In this Video update I discuss:

1. Progress on getting parts
2. Tesla seat teardown
3. LIN bus hacking

1)Parts:

Good progress has been made getting parts.

I scored a beautiful almost new set of original 19″ wheels with Michelin tires from California. I prefer the Michelin tires over the Goodyears since they reportedly have lower rolling resistance. This should leave me with three extra wheels, two of which I can save as spares for backcountry desert roads and one I can sell to someone else who wants a spare.

I have not decided if I’ll integrate the back of the liftgate and taillights into the Stretchla, but if I do I now have a full set of taillights to fit. There was a slightly damaged new part on ebay that was a good deal. It replaces the one broken one I had which was missing the outer cover.

The most exciting time was travelling up to Portland for a Tesla pilgrimage. I grabbed John “Plasma Boy” Wayland as a sidekick since he’s always up for an adventure. We stopped by Precision Auto to check out the damage on Gary’s car (it doesn’t look too bad) and then headed over to the Tesla factory showroom. It was Plasma Boy’s first time at a Tesla showroom and he was duly impressed. I took a few more pictures of the chassis on display. I couldn’t ask for a better reference for my project. Here are the wheels, suspension and the lower part of the frame on display without any body parts in the way, it shows most of the parts I plan to reuse. I noticed something new this time, the radiator louvers were in place and I saw where the orphaned louver motor in my car was supposed to go. This also allowed me to determine the proper actuation angle which will help when spoofing them.

Next we stopped in at the tesla Service center. It was great to meet Jason and Emily who had been so helpful on the phone in the past. Emily and I sat down and went through my parts list to order everything that I still needed. It was helpful to be able to see the parts diagrams and add the nuts, washers and o-rings that I need. I know I’ve whined about Tesla parts cost in the past, and I still think the power steering unit is priced higher than comparable cars and the air strut is more than twice the cost of a MBZ part, but smaller parts were quite reasonable. Seeing that the left AC condenser and fan assembly cost only $299 new, (while people on ebay were trying to get $250 for damaged ones!) I decided to splurge and buy it and the fan controller ($180) as well. I also ordered up the front air strut assembly, knuckle, lower control arms and other small parts that need replacement. It felt easier to spend the money on the parts now. Either I’ve adjusted to the cost of new luxury car parts, gotten over my crazy expenditure on the original wreck, or maybe it just seemed silly to try to search for used parts when my TSLA stock was doing so well. It’s a relief that I no longer need to look for a wrecked car to find these parts used and I’m excited to get the car rolling soon. I forgot to ask when the ordered parts are expected, but I’ll be ready when they come in.

2) Seat Dissection:

I decided that the Tesla passenger seat would not be needed when testing the drivetrain. I’ve been concerned about the height of the seating position in the Vanagon regarding seat rail to suspension clearance so I decided to dissect the Tesla seat while checking out the options for modification. The seat seems pretty heavy at 57+ lbs, much of that is in the steel structure for the seat bottom motion controls. Since the Vanagon has an upright seating position I decided that I don’t need the base angle controls, later I’ll have to decide if I want to make fore/aft adjustment with seat rails. That would be a lot more work and I figure as long as I’m still single (or dating someone with compatible leg length) there’s no real need for adjustment. I can mount it to fit me and worry about other drivers later.

I removed the side bolster “pelvis?” airbag. I have no intention of using air bags in the Stretchla and I’d rather not carry around extra explosives. Maybe when I’ve removed all the air bags I can sell them to help restore some other damaged Model S.

The good news is that the controls I care about like the back angle and lumbar adjustments are easy to retain, and there is plenty of clear space to allow mounting the seat close over the air strut in the best seating position for comfort and visibility.

3) LIN Bus Louver hacking

One goal of this project is to go Supercharged camping soon. That goal is somewhat in conflict with the goal of learning new things. In the past I’ve resisted coming into the modern age of cars especially in such things as LIN and CAN bus communications. This project has given me a great excuse to get familiar with both of these protocols. I’m very fortunate that my friend Debbie Hollenback also enjoys learning new things and she is much better than I at composing C code. Together we’ve had fun working with the radiator louver system.

For those who wonder “why louvers”, it’s simple. Air drag in a vehicle is lower (Some ecomodders report 5% gain in fuel efficiency) when air is prevented from travelling through the radiator(s). Some modern cars like Tesla, with an eye toward efficiency, are implementing automatic louvers that stay closed unless cooling is necessary. The louvers in the Tesla look like they are made by Röchling. They did not reply to my email request for information.

The louver motor controls all seem to have the same three wires. Ground, +14V and data. First I scoped the data signal and found that it looked like diagrams of LIN bus data. Next I hooked up some resistors to protect my trusty Saleae Logic Analyser and downloaded the latest beta code (required for LIN analysis) to my Mac. I love that the Saleae code is multi-platform and works well on the Mac. This confirmed that the protocol is indeed LIN and allowed me to spend some time with paper and a spreadsheet gathering codes and responses from a 30 second snapshot of LIN data from the Tesla. This sort of thing is slow and tedious, the Saleae is not ideal for long data gathering, so the next news came perfectly timed.

Josh at RechargeCar offered up one of his Macchina boards. The Macchina is an Arduino compatible board, very similar to the Mega 2560 with the addition of hardware to run automotive OBD protocols including CAN and K line aka ISO-9141 which seems to be a form of LIN. This is a neat little board that came in very handy, Debbie and I are fans of the Arduino system since it makes simple tasks easy to implement. Although we can code it all the hard way, why bother when the Arduino environment makes simple projects go easily and quickly? You really don’t have to know how to program to get started using Arduino.

Debbie made up some programs (Arduino “sketches”) that manipulated (bit banged) the LIN port initially to send some commands so we could see the louver motor respond. She then modified it to also read back the data from the louver motor. Next she wrote up “sniffer” code to read data on the LIN bus and display it in a easy readable format in our laptops. This made it much easier to see what codes the louver is sending back so we can spoof those.

We’ve (probably) deduced which addresses are used for the missing louvers, and we can only hope that they respond with the same data set as the one motor that we have here. Next up we’ll try to spoof all the louvers and hope that the car likes what we send. We’ll know it worked if the car stops sending louver error codes to Tesla. If that works, we may hook up a set of RC car servos in place of the louvers so we can watch the car cycling them. It’s fortunate for us that the car cycles the lovers on power up. Otherwise it could be a slow process getting the proper codes.

I’m sure that buying a new set of louvers (for $532.40) would have moved things along much faster, but then we would not have learned LIN bus down to the nitty gritty bit level.  It’s a good brain workout to try to decode the nibbles and bits of data and lots of fun for people like us!

Fresh 19″ wheels with Michelin tires

ebay taillight

John “Plasma Boy” Wayland and Gaylen at the Tesla Showroom

Front seat clearance

More suspension pics

Rear structure

Left radiator louver motor

Left radiator louver

Left A’C condenser and fan

Fan controller

Fan controller

Small parts

Stock is doing well

Seat rails use up a lot of height

Heavy and tall seat mechanism

Side bolster “pelvic?” air bag

LIN bus analysis

Decoding LIN commands

Salaea interface, great for figuring bit timing

Debbie Hollenback

Macchina board

Saleae Logic tool

What will it cost to do this anyway?

Do I hunt for a better deal, or make progress faster? That is often the question with a project like this one.

You may think that money is not an issue for someone who can afford to buy a Tesla, but we all have our limits and this project has been one to push my comfort zone. I suppose that that’s part of what makes it all interesting as well. I find it rather amusing to watch my initial resistance and then my justifications for spending funds along the way. Much of my life I’ve been concerned with money and here I’m strangely driven toward a large optional expenditure. It’s not like I’m concerned about making rent or food budget here, I’m very fortunate in that way these days, but this does involve what I would call considerable sums from what most people would suggest I’d do better to save for retirement.

It all started with getting the Tesla base vehicle. Six months ago when I started this project my budget seemed simple. I’ll buy a totaled Model S for $18K or so (seems about right for a luxury wreck), throw in a few grand to get the essentials running and then it will take much labor but very little cash to merge it with the stretched Vanagon body. Not pocket change, but not bad at all for such a cool EV. Ah grasshopper, you have so much to learn. After losing a couple auctions with my low bidding limit I reconsidered my budget. Had I not justified $30K for a battery pack on the conversion project this replaced? And is not $10K a perfectly reasonable amount for a powerful drivetrain? What about the value of a huge panoramic sunroof? That practically essential tech package? Don’t I need a test bed for high power AC drives in order to further my business? That retirement fund isn’t earning much anyway and besides this is going to be fun! I’ll sell a few vehicles to help with the cash flow and free up some work space as well. Within a few weeks I had talked myself into a $40K bid limit. Not that I’d need that much, no, I’m sure I’ll get one for $30K. Did I mention how I used to teach “Creative Justification 101”? I waited and watched some more. A number of less than ideal auctions went by with issues, no air suspension, the smaller 60 kWh battery, $50K selling prices, those were not for me. After over three months of auction watching my car showed up. The damage was not too bad, it had almost every feature I wanted, lacking only the dual onboard chargers, and best of all the passenger air bags were all intact so the interior was perfect. Very nice! Not only that, the pre bid value closed at only $12,300. It’s not uncommon for the final bid amount to be twice the pre bid, but not often much more than that. I thought long and hard about my bid limits for this car the night before the auction deciding I would go as high as $38,200 but not to my $40K hard limit. If I didn’t get it for that then I’d accept it was “not meant to be”, thereby giving my guardian angels a vote.  Either I have a lesson to learn about expecting a good deal, or my guardian angels have a great sense of humor because the other bidders stopped at $38K and I won it for $38,100. As I watched it bid to $38K I knew I had to mentally let go, and even when I “won” it, I had to wait for the insurance to approve the sale since they had a $40K reserve, but I held tight and still won it. In the end auction fees, broker fees and shipping brought it to $42K.

$42K for a totaled car. What-Had-I-Done!? Prior to this, my most expensive car was a new Prius for about half that, and this one was a severe wreck. I just had to laugh. It started as a nervous laugh but now that the car has been here almost a month I can really laugh about how nutty it seems. Oh well, I reserve the right to do nutty things when I can, I guess it reminds me I’m alive. I’m grateful to have this freedom. The Stretch project in 1998 felt similar. Back then the front half was also the most expensive car I had bought by a factor of two and I promptly cut it up. It feels a bit like I’m trying to cut up my mental blocks. But this is not the end of those.

I think I got over the cost of the donor car. I’m still working on adjusting to the cost of luxury car parts. The steering rack mounting ears were broken in the accident. This is not uncommon in a wreck so you just replace the rack. I’m well accustomed to old Volkswagen prices and I normally pause a bit before I spend a few hundred dollars on a steering rack, but $3066.60 for one? This pause it taking longer.

Now I have a choice, do I buy a new rack or try for some alternative fix? Buying new is quick but costly. Alternatives take more time, carry more risk of lost time and money but can have hidden benefits. As a child I wanted a new go-cart, it was there in the Sears catalog and it would have been so cool! But buying a new go-cart was not an option in my family and so I had plenty of time to ponder alternatives. Eventually I built a much more creative go cart for almost no money and learned how to build things along the way. I’m not vouching for its safety, but I survived and gained valuable skills. I would have preferred the easy path of a new go-cart at the time, but the financial limitations forced me toward an education that my friends from wealthy families missed.

Back to the steering rack. If the Tesla were a few years older I might buy one from a wrecking yard for under $1000, but as of today I have not found a single Model S being sold for parts. A friend suggested having it welded so I took it apart. Now this part was fun, I’d never taken apart a modern EPS rack. If you are as curious as I am about these you can read about them here: It’s the high end Paraxial Servo Unit on page 8 and 9. I didn’t find this document until I had it apart, so I had the joy of discovering the fine brushless motor and belt, the integrated torque sensor and even how to put a few errant balls back in the recirculating ball gear before reading about them. With it apart I was able to take the housing to the finest aluminum welder in the region. He said there was a good chance he could weld it up, but complications such as the proximity of precision surfaces and my desire to run it on a heavy vehicle had me agreeing with him to look into other fixes first and only consider welding as last resort. The rack is made by ZF Lenksystems and with help from friends and Google we’ve found the cast housing may be the same as the one on a 2012 right hand drive Land Rover Evoque. There seem to be more of those in the scrap yards than there are Teslas. There’s one on eBay in the UK for $327, I’m awaiting more details from the seller to see if the housing is the same so I could swap it. Maybe this will work, but I’m warming up my justifications in case it doesn’t.

The steering rack is just the most expensive part. My list of parts to get it rolling comes to $8000.61 and I’m sure I’m missing some things. Many of the smaller parts are clearly worth buying but the air strut at about $1800 has me looking for alternatives as well. Eventually I’ll either find a workaround or get tired of looking for alternatives and just spend the money. I don’t want to wait too long to order parts since I hear Tesla parts sometimes have long lead times.

I wanted to write this post to let you know that I’m still working on it, even if it feels like nothing is happening on the outside. It may take some time to adjust my comfort zone, but with some minor delays the Stretchla will make progress.

Photo © Otmar Ebenhoech

Photo © Otmar Ebenhoech

Photo © Otmar Ebenhoech

Photo © Otmar Ebenhoech

Photo © Otmar Ebenhoech

Photo © Otmar Ebenhoech

Photo © Otmar Ebenhoech

Photo © Otmar Ebenhoech

Photo © Otmar Ebenhoech

The eagerly awaited day has come

Yesterday at 8 AM I got a call from the carrier, my Tesla was on the way and should show up by 11. I must admit to being nervous. Everyone I spoke with about auto transport had stories of trouble; missed dates are common as are damaged vehicles which they claim were damaged when picked up. The shipper assigned to me had a BBB “F” rating and I noticed them being dishonest with me the first time I called them. Let me be very clear so no one gets the wrong idea, Tesla had nothing to do with this, it was organized by a broker that works with the insurance auctions. Thanks to warnings from others I paid my deposit at the time of order placement but withheld the bulk of the payment as COD. This seems to motivate them to actually deliver the car. In the end my Tesla showed up only a week late and aside from the missing key and lots of dirt from a cross country trip in the winter it seemed no worse for wear since it left the auction in New York. The battery pack, that most critical part, had a few new scratches but they were very minor and no worse than the ones caused during the initial accident. It seems they had been sliding the car on and off carriers with the parking brake on, clearly they had not studied how to turn the brake off (admittedly a challenging feat) . A call to the auction yard verified they had record of the key being picked up by the shipper with the car, contrary to the claims of the shipper and in the end we agreed that I would withhold the cost of a replacement key from the COD amount until they could produce the key. I suspect that I’ll never hear from them again. Most fortunately I had a second key that I had bought from the previous owner and so I was able to jump the 12V and unlock the parking brake to help it off the last truck. Many thanks to Arthur for arriving just in time to help me push the Tesla around and get it on the lift.

Damage Assessment

I’ve spent much of the last two days assessing damage from the accident. I’ve worked with a number of wrecked cars over the years, but this is my first aluminum one and I am very impressed with how it responded to the impact. I’ve worked with steel cars and aluminum parts before, but somehow it never really sunk in how well aluminum absorbs energy until I reviewed this wreck in detail. Of course aluminum by itself would do little without the impressive engineering that clearly went into the Model S design. The down side of the aluminum is that more of the front suspension is damaged than I had hoped and the old steel tricks of pulling it back in place and welding it up will not be appropriate. That’s a small price to pay for the well-being of the occupant. The subframe and upper frame have both been damaged. The electric power steering rack is broken off its mounts. I have a copy of the original parts cost estimate for the repair. Including body panels (which I won’t be needing) and not including a battery the total is about $29K. This does not include some other parts I’ve found damaged. Parts like the $3000 steering rack do give me pause. I’ll either need to find a creative way to fix it, find someone parting out a Tesla (I haven’t found anyone yet) or save up for new parts. It seems I get to work on my issues with “luxury car sticker shock”. 🙂

Next Step

My next step is to get the system happy enough that I can activate the HV (high voltage) system, check and charge the main battery and see that the drive motor engages. Pulling panels and inspecting parts is providing a fun education, I’m on the steep part of the learning curve for now. I’ve found that someone completely removed the “First responder loop” that normally would just be cut. This wire has one wire loop to disconnect the SRS and another that shuts off the HV battery system. It’s not surprising the car won’t drive or charge without it. The first responder loop consists of 2 wires with each shorting 2 pins on a 4 pin connector. With my service center being a 3 hour round trip away I was trying to figure out the wiring so I could jump it until I get a new cable.  With no service manual or wiring diagram available to the public (at least that’s seems to be the case for now) it’s certainly a challenge.  I’ve traced one of the 4 terminals, but am still pulling panels to try to trace the others so I can be sure of the functions. In the meantime, while I’m trying to find replacement parts for something less than full retail price I’ll work on fixing subsystems and hopefully whittle away at the 10 to 12 error messages usually on the screen. There’s everything from “windshield washer low” to “Needs service contact Tesla”. Mostly they have to do with much fluid being lost in the wreck . Speaking of errors, that never ending triple beep that plays anytime I’m in the car is getting a bit old. In the old days you’d just reach up under the dash and pull what was vibrating, but we live in a new world. I’ve also found that it’s hard to do anything inside without turning the car on. Once I tried to manually open the door with the key far way and the darn alarm went off, dual horns bouncing off the shop walls. I’m no fan of alarms and hope I can disable this one someday. I can power the car down on the center screen and as soon as I get out it turns back on. It seems the only way to get quiet time while I’m inside is to disconnect the 12v battery. No doubt about it, this car is very modern! Reviewing the forums I find there are many operational tricks I have yet to learn, maybe making it stay shut down and quiet is one of those.

Planning

Remember that musing I had about dropping down to 18″ wheels in my last post? As with so many things early in the planning process, it was pure fantasy. One look at the steering knuckle, still connected to the loose wheel, shows that there is no way a smaller wheel is going to clear on the front, no matter what the brake caliper clearance is. I’ve put up a WTB post for a used wheel and tire (or two) on the TeslaMotorsClub Forum.  On the plus side, the sunroof works very well and looks like it certainly could fit the Vanagon roof, helping with an aerodynamic transition to the pop top height. It’s a beauty! Here is a short time lapse of the arrival and a few pictures of the car and the damage.

On a crutch. Photo © Arthur Hebert

Photo © Arthur Hebert

Photo © Arthur Hebert

Photo © Arthur Hebert

Photo © Arthur Hebert

Photo © Kirk Swaney

Photo © Kirk Swaney

Photo © Otmar Ebenhoech

Otmar testing the small seats. Photo © Hai-Yue Han

Broken steering rack mount, Photo © Otmar Ebenhoech

Radiators are always the first to go in a wreck. Photo © Otmar Ebenhoech

Photo © Otmar Ebenhoech