car, which I'll be pairing with a parallel 4 link.

Thanks Paul, glad you expanded on that because I would not have know to ask about subframe blocking the motor. I really like the DeDion axle idea, I 1st saw that with Jonny 5 and then on This Old Jalopy but he ran into interference with the car frame rails so that is to be considered there. The 4 link sounds like a good idea, I know a street rod builder that uses those kits and he really likes it, universal and tunable. Looking forward to seeing the next build.

[muehlpower]

I'd probably go with a de Dion style axle

I like DeDion, I have also installed it, together with air springs and a triangulated four link.
viewtopic.php?p=15994#p15994

[P.S.Mangelsdorf]

Spent yesterday trouble shooting the drive unit. No solution yet, more testing to be done today.

[P.S.Mangelsdorf]

Had the car working, then it stopped. I've officially withdrawn from Sick Summer, and plan to spend some of that time working on the car. Did decide to buy more parts, (because the parts-cannon solves everything, right?), but hoping that I can figure out the issue ahead of time.

[P.S.Mangelsdorf]

After changing literally everything in the inverter, I finally realized it was a problem with the OI control board, likely some connector issue. After a small comedy of errs, I finally got a new v6 OI board from Westside EV installed earlier this week, and the car now consistently starts. I'll be back to tuning (and possibly racing) this weekend.

[P.S.Mangelsdorf]

Oh, yeah, we're back.



Did a little bit of tuning yesterday. Mostly checking that my previous Sport tuning worked at full charge. It did. It's really interesting how much more room there is in the tune with the Sport inverter. For example, with the Base my fslipmax topped out around 2.6 before hitting the phase desat shutdown, but I'm already up to 3.3 with the Sport inverter. There's definitely still room to push some more power out of it, but I want to get to a track to see the incrementals. Unfortunately, the test-n-tune/race I wanted to go to last night was canceled due to heat. For reference, it was 99 degrees F (37.2 degrees C) yesterday evening, with humidity rising from 60% to 80%+

Now, with just over a month until Drag Week and a running car, I SHOULD just focus on tuning and tweaking, but I'm considering tearing apart the front end to change the front spring setup and finally finish the battery cooling/heating setup. We'll see, this heat really makes it difficult to want to go work in the shop.

In other semi-related news, my fleet is back up to one gas vehicle, as I made a deal yesterday to buy a 2009 GMC Yukon XL 2500 which will be my tow pig. For reference, that's a GMC version of the Suburban, but on a heavy-duty truck chassis. It's an absolute behemoth of a vehicle. The seller has to work out some title stuff before I can pick it up, but once I do, let the car and parts hoarding begin!

[P.S.Mangelsdorf]

I finally ordered and received a bunch of little parts for the '40 to wrap up things I've been neglecting, so I'm hoping to get those installed this weekend. Including proper window tracks/felt and replacement taillight lenses, since one got cracked on the way home from DW 2023 when it shifted slightly on the trailer and hit a folded up ramp. Also hoping to get to the battery thermal situation, and plan the front suspension changes. The weather should be nice this weekend so I've got all that plus yard work to do.

I did acquire my new tow pig yesterday and register it this morning, and it needs work too. At least a transmission fluid change, possibly a rebuild, and a rear cross member to replace. Plus it needs HEAVY cleaning and some electrical clean up. Hoping to do the transmission fluid and cleaning this weekend, and then maybe some work on the crossmember.

[P.S.Mangelsdorf]

Well good news and bad.

For the '40, mostly good news - I got the window tracks installed, which greatly reduced the noise inside, and this morning took it to both cars and coffee and the new Ionna charging station near my house. Ran well, no issues.

The rest of life, not so great news. My dog found 3 different ways to injure herself in less than a week, and we're waiting on test results for one of those problems still. This all occurred just after my new tow pig's transmission went out, completely. So, I have to get the dog healthy, then do a transmission rebuild, then get to Drag Week.

Looks like the suspension upgrade will not be happening, but I still might get the battery thermal management fixed, maybe. At least the car is running well right now, and I don't have any major work to be done on it in the month left to Drag Week.

I also picked up a cheap refurbished laptop that will be my new "tuning and data" laptop, rather than bring my nice laptop on races/roadtrips. I specifically got a 2-in-1 that can flip into a tablet so that I can (hopefully) have a mount for it in the car and have it data log via the web interface during a run. The idea would be I could start the data log after the burnout and stop it on the return road, so I just have the run's data.

[P.S.Mangelsdorf]

My Drag Week video is up! Check it out here:

[P.S.Mangelsdorf]

So, What's Next?

I've been thinking a lot about what is next for Shocking Chevy, for me, and for EV drag-and-drive racing in general.

Going into Drag Week, I had a tune that that I thought was very close to getting into the 10s. My goals included running in the 10s, with the hope that a sub-11 average might make the 32 car SME field. I could not have guessed that the bump spot would end up sub-10.5. I also did not anticipate this tune having such issues on track.

My plan before the week had been, if I managed to get into the 10s, this would likely be the car's last Drag Week, and I would start on a clean-sheet new build that would have more range and run quicker. But I didn't get into the 10s, and I'm not satisfied that I have gotten the car's full potential. I also have to face the reality of a 2 car garage, and the fact that I can probably afford to build more shop space or a new car, but not both right now. Not to mention issues with my new daily and my new-to-me tow vehicle and my dog being sick.

Needless to say, I'm not making a final decision now, or really anytime soon.

But I think I have a general direction.

• I'm going to work on fully sorting out this tune, and getting the full potential out of the Sport inverter. That's going to include not just inverter parameters, but also suspension and tire tuning.
• I'm finally going to get around to thermal management for the battery, so that the car doesn't sit all winter because the batteries don't like even NC's moderate cold
• I'm going to finally get this car out regularly to local tracks and start learning to properly bracket race.
• I will likely try to take the car on Sick Summer (drag-and-drive) next year, and I will keep it ready to go on Drag Week 2026 if need be.
• I will be working on plans for space to store Shocking safely and accessibly so that I can begin work on the next car.
• Once I have the dog issue and the tow vehicle sorted out, I will begin work on sourcing parts for the next car. I'm also planning to play around maybe hacking some NA market EV parts, and maybe building a quick and cheap "fun car" for driving around and testing, rather than for racing.
• The next race car is going to be a huge undertaking, but something I think I'm ready for. For those in the know, I have the SFI 25.3D book sitting on my kitchen table...