ICE on a trailer?

7843 Views 78 Replies 8 Participants Last post by brian_, May 25, 2019

Ken R

Discussion Starter · Sep 26, 2018

Hi,

I live in a small city in a low-population area in the central USA.

I've been interested in electric vehicles since before auto makers started releasing them a few years back. (Don't talk about the early days of autos, I'm talking like Chevy Volt)

My problem with typical EV projects is that they focus on some econobox car, which is impractical for me. I'm 6'4" (193 cm) and those cars just don't hold somebody my size. Not only that, I'm a foster parent and we have some variable number of kids, and then the people in my real family, and then a couple dogs, and whatever fishing/camping gear I want to take with me.

My current vehicle is a 15 passenger van. It's a 2010 Chevy Econoline 3500, extended. There are 4 bench seats and 2 buckets up front. 3 of the bench seats hold 3 people, the last one holds 4. Usually the back seat is out to make room for dogs, but I have literally had every other seat used. The van has a V8 in it, and it's adequate for acceleration but nothing to write home about. The most economic speed is 55-60 mph. My area generally has 2-lane blacktop roads at about 65 mph, and interstate speeds of 80 mph. The existing ICE gets terrible fuel economy in town, usually less than 10 mpg. On the highway it can get close to 20 mph depending on the wind and such.

My normal day involves driving around town a few miles, easy for an EV project. Most days the van just doesn't move at all. But when we take a trip, we use the van. When we take a trip, we WILL go more than 300 miles round trip.

So here's my question finally:
Consider a van conversion, set up for in-town driving. I can't sacrifice a whole lot of weight to batteries as I use the van to carry a lot of people. But they're little people usually, maybe as many as 5 adults but the rest are miniatures. I figure this is a do-able EV conversion and probably straightforward.

The van has an OEM trailer hitch, something like 7500 lbs weight rating.

What I'm thinking of is a trailer for trips. Probably double-axle. It would have:
1. An internal combustion engine, possibly the same one that's in the van now.
2. A big fuel tank.
3. A storage area for luggage.
4. More batteries.
5. Possibly motors to assist with driving force.

My idea is that, in town, the van is a pure EV. When I go on a trip, I hook up the trailer which converts it into a hybrid. I would obviously need a big high-voltage umbilical going up to the van, and a pretty good control unit.

Is this a feasible idea, or are there too many safety or legality concerns? AFAIK there are no laws forbidding a running engine on a trailer, but I haven't really researched it.

Thanks for your time.

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brian_

· #50 · Sep 30, 2018

Ken R said:
I was thinking that I could replace the rear suspension with independent suspension, run a shaft to the centerline to a gear box mounted on the frame of the van, and then power each wheel from a motor with a fixed gear ratio. Motors sticking out in front or behind the drive shaft.

This would look roughly like the setup from Quantum in a Fisker Karma... and given the huge size of the Karma's motors, an actual salvaged Karma complete motor and transaxle unit might be suitable. Sorry, the Karma's motors are PM, not induction.

Previous discussion: Fisker Karma motor ?
(photo of Karma's Q-Drive attached)

Ken R said:
I was thinking 3-phase induction motors with a separate controller for each wheel, and some sort of sensor and controller to provide traction control to avoid spinning one wheel on slick roads.

Although I assumed that the Karma uses each motor to drive a wheel (separately), it's also possible that both motors drive one differential; I've never seen a good internal description.

Ken R said:
By my guess the van wheel will be turning about 780 rpm at 65 mph, so probably 4.6:1 or so ratio if I'm using 3600 rpm motors.

That's really slow for electric motors of this size. You can use smaller motors for the same power with no loss of efficiency if you turn them faster, and have suitable voltage available. The Karma appears to the motors up to at least 6,000 rpm, and other hybrids and EVs (e.g. Tesla) run up to 12,000 rpm.

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brian_

· #51 · Sep 30, 2018

Ken R said:
I've looked into the mechanics of 4-link custom suspension, and I was thinking of either building or buying something for the rear (prefer buying!). Maybe I should consider the front as well? 4-link is incredibly better than stock suspension when it's done right..

For the rear, coil (or air) springs and control links certainly provide better handling and ride than leaf springs. Ram pickups have all gone to coils and control arms at the rear. There are aftermarket kits, from low-riding setups for custom trucks, to jacked-up systems for off-road (or looking like you go off-road

), to heavy-duty solutions with air springs for trucks which tow and haul. Kelderman makes a bunch of bolt-on systems, but I don't see any for vans.

The rear of the GM full-size SUVs have coil springs and control arms, using GM live beam axles like a Chevy van. The frame details are different so it wouldn't just bolt in, but an adaptation would probably be possible

Beam axles with control links and coil springs are common for the front suspension of heavier light trucks, such as Ford SuperDuty, and Ram 2500 and up. That's definitely an upgrade over the leaf springs used on medium-duty trucks, but the front can easily be independent...

Ken R said:
Maybe it would be an advantage to try to find some front suspension parts that would work with 4wd?
...
Maybe a suburban's front suspension might be adequate?

The Chevrolet Suburban and Tahoe, GMC Yukon, and Cadillac Escalade are all built on the same forward chassis as the Silverado and Sierra pickups. These vehicles all have independent front suspension, both 2WD and 4WD, and all the way up to the "one ton" 3500. This seems like a reasonable donor of parts for a van, but there are also factory AWD models of the Chevrolet Express van - so there's a driven axle front suspension available.

Ken R said:
My current vehicle is a 15 passenger van. It's a 2010 Chevy Econoline 3500...

I assume this meant Chevy Express 3500 (Econoline is a Ford van model).

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brian_

· #54 · Oct 1, 2018

Ken R said:
Where I live is not exactly an EV-friendly mindset. For some reason unknown to me, the desire for an EV is an indicator of your political leanings, and this is a very conservative state, and not in a particularly educated sort of way IMO.

What I'm getting at is that if I'm going to find a broken EV I'm going to have to go somewhere else to get it. Not sure I'm comfortable buying something sight unseen.

Whatever the sociopolitical basis, the popularity of EVs certainly does vary by area. Here in Alberta you can drive for days and not see a single EV, so the salvage supply is essentially nonexistent. Whatever some people say about salvaged components being readily available, for many people they are not locally available.

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brian_

· #55 · Oct 1, 2018

Ken R said:
I'm not entirely sure there's a 4wd pickup equivalent to this van. It might be not too far from a 1-ton I guess.

The Express has been available in 1500 ("half ton"), 2500 ("3/4 ton"), and 3500 ("1 ton"), corresponding roughly to the load capacity of pickups of the same designations. I assume that they're very similar mechanically, but there will be component differences. Which one do you have?

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brian_

· #56 · Oct 1, 2018

Ken R said:
I hadn't really found any EV-specific motors that size yet. The examples I found of ACIM motors in the higher power ranges looked to be about 11-13k rpm.

That maximum speed range is typical for current EVs, which typically run 360 V (nominal) batteries. Motors built for EVs with much lower max speed are typically intended to be an easy swap into a truck for conversions, or to work with lower voltages.

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brian_

· #57 · Oct 1, 2018

Ken R said:
I didn't know about the 4wd express van. I believe I have coil springs in front, I know I have leaf springs in back.

Coils in front... but in an independent suspension, right? The pickup truck and van suspensions are similar, but at GM the pickups usually use torsion bars because the coils are in the way of the axle shafts in the 4WD. I haven't found an illustration of the Express AWD front suspension yet.

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brian_

· #58 · Oct 1, 2018

Ken R said:
The thing is, 4wd tends to use a pumkin differential. If I'm using electric I don't see how that's beneficial. It seems to me that a frame-mounted motor and single-speed gear set (gears on centerline) with one motor and gearset for each wheel, and then a shaft with CV joint going out to an independent suspension would be the most mechanically efficient. Maybe an aftermarket 4-link?

I assume what you mean by a "pumpkin differential" is a live beam axle, in which the differential is in the axle housing (in a bulge sometimes called a pumpkin). Yes, that's the tendency for 4WD trucks, but not for the "half-ton" size at Ford (the F-150) or any of the pickup trucks at GM... those use an independent front suspension.

If you do use a live beam axle in the front (which is a common approach for aftermarket 4WD conversions of full-size vans) then a 4-link would work better than leaf springs, and the motor can sit under the cab area floor (to one side of the original transmission location, because the front differential is offset to one side to clear the engine and match up with the shaft coming from the transfer case).

With a driven independent front suspension (from an Express AWD or 4WD GM pickup), if the original differential is used the motor could be mounted directly to the diff input (if diff's ring and pinion gears give enough reduction for the motor chosen), or back further.

Ken R said:
Following that logic, if I were going one motor per wheel and used 4wd then I would expect standard EV motors to work fine.

I agree that four motors of the size commonly found in compact EVs would suit the van.

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brian_

· #59 · Oct 1, 2018

Ken R said:
I haven't seen any suspension kits for vans either, because I assumed it was similar to a truck suspension.

It is, but for a bolt-in kit to work the frame and axle need to be exactly the same (at least in the areas where the kit attaches), not just similar in design.

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brian_

· #62 · Oct 1, 2018

Ken R said:
3500 extended.

Ken R said:
As mentioned in my previous post, my van is rated at more than a ton cargo capacity. I believe it's around 3000 lbs. If you count 15 adults with realistic weights you definitely have more than a ton. I don't know if it's the same running gear under there as a regular 1-ton vehicle or if it's heavier.

3,000 pound payload is not much for a 3500-series pickup - that's more like 2500-series, and even an ideally configured 1500 can get close to that. Recent 3500 Express vans have about 3800 pound payload, so we could assume that; the corresponding GVWR is 9600 pounds (three tons of van plus two tons of payload equals five tons of loaded van... about the same numbers as a 3500 pickup. "One ton" (3500-series, or anything GM labels as "HD") pickup components would be fine... if they fit.

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brian_

· #63 · Oct 1, 2018

Ken R said:
I'm pretty sure the existing engine, rated at 350 hp, can't pull that power continuously. The electric motors I would use would only need to match the abilities of the existing engine, or preferably surpass those abilities by a noticeable amount.

Engine ratings are essentially continuous, although few people run them that hard, and lifespan would be short (meaning less than the usual 200,000 miles or 300,000 km expected of a modern light duty vehicle, not blowing up in a few minutes!) if worked that way. A high-voltage modern electric motor can run at the rated power over a broad speed range, while the engine only hits that peak at the top of the operating speed range, so the motor rating can be lower than the rating of the engine being replaced, for the same performance.

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brian_

· #64 · Oct 1, 2018 (Edited)

For the front, it looks like 4WD with the 3500 van's independent front suspension can be done... Quigley does it. You wouldn't want to pay what Quigley would charge (even if they would do your older van), but they seem to have worked out that the parts will fit and how to do it, with a custom front crossmember (because the van and pickup frames are not the same):
DIY: 2500/3500 Van IFS 4WD Conversion

Quigley Products > Quigley 4x4 GM Vans > 4x4 Models
"K-Series" means 4WD GM pickup trucks

If you use a salvaged EV drive unit or some other motor-and-gearbox arrangement, instead of the factory final drive unit, you would want a crossmember to fit that instead... so it would be custom and unique to your van, not just a copy of Quigley's component.

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brian_

· #67 · Oct 3, 2018

Ken R said:
It seems to me that if someone were to want one of their conversions the best way to do it is to just deliver them a brand new van. The conversion seems likely to cost several times the new price of the vehicle no matter what, so the van itself would be sort of an afterthought. If you're going to have a company do the conversion I would think you'd want it to last as long as possible, hence a new van. Or maybe a 1-year-old with 2k miles on it.

I agree.

Ken R said:
It would be neat to be able to dig around in a van they converted to see how they did things. They surely know more about it than I do, and while I might want to do some things differently I'm sure I'd learn a lot from what they do.

That's why the discussion in the DieselPlace forum would be valuable, because it works through the details of the conversion... or at least it appears to - I didn't register for their forum so I haven't seen the images.

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brian_

· #79 · May 25, 2019

joekitch said:
... actually, you know what, i'll make a separate thread on this question

Great, but can you delete your post, or at least the image attached to it, because it forces the page to display very wide (to match the width of the huge image), wrecking the formatting in a web browser so that the the page must be scrolled side-to-side to read text.

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ICE on a trailer?

Ken R

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