Westfalia T3 with Chevy Bolt drivetrain

72649 Views 174 Replies 26 Participants Last post by remy_martian, Jan 7, 2022

Yabert

Discussion Starter · Oct 12, 2018 (Edited)

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

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Yabert

Discussion Starter · #81 · Mar 17, 2019

Things are going forwards and I have now a rough 3D model of the Vanagon and the Bolt components (60 kWh battery, motor, power electronic).

I've ordered few laser cut parts to fix the wheel speed sensors (in black on pic) close to the transmission output shafts. I will have the choice to fix 4 sensor on one shaft or the two passager side sensors on one side and the two driver side sensors on the other. No sensor on front wheels.
I will also fix the chevy Bolt wheel bearing seals containing the 96 magnets for the ABS on a shaft collar I will fix on transmission output shaft.
With that, I will be able to use the chevy Bolt powertrain in the room to do some tests.

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brian_

· #82 · Mar 17, 2019

Yabert said:
Things are going forwards and I have now a rough 3D model of the Vanagon and the Bolt components (60 kWh battery, motor, power electronic).

Excellent!

With only electronics behind the drive unit, and the battery roughly centred in the wheelbase, the mass distribution of the electric powertrain will be much further forward than the original powertrain. That's good for avoiding overloading of the rear axle, but not so good for traction or front axle load. Do you have an idea yet of how the distribution will work out?

brian_

· #83 · Mar 17, 2019

Yabert said:
I've ordered few laser cut parts to fix the wheel speed sensors (in black on pic) close to the transmission output shafts. I will have the choice to fix 4 sensor on one shaft or the two passager side sensors on one side and the two driver side sensors on the other. No sensor on front wheels.
I will also fix the chevy Bolt wheel bearing seals containing the 96 magnets for the ABS on a shaft collar I will fix on transmission output shaft.

I assume that the "magnets for the ABS" are for the "wheel speed sensors", and while these sensors are normally at the front hubs (in a Bolt), you are placing them at the inboard end of the shafts, and of course at the rear. Presumably they are needed for the Bolt's ABS / taction control / stability control logic, but ABS won't actually be implemented. Since the logic is still active, if both sets of sensors are installed on the same side, wouldn't there be a possible issue with control if one wheel spins, or even in tight turns, since they are supposed to be providing the two separate wheel speeds?

The logic knows what the average of the two driven wheel speeds should be (because that average is directly proportional to the motor speed), so when one output shaft goes faster than the other the average with the sensors all on the same side will conflict with the motor speed. Maybe the Bot logic ignores that...

It's interesting that the Bolt system will apparently run happily with no speed input from the other two wheels, but needs the driven wheel speeds.

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Yabert

Discussion Starter · #84 · Mar 18, 2019

You are all right Brian.
And it's why I plan to put sensors in pair at each side of the transmission output.
I think that 4 sensors on the same output will work, but will cause problem in an even of wheel spin because at the moment, without sensor, this happen: Turn key on, shifter on drive, shafts spin and spin faster with pressing accelerator, at a moment the system detect the problem and reduce the available power, press the brake pedal and I can restart to spin the shafts.

brian_ said:
It's interesting that the Bolt system will apparently run happily with no speed input from the other two wheels, but needs the driven wheel speeds.

My bet is that is design to run the car on a dyno / test the car without driving around.

Yabert

Discussion Starter · #85 · Mar 20, 2019 (Edited)

brian_ said:
It's interesting that the Bolt system will apparently run happily with no speed input from the other two wheels, but needs the driven wheel speeds.

I did some test yesterday and I have to rectify a fact. With only the two font wheels speed sensors, the car start to reduce power at 40 km/h.
I added the 4 wheel speed sensors on the same output (pic) and I can accelerate without problem.
I also confirm than with the sensors in this configuration, blocking one output shaft (different output rpm between shaft) caused serious problem to the system. The motor try to spin faster.
The mix of ''spin faster'', try to regen without load, try a new acceleration isn't a confortable situation with a motor not solidly fix to a car frame

So, more tests to come with two speed sensors on each output shaft.

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brian_

· #86 · Mar 20, 2019

brian_ said:
It's interesting that the Bolt system will apparently run happily with no speed input from the other two wheels, but needs the driven wheel speeds.

Yabert said:
And it's why I plan to put sensors in pair at each side of the transmission output.

It looks like I misunderstood an important detail, as the plan from the beginning was to put two sensors - which I now understand to be for the Bolt's front and rear wheels - on each side. Still, it ran on just the front wheel sensors...

Yabert said:
My bet is that is design to run the car on a dyno / test the car without driving around.

Yabert said:
With only the two font wheels speed sensors, the car start to reduce power at 40 km/h.
I added the 4 wheel speed sensors on the same output (pic) and I can accelerate without problem.

The dyno test at the end of the production line is one scenario, but I suspect that in general the wrong speed (due to missing the sensors) for the non-driven axle is acceptable at low speeds (but only at low speed) for all of the vehicle dynamics management systems: traction control, ABS, and stability control.

With the sensors for front and rear axles linked together, the car will never appear to spin its tires or lock up the brakes on one axle, keeping much of the dynamic control happy. The relative wheel speeds won't be quite right in a turn (the outside axles will go faster as they should, but the fronts won't go faster than the rears as they should) but with any luck it won't be enough of an error to trigger a response. It should be possible to turn traction control and ABS off, anyway... although that usually requires pushing a switch each time the car is started (since these features default to "on" each time).

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Yabert

Discussion Starter · #87 · Mar 21, 2019

brian_ said:
It should be possible to turn traction control and ABS off, anyway...

I don't have the choice to disable or bypass the ABS/traction control system.
Considering it will not have the proper information from the wheel speed sensors, the system will probably send me in the ditch in an event of wheels spin on ice/snow or in the case of wheel lock after applying brake.

Anyone have idea?
Removing the ABS fuse simply don't allowing the car to shift in drive mode.

Duncan

· #88 · Mar 21, 2019

Hi Yabert

I would not worry too much about traction control or ABS - the basic logic is that it will react if the wheel acceleration/deceleration rate is too high
And the change in wheel acceleration rate when you lose grip is huge!

With the bigger car the vehicle acceleration/deceleration will be lower - so the transition to slip will be even greater

I bet it will work just fine as it is

brian_

· #89 · Mar 22, 2019

Yabert said:
I don't have the choice to disable or bypass the ABS/traction control system.
Considering it will not have the proper information from the wheel speed sensors, the system will probably send me in the ditch in an event of wheels spin on ice/snow or in the case of wheel lock after applying brake.

Anyone have idea?
Removing the ABS fuse simply don't allowing the car to shift in drive mode.

I don't think it will be a problem. The "front" and "rear" speeds should never disagree with conditions enough to cause a problematic response. Specifically for wheelspin, there won't be any front-to-rear difference detected, and if wheelspin is detected (as Duncan suggested) by rate of change, all that will trigger is power reduction or braking of the spinning wheel... but power reduction is what you would want anyway, and the Leaf bits won't have control of the van's braking.

Yabert

Discussion Starter · #90 · Mar 22, 2019

brian_ said:
and the Leaf BOLT bits won't have control of the van's braking.

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).
The other solution is to bypass mechanically the ABS unit by routing the brake hoses out of the unit and simply put plugs on the ABS unit.

Hope that help everyone to understand my questioning.

brian_

· #91 · Mar 22, 2019

Yabert said:
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.

Duncan

· #92 · Mar 22, 2019

Hi Yabert
I would try it

The ABS unit will operate to try and keep each tyre in the "sweet spot" - just slipping a wee bit and it will do this by starting to lock up (deceleration increases massively) and then relaxing a bit

I don't think that it will care about the car at all

Stability control will do the same except compare right to left

The only time it could be bad would be if it got confused or crossed over right to left

tylerwatts

· #93 · Mar 25, 2019

Re: VW Vanagon T3 with Chevy Bolt drivetrain

Yabert

I agree with Duncan but only on 1 condition: he didn't mention that it should be with sensors on the front. Why don't you want to put the sensors on the front (sorry if I haven't seen it).

Otherwise with 2 sensors on each rear wheel (left front & rear, etc) the abs will not activate under braking unless only 1 rear tyre skids and then it will release braking pressure to BOTH wheels on that same side (both left or both right wheels) which isn't good on loose surfaces. And if a rear wheel spins when accelerating the traction control will 'panic' and assume 1 side of the vehicle is skidding so might cause an actual spin by releasing braking and increasing braking accordingly to different wheels to stabilise a stable car.

Either use all the sensors on all the wheels or bypass the abs unit but keep it connected. I'd plumb a small reservoir to lubricate the solenoids too or it could burn out. AND, you must match the driven wheels to the driven sensors, or front sensors on rear wheels and rear on front as the ECU will expect wheel spin from driven wheels and only limit power accordingly.

Hope that makes sense. My vote is keep the abs and use all sensors on opposite front to rear wheels.

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Yabert

Discussion Starter · #94 · Mar 25, 2019

Thanks guys for your inputs. I don't put each sensor on each wheel because the small part with 96 magnets in it is really dificulte to integrate.
Conclusion to come in few weeks.

I've cut the Vanagon floor last weekend and tried to fit the battery cover.
This is promising, but seriously it's not designed to fit there. For those who can plan to convert a Vanagon, maybe consider use a battery from a car with a smaller wheelbase / smaller battery because the fit is really too tight. Or maybe think about rearrange the battery module.
I had to cut some structural beams in the van and I will redesign and weld new beams, but it's a complex job.

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Yabert

Discussion Starter · #95 · Mar 28, 2019

Here is the ring with the 96 magnets for the wheel speed sensors.
I welded it to stainless steel plates and fix it to a shaft collar.
I think I've done an error because the galvanic corrosion between the zinc plated steel and the stainless steel is important.

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swoozle

· #96 · Mar 28, 2019

Yabert said:
Here is the ring with the 96 magnets for the wheel speed sensors.
I welded it to stainless steel plates and fix it to a shaft collar.
I think I've done an error because the galvanic corrosion between the zinc plated steel and the stainless steel is important.

I don't think it's as bad as you fear.
My suggestion (I did corrosion design on commercial aircraft for years):
1. Prime the exposed large stainless surfaces. Those large exposed areas are a major driving force for galvanic corrosion in sacrificial metals like zinc or steel.
2. Get some penetrating corrosion inhibiting compound and spray it in the interface between the two parts. Dinitrol/Ardox AV8, AV15 or AV25, Zip-Chem Corban 23 or Corban 35, etc.

It'll be fine.

CanadaLT28

· #97 · Mar 30, 2019

Yabert said:
Here is the ring with the 96 magnets for the wheel speed sensors.
I welded it to stainless steel plates and fix it to a shaft collar.
I think I've done an error because the galvanic corrosion between the zinc plated steel and the stainless steel is important.

Yabert, you need to hurry up. BusFusion is happening in a couple months and I'm sure you want to show the EV to the other 250 VW busses there, LOL

Yabert

Discussion Starter · #98 · Apr 1, 2019

CanadaLT28 said:
Yabert, you need to hurry up. BusFusion is happening in a couple months and I'm sure you want to show the EV to the other 250 VW busses there, LOL

First time I hear of Busfusion, but it seem interesting. Not too far from here.
Sadly, I will not show this 60 kWh / 200 hp van at the event.
June will be buzzy as I will have my first kid. Hopefully the van will work by may end

CanadaLT28

· #99 · Apr 2, 2019

Yabert said:
First time I hear of Busfusion, but it seem interesting. Not too far from here.
Sadly, I will not show this 60 kWh / 200 hp van at the event.
June will be buzzy as I will have my first kid. Hopefully the van will work by may end

Put it in your calendar for next year. I hope my EV-LT Doka will be ready by then too

Reid_in_QC

· #100 · Apr 13, 2019

I forgot to check in for a while Yan but I'm thrilled to see all the progress. I think that the hole you cut in the vanagon floor looks great - no need to worry! Hope you're having fun and that you're making progress quickly enough for everyone concerned

.

Let me know if there's anything I can do to help. I see you found a willing lathe closer to home (or maybe work) but if there's anything I can do I'm ready to do favours for the born and unborn EV enthusiasts in your family

~ reid

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