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Westfalia T3 with Chevy Bolt drivetrain

72652 Views 174 Replies 26 Participants Last post by  remy_martian
VW Vanagon T3 with Chevy Bolt drivetrain


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.


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Well, here is exactly the point.
If I connect the 4 wheels brake to the Bolt ABS unit, the Bolt bits will have control of the van's braking.
They will have control with the bad information (front wheel in the rear and vise versa).
Ah... I didn't realize (or had forgotten) that you were planning to go that far. I would be concerned about using an ABS unit with a vehicle that is so different from the vehicle for which it is designed. I'm referring to the fundamental mechanics: the front/rear reversal, plus mass, wheelbase, centre of mass height, mass distribution, brake caliper piston sizes., etc. The basic ABS functionality of releasing the brake for tire which locks up should work (although the hydraulics won't be right), but any brake force distribution or stability control features would be wrong.
Of course a 14.375'' Vanagon cv joint shaft is not ready to fit to the Bolt transmission, so I have to rework the Bolt output shaft to fit the Vanagon cv joint.
... or buy shafts (presumably custom-made) which are splined for the Vanagon outer CVs on one end and the Bolt inner tripod joints on the other end. Is that a possibility?
This is of course the ideal solution.
But I don't know were to ask a quote and I bet the price will be massive.
Likely. A lot of people get a lot of shafts made with splined ends, so someone might do them at a tolerable cost. But there's no way to know without asking.

At the moment, I pay 220$ for two shafts and 10$ for two adapters.
Yes, I have some rework and weld to do, but this seem a cheap alternative to have the perfect cv shafts.
So what's the plan? Cut off the cups of the Bolt's inner stub shafts, turn them flat and true (if they were not cut off on a lathe), machine flanges with holes to match the VW CV joints, and weld the flanges to the stub shafts? I assume that the Bolt stub shaft cup bases are not large enough in diameter to match the VW flanges, leading to the need for an added flange; something needs to precisely centre those flanges (perhaps a dowel on the centreline?). If paying someone else for machining and welding, this isn't going to be cheap, either.
You fully understand the plan.
By chance I have access to a lathe and a TIG, so the extra cost is my time.
Thanks :) The machined locating step looks good.

Once you have worked this out and proven a set, you could have a side business in providing these to other builders. Anyone using a production EV drive unit and adapting to a suspension/axle that uses joints with flanged inner joints could use the same solution.
The solution is in fact simpler.
I order laser cut Weldox steel parts with VW bolt pattern (few $$) and I will weld it to the machined Chevy Bolt transmission output shaft.
I assume that Reid understands that, and is referring to the shallow notch on the far outside edge of the machined Bolt cup which is visible in the rendering.

I assumed that this feature is not intentional, but just the remainder of one of the axial grooves which are normally found in tripod joint cups (and are visible in the photo in posts #105 and #50), but it's a good point - the heads of the bolts (or the nuts on them) which hold the VW joint to the custom flange need to clear the material of the Bolt cup.

It's the same solution I used for my Smart 10 years ago and everything is fine today despite the max torque at CV joint is higher on the Smart (1600 Nm in first gear compare to 1250 Nm with the fix ratio of the Bolt)
I have no doubt that the welded joint can handle the torque. :)

That welding, and especially with a joint which is not simply circular, does raise the issue of balance. Before welding all of the parts will be rotationally symmetric and balanced. If the weld filler material is not perfectly evenly distributed, the balance will be slightly off. I assume that the plan is to get the completed assemblies balanced... or is the imbalance expected to be too small for that to be an issue?
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In fact, the adapter is tapped with M8 holes. So, no nuts or heads bolt on this side.
It's why I use weldox steel instead of 44W. The yield strength is 700 Mpa instead of 300 Mpa, so the tapped holes will be stronger.

About the welding, I hope the imbalance will be too small for that to be an issue.
All worked out, which is what I expected. :)

The rendering didn't show the threads... ;)
"skateboard people"????
I assume that he meant people who believe that any Tesla vehicle actually has something like a skateboard design (a flat structure on which a body is placed). One irritating aspect of this is that there have been "skateboard" vehicles built, at least as concepts and prototypes, but none were ever done by Tesla and none are in production (as far I as I know).
I'm curious about how you jigged it in order to maintain concentricity?
I hope Yabert corrects me if I am mistaken, but my understanding is that because the Bolt joint cup is turned down on a lathe while centred on the shaft, the remaining flange is concentric with the shaft. The adapter is machined to fit to the flange, so the adapter is also concentric. The outboard face of the flange is machined on the lathe so it is perpendicular to the shaft, and the adapter has a step machined in it so the flange face and adapter are parallel. No jig or fixture is required.
Not easy because enter a Chevy Bolt in a Vanagon with a shorter wheelbase isn't easy.
But I think it could be quite ''easy'' to enter a complete drivetrain of a regular EV (Bolt, Kona, Leaf, etc) in a FWD van, a pickup or a SUV with decent wheelbase.
Like essentially all current production EVs, these donors have drive units which place the motor (transversely) on are adjacent to the driven axle, so they can possibly go into other vehicles with the engine adjacent to the driven axle. That makes rear-engine vehicles and front-wheel-drive vehicles potentially reasonable targets, but not most pickup trucks. Anything with a driven beam axle at the rear would require a complete suspension replacement.

I think a compact pickup would be an interesting target for a whole-system swap, but it would really be a complete custom vehicle using an EV powertrain, pickup cab, and some other suspension... all on a custom frame.
Personally, I think it's way easier to design and build a rear pickup truck suspension than a complete 360V battery pack with BMS and heating/cooling ;)
Agreed, but it's not an either/or thing... it's just easier to use a vehicle that is compatible with the drive system.

Also, there is Honda Rigeline with independent rear suspension and maybe some other pickups.
Yes, the Ridgeline has IRS, as do some coupe utilities (but not what North Americans call "pickup trucks")... which is why I said "but not most pickup trucks".

Anyway, the point is IMHO reuse an intact OEM battery pack help a lot to do an easy conversion.
Chop/weld steel sheet (car frame) is simpler than rebuild a reliable battery pack.
Again, a valid point (to some extent, as major structural bodywork is also no joke). And again, a pickup truck would generally need a custom frame, because nearly any modern EV pack (such as the Bolt) is too wide to fit between a pickup truck's frame rails, underneath is too low, and on top would require a really awkward body or box lift... which is why I said that I see a pickup as a "complete custom vehicle using an EV powertrain, pickup cab, and some other suspension... all on a custom frame".
Does the Bolt operate the air conditioner as a heat pump, to provide heat with less power consumption than resistance heating? Adding A/C would be a lot of work and a packaging challenge, but it might have the benefit of better heating, as well as properly supporting fast charging.
This is my goal for a Karman Ghia + Bolt. The underpan battery s very similar to a Bug or Ghia Underpan.
I will use the dimensions of your battery drawing to help me compare dimensioned line drawings of Ghia to the Bolt Battery.
Except that the Beetle platform is a thin panel, and the Bolt battery is a thick box (173 mm or 6.75" tall). Are you planning on having the bottom of the Bolt battery case slide on the ground, or are you planning to jack the Karmann Ghia up like a 4X4 truck to regain clearance?

Yabert's van had a much higher floor than a Karmann Ghia, and now it has reduced ground clearance. That works for the van, but wouldn't for the car, even without the huge hole and structural changes needed to accommodate the taller part of the pack.
Talk here
The bot is quoting random posts and attaching the invitation... I doubt that it can talk. ;) The first one almost looked legitimate because it stumbled onto a post in which Yabert was talking about leaving the forum, but the second makes no sense other than randomness.
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