[Yabert]

VW Vanagon T3 with Chevy Bolt drivetrain

Hi

I'm asking myself if DiyEcar is still the best place to put a build thread and to obtain help.
It was the case many years ago when the overvolted forklift motor was the rule, but now?

Well, my plan is to put a 200 hp 60 kWh Bolt drivetrain in a Westfalia... Exciting right?
Yes, but all the electronic and control in the Bolt fear me a bit.
Anyway, I will have the crached Bolt in few days and the West in few weeks.

Let me know if you have advice or help.
Thanks

 

[Yabert]

My only question at the moment is to know if there is a better place than DiyEcar to start a build thread or if this one is still relevant.

About the Bolt motor, my understanding at the moment is that the reduction gear housing don't sticks up, but the protrusion is facing the front of the car.

https://www.motortrend.ca/en/news/2017-chevrolet-bolt-ev-drivetrain-first-look-review/

 

[Yabert]

Few pics from the Bolt.
By a lot of chance, no major component was destructed by the accident. Even the fluid heater in the passenger corner wasn't touch despite there is a lot of sheared steel sheet in this area.
Globally, the windshield, the dash and the passager pillar are destruct, but all the others parts are fine.

But, despite I replaced the lost MSD with a temporary solution and I cleared many DTC, the car still don't move at the moment.
By chance, I'm able to see that the battery cells are in good shape at 3.8V.

Next step is trying to find why this car don't move.

 

[Yabert]

Types of projects where the Bolt still thinks it’s a Bolt but with a Westfalia body.

Kind of. I plan to do a Westfalia who think it is a Bolt
Plan to transfers all components needed to allow this computer on 4 wheels (the Bolt) to work properly inside a West body.

You'll have to re-flash the controller to erase the permanent codes set by the airbag control module.

I have the VCX nano and I erase many DTC and reset few event, but it seem impossible to reset properly some event.
I'm not able to reset the crach event and I'm not able to communicate with the airbag module to apply the procedure to clear secured high voltage DTCS.
I bet I probably need a new airbag module to allow the car to move despite no airbag and no belt pretensioner have been activate.
Complex new car...

 

[Yabert]

I assume that the plan is to use just the drive unit (motor and transaxle) - at the rear of course - in a custom subframe with the original VW suspension... so none of the Bolt suspension parts will be used. Perhaps they can be sold to recover some of the cost of the project, if they are not damaged. On the other hand, there may be no market for them yet (since the car is so new).

Right, right and probably right.

 

[Yabert]

I have the VCX nano and I erase many DTC and reset few event, but it seem impossible to reset properly some event.
I'm not able to reset the crach event and I'm not able to communicate with the airbag module to apply the procedure to clear secured high voltage DTCS.
I bet I probably need a new airbag module to allow the car to move despite no airbag and no belt pretensioner have been activate.
Complex new car...

Is anybody know if I absolutely need to change my airbag module to communicate with him.
Seem like I absolutely need to communicate with him to be able to drive the car and it's seem than when something detect a crash event it destroy this module. Or at least make communication impossible.
A new module is expensive and I would like to have inputs before paying.
Thanks

 

[Yabert]

Weather is particularly cold this year here in november and I have to move fast to put all the powertrain/battery parts inside (move by hands).
The snow is approx one month in advance so dismantle the Bolt is a pain...

Anyway, I finally been able to drive the car after I cleared some high voltage DTC (No new airbag module needed). I also tested the charge.
So, I remove radiator, charger, junction box, DC-DC, drive and motor from the Bolt.

Next step, the 950 lbs battery

 

[Yabert]

were you able to pull CAN-logs? for example to re-use a complete battery?

No. Sadly, control and programmation stuff isn't my strength.
My plan is really to integrate everything the complete Bolt powertrain need to be happy in his new Vanagon body.
At the moment, I identified:

Needed - the front wheel sensors, the abs module, motor module, battery module (2x), chassis control module, air bag module.
Not needed - the power steering, the airbags, crash sensors, windshield mirror, doors sensors and many lights and presence sensors.

Some others tests will let me know if I can remove or bypass more stuff.

 

[Yabert]

I can see that the Bolt's power steering might not be needed to keep the Bolt drivetrain bits working, but what's the plan for steering boost?

manual steering rack to keep arm in good shape and strength http://www.busdepot.com/251419061
1979 Westy after all...
At the moment I'm not 100% sure to don't reuse the Bolt power steering, but it's the plan at the moment.

 

[Yabert]

More news.
I removed the battery from the Bolt. It's really easy with some good tools despite I'm working in the snow.
Yes, I forgor to remove the MSD first...
I had to dismantle the entire battery to be able to move by hand all the part inside (no garage sadly).
In less than 4 hours all the modules and the battery box was inside. Thanks to the video 2017 Chevrolet Bolt EV Battery Disassembly from Weber auto https://www.youtube.com/watch?v=ssU2mjiNi_Q
Each of the 5 modules weight around 150 lbs and the battery box around 200 lbs. Not too bad when you move it with 4 hands.
At the moment I have to say that this Chevy Bolt is well build and easy to work with.

 

[Yabert]

Finally, I rebuild the Bolt battery inside.
With all the modules and cooling plate in hand it seem I could probably rework the fifth module and move it by 90° in the middle of the pack (pic-1-2).
This rework can allow me to don't cut some part of the Westfalia Frame.
Anyway, I have to choose between cut the Westfalia frame and don't touch the battery or cut the battery cover and build new support for the fifth module. Of course this second option imply re-routing of the coolant circuit and some wires and busbars.

I still have to remove some wire harness and module inside the Bolt and I will have everything I need to run the motor inside.

 

[Yabert]

Is there some mechanical engineers who can help me / confirm me that a shrink fit coupling assembly will work for my situation.
The situation is I have to fix a 26mm Chevy Bolt cardan shaft to the 28mm Westy cardan shaft. Both shaft are steel (unknow type)
I plan to rework an A513 1-1/2'' x 1/4'' wall DOM tube to link both cardan shaft together by press fit and add a Tig weld at each end after (hope picture help to understand).

Based on tribology online calculator, in my situation, the interference fit itself can pass over 3000 Nm of torque. The Bolt have a torque of 266 lbs-ft at motor shaft and a gear ratio of 7:1 for 1862 lbs-ft at cardan shaft or 2527 Nm.
http://www.tribology-abc.com/calculators/e6_2.htm

So, advices?

 

[Yabert]

Hi Yabert
Looks good to me

Ok, thanks.
But do you have some formulas or calculations (more than an online calculator) to be sure out of doubt that this interference fit will be perfect for my situation?
It's not on a 10 000 km road trip with the familly that it's time to constat that my calcul wasn't right

I can imagine myself stopping at the GM dealer to ask Chevy Bolt parts for my Vanagon , but not for modified parts.

 

[Yabert]

That is essentially what I am doing.

If I understand correctly, you are talking about a loose fit (0.001'') and all the torque will be transmit by the weld.

In my case, the press fit (0.001'') itself should transmit over 2000 lbs-ft of torque.
The weld is there for redundancy... or to induce undesirable stress concentration (not sure about this one)

 

[Yabert]

On your collar: if you drill at least two holes through coupling and weld down to the inner tube the joint becomes as strong as the inner tube. Required procedure on aircraft tube structures

Do you have some visual support or link to show me exactly what you are talking about.
A quick internet search don't allow me to fully understand.
thanks

 

[Yabert]

Ok, it's what I had in mind. They seem to call this Rosette Welding.
But it appear that I have bad experimentation with this type of weld when they are used for torque transmission in a shaft.
On the aircraft structure this kind of weld is used in tension / compression in addition to others welds between tubes. It's not the same case on a driveshaft.

As you can see below, the first shaft on my Smart was rework using rosette type welding and it fail after few thousand kilometers.
After I reworked the shaft with a complete weld around the tubes and it's what move my Smart today after many thousand of kilometers (3e pic).

Each assembly was press fit tubes and only the weld type was different. Of course, the coupling inside or outside the tubes have played an important role too in this case.

Couple of other points
Pressing the two together is not as "safe" a process as doing a heat shrink - I would be looking at pressing them together with the outer tube as hot as you can get it

Thanks for the tip. I understand the fact and I plan to heat the coupling to obtain a slide fit when heated and an interference fit when shaft and the coupling are at the same temperature.

 

[Yabert]

Haha! Nice coincidence.
I'm exactly at this step to fix the charger/inverter/junction box/dc-dc over the motor and reconnect the cables.
Thanks

 

[Yabert]

It's a bit the mess in the room at the moment. It's mainly caused by the huge wiring harness.
I have to find a large and tall support to fix it to the wall.
I have to use it almost completely to maintain all the desired fonction of the Bolt in the West.

 

[Yabert]

Small update
The stack comprised of the motor, controller, charger, dc-dc is now in place.
I have to reconnect few wires minus the seats and the airbags and find a stable place for the airbag module.
This one could take action if it think that the car crach (module drop to the ground) or if it think that the car is in an important angle.

Also, I have dismantle the cardan shafts.
After have cut it, I will to be able to do the press fit with the other half Vanagon cardan shaft.

 

[Yabert]

I was wondering if the modules consisted of inter-leaved aluminium plates between each cell or group of cells. I find battery thermal management quite the challenge...

My understanding is that each 3 cells group is stack between two aluminum plates. Those ones are in contact with the cooling plate in the bottom.
So over 6 cells face, there is only two cells faces in contact with aluminum.
IMHO the Bolt battery cooling method is not ''high performance''. It's there to slowly regulate the temperature, but not to allow high discharge or charge rate.

Not the same thing with the chevy Volt cells. As you probably know each cell have at least one face in contact with a cooling plate.