powered trailer idea (EV pusher trailer to make conventional car a hybrid)

[steensn]

Originally Posted by Tango Charlie

Yeah, jack knifing on snow and ice covered roads would definitely be a concern. But thats what sensors and computers are for.
The guy with the EV porsche pushed by the VW Rabbit trailer claimed no oversteer problems even with (if I remember correctly) full push and the tightest turn radius. No snow in CA, though. *sigh*

Get a vehicle with Trailer Sway Control and you won't have a problem! but you also cannot key off your car...

[zjrog]

We were discussing powering the wheels for an offroad trailer. Would take some stress off the tow rig... But we were discussing using the electric motor at slow speeds and the rest of the time let the motor keep its batteries topped up.

[Tango Charlie]

Originally Posted by Andyman

...The trailer could have some kind of power that is more efficient for low power use such as an electric motor, a small gasoline or diesel engine, a hydraulic accumulator, compressed air engine or a flywheel.
This system would save lots of fuel when driving slowly in heavy traffic if the car's engine could be shut off....

I can see that it would have the greatest advantage in town, but why not optimize it for cruising on the highway?
OK. Let me try and put a finer point on the concept I have rolling around in this melon o' mine.
Mr. X gets into his Duramax-powered, gas guzzling PU truck and hitches up his humongous horse trailer. He plans to tow this puppy a couple hundred miles, maybe over a thousand. He enters the anticipated mileage into the (user friendly) 'black box' mounted in his PU truck's cab. This computer interface then calculates the optimum way to run the trailer's auxiliary drive unit. As Mr. X tows his trailer down the highway, the auxilliary drive unit powers the trailer and makes it seem as the trailer is not even there, as far as the load the tow vehicle experiences. Maybe on shorter trips the trailer could even push the tow vehicle a bit.
Try not to think in terms of what you or I are capable of as DIY's. There are engineering firms capable of ironing out the details. I know, 'cause I work for one.
On a CONCEPTUAL level, what are the issues to answer? Here's one;

Originally Posted by steensn

...In the end, aren't you just adding a ton of more weight and in-stability to try and garner minimal payback....

That's the million dollar question. Is it worth it?

[ttoyoda]

The guy with the EV porsche pushed by the VW Rabbit trailer claimed no oversteer problems even with (if I remember correctly) full push and the tightest turn radius. No snow in CA, though. *sigh*

I agree, but has he simulated a panic accident avoidance manuver? Stomp on the brakes while turning the wheel?
Looking over the website I see no mention of it.
I know that when I tow my utility trailer fully loaded, there is a noticable effect on handling when I brake while making even a gentle turn. It is certainly managable in daytime, at lower speeds, with an alert and rested operator who anticipates the effect. Maybe the porsche is so heavy with all the batteries the weight and inertia of the trailer is insignificant.

[Tango Charlie]

Originally Posted by steensn

Get a vehicle with Trailer Sway Control and you won't have a problem! but you also cannot key off your car...

Yeah, no pulse and gliding here.
Trailer Sway Control, you say? Sounds interesting. Thanks for the tip!

[steensn]

Well heck, if you are going to get engineering firms that can work with OE's to interface with all of that stuff ( I know, 'cause I work for one too )

I could see a benefit of powering a trailer to help haul stuff, this coudl lead to being able to downsize truck engines that haul things which could improve efficiency. If you can drop a truck engine form an 8 to small 6 and tow the same thing because you do not need that low end torque, image the fuel economy savings!

[steensn]

Originally Posted by Tango Charlie

Yeah, no pulse and gliding here.
Trailer Sway Control, you say? Sounds interesting. Thanks for the tip!

Yeah, one of the features our company has for trucks. We did the Dodge 1500 for 08 with TSC. Very cool feature, but still won't help someone slamming the brakes and ripping the wheel one way on the highway with a fully loaded trailer. Can only do so much to try and beat physics, but for some odd reason physics always wins!!!

Fun to try though

[Tango Charlie]

Originally Posted by steensn

...this coudl lead to being able to downsize truck engines that haul things which could improve efficiency. If you can drop a truck engine form an 8 to small 6 and tow the same thing because you do not need that low end torque, image the fuel economy savings!

Gee, I hadn't even thought of that angle *slaps forehead*!
Nice, steensn! I'll call it the 'divide and conquer' benefit.
regarding 'trailer sway control':

Originally Posted by steensn

... TSC. Very cool feature, but still won't help someone slamming the brakes and ripping the wheel one way on the highway with a fully loaded trailer. Can only do so much to try and beat physics, but for some odd reason physics always wins!!!

It would have to be a very smart trailer, wouldn't it?

[steensn]

It is all done through a module on the truck, not anything on the trailor. They have semi's that will stop a jacknife now, but they have not rolled that technology into a large pickup tuck yet. Probably will become a "must have" for semi's sometime in the future per government regulation, but not yet.

[aerohead]

I think the idea of a traction power unit in the trailer,providing thrust is kinda scary.I really like the idea for an EV extender as I think ttoyyoda mentioned,and the streamlining concept mentioned by ebacherville.I went to the Solar-500,at Phoenix Int'l Raceway in the early 90s and saw two electric trailers.---------One was Allen Cocconi's,creator of the black-box for the GM Impact,the other was from a Volvo team.Allen drove his electric CRX up from Los Angeles,with a gen -set on the trailer,feeding power forward through an electrical umbilical cord.-------------Neither Allen or Volvo's people seemed to have caught onto the fact that had they streamlined the trailer,they could have probably extended range.I attempted a motorcycle-based,one-wheel trailer for the CRX just to try the streamlining part,but when I tested it,unbeknownst to me,two carburetor vacuum lines were completely burned through.I still got 48-mpg through Texas,New Mexico and Colorado.I'll have to retest to see what it will do with good hoses.