Saturday, August 04, 2012

Gettin Rangy

When recently EV-aluating my lengthy list of projects and want-lists, it suddenly became apparent that only one would offer maximal benefit to both the Karmann Eclectric and the iMiEV for minimal cost and risk.  Most EVery EV'er would want to have his range and eat up the track too, but those are usually exclusive attributes.  For me to build a battery or genset-based range extension trailer for the Mitsubishi would involve serious hacking of OEM systems and a near guarantee of a voided warranty.  The genset trailer has already been proven on Karmann Eclectric, but EVen at a steady 3KW into the pack, it only adds a max of 10-12 miles of range to any single trip.  HowEVer, a pusher trailer would give nearly unlimited highway range to the Karmann, and could also operate behind the iMiEV with the factory controls none the wiser!  When being pushed, the i should simply think that it's on a downslope, and allow coasting or regen, whichEVer I command.  In order to make the pusher easily transferrable between vehicles, I plan for wireless accelerator control via an aftermarked cruise control by Rostra that also features vacuum-free electric throttle actuation...
For safety's sake, I'll use one hardwired switch in each vehicle to enable/disable the ignition.
So for those of you who haven't followed this SEVEN YEAR dream, the basic idea is to use an aircooled VW drivetrain to push the EV down the highway, with very simple controls that will leave the tranny in 4th gear and clutch depressed until one is at highway speed, and then energize the ignition and dump the clutch, which will make the pusher roar to life, with remote throttle control.  For safety, one can kill the ignition at any time, adding full engine braking to the vehicle and trailer's service brakes...  Otherwise, when taking an off ramp, one would throttle down the engine, energize a linear actuator that disengages the clutch, and then shut down the engine in a civilized manner...

I'd been hesitant to hack up a Ghia pan to launch this experiment, even though the donor car was terminal, because it would be difficult to do without looking like a hack, and probably have more tongue weight than desired.  Then it struck me that a Type III VW (Notchback) rear subframe was made for the job.  The thing even already includes a tongue that gracefully finishes off the wishbone which holds the engine and tranny.  Now I can add a trailer coupler in place of the original rubber front body mount, possibly even without welding...(or just use a pintle hook).
Has a subframe ever been nominated for a beauty prize?
And of course, my favorite parts scrounger from the Samba, ProjectVW would have one a a great price! 

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