RE: my very heavy and lossy EV LandCruiser idea... :-)

["Roger Stockton" <stockton@racalcanada.com>]

Hi Will,

'79 SWB, huh?  I seemed to recall you mentioning a vehicle weight of ~4500lbs,
so the values I quoted were for the "wagon" version.  Here's the data for '79:

Land Cruiser (SWB?): 4000 lbs, 3.70 final, 17.5hp @ 50mph
Land Cruiser (wagon):4500 lbs, 3.70 final, 16.5hp @ 50mph.

I appreciate your skepticism, but the EPA test HP is that which corresponds
to the actual road load figures for 50mph, so although they test with the
vehicle stationary on a chassis dyno, the test HP is that required to push
the vehicle down the road... or is supposed to be <g>.

On the off chance that it might inspire some measure of greater confidence in
the EPA numbers, consider the following reality checks based on the *real* world:

Paul Wallace posted:

         My '91 S10 at 120vdc draws about 75-100 amps on level ground at
         55mph in third gear.  Any slight rise in the terrain puts me over
         100 amp and accelleration requires about 150amp.  My truck is
         about 4000lbs.         Hope this helps.         Regards,
         Paul Wallace

120V@75-100A= 9-12kW (without accounting for voltage sag).  This is about
12-16hp *input* to the motor, and would reasonably be expected to deliver
about 9.5-13hp at the "crank" (80% efficient motor), or 8.6-11.5hp at the
wheel (90% efficent drivetrain).  The EPA road load HP for a '90 S10
(3125 lbs) is 10.6hp @ 50mph.  Looks pretty damn close to me.

John Wayland posted:

      The Red Beastie, a '95 Toyota extra cab truck, is a real porker,
weighing in at 5000+ lbs., and is also a 120 volt system. On the trip to
Seattle, it typically drew from 112 to 120 amps to move along at 50 mph
on level ground, and more to run at 55 to 60 mph, but certainly not as
high as 200 amps.See Ya.......John Wayland

120V@112-120A = 13.4-14.4kW (again, without accounting for voltage sag),
which is about 18-19hp *input* to the single 9", so perhaps about 15hp
at the "crank" (80% efficient), and about 13.5hp at the wheel (90% eff.).
The EPA road load HP for a '95 Toyota 2WD PU (3500 lbs) is 12.6hp @ 50mph
(including A/C, which appears to be about 1hp for the Toyota).  Again,
reality appears to be in fairly close agreement with the EPA (especially
considering the 1500+ lbs of additional weight in the Red Beastie).

Plug the "Red Beastie" into Uve's calculator (aerodynamic small truck,
Cd=0.42, A=24 ft^2, total vehicle weight 5000 lbs, no wind, no incline,
rolling resistance=0.015, brake & steering drag=0.003) and it predicts
22.9hp @ 50mph... hmmm. <G>

Didn't you write that the truck was going to be used *on-road*?  If so,
then jacking it up, adding bigger, higher rolling resistance tires all
seem designed to make the thing even less practical to convert.

You might turn your buddy on to Optimas: with up to twice the cranking
amps of many typical starting batteries, he might get up to 20-25mph on
one!  I just stuck a YT in my van and it now *SPINS* over where it used
to *turn* over.

Good luck with your conversion!

Cheers,

Roger.

 -----Original Message-----
From:	Byars, William [SMTP:wbyars@MPCProducts.com]
Sent:	Tuesday, November 30, 1999 7:01 AM
To:	'Roger Stockton'; 'ev@listproc.sjsu.edu'
Subject:	RE: my very heavy and lossy EV LandCruiser idea... :-)

Roger,
	Interesting numbers. The '78 LandCruiser is essentially similar to
my '79 LandCruiser, if both are SWB, though I've got 3.73's and it has
4.11's. 12.7hp might push it to 50mph... In a vacuum!

[snip]

Truly a worst-case scenario for conversion. :-) And I'm going
to add bigger, less aerodynamic and higher rolling resistance tires, etc. as
well as sticking the axles out into the wind more and whatnot with the lift.

	Only information I have on Electric LandCruisers is from the starter
already in the vehicle. On a mid-70's FJ-40, if you take the spark plugs out
and drop in a nicely charged ICE starting battery, you can get it up to
about 15mph in 4th gear. :-) Buddy of mine in Ohio has to move around a few
carcasses once and a while, so he learned that trick one day...