Re: Sparrow II

["Tim Clevenger" <tclevenger@hotmail.com>]

>From :    "Peter VanDerWal" <peterv@peoplepc.com>
To :    <ev@listproc.sjsu.edu>
Subject :    Re: Sparrow II
Date :    Mon, 30 Jul 2001 10:22:34 -0700

Hi Peter,

>I was doing a little surfing on this subject earlier.  Did you know that
>untill earlier this year the NHTSA didn't perform ANY kind of roll over
testing?  When they proposed it, the auto manufacturers fought tooth and
>nail to prevent it.  They are working on a method to do dynamic testing, 
>but
>for right now they are doing static testing (basically calculating the CG 
>vs
>track width) and rating the cars with one to five stars based on how
>dynamically stable they are.  Only one car, the Honda Accord, has recieved
>five stars so far.

The NHTSA got a lot of heat when that test was finally released because, 
unlike the other "star" tests, this test doesn't indicate the potential 
survivability of the rollover--just the chances of it.

>Blacking out from only 6Gs?  Hmm, perhaps they shouldn't be racing ;-)

This issue happened at one specific track where they banked the turns to 
increase speed.  Turns out that some of the drivers remember entering the 
corner... and then waking up halfway down the next straightaway.  Turns out 
that the combination of heat in the car, exhaust gases picked up while 
drafting the car immediately ahead and G-forces conspired to knock out 
drivers in the corners.  (I believe one of the motorcycle racing 
organizations also experienced blackouts on this track--they now use 
restrictor plates to keep the speed down to a manageable level.)


>Whether it makes sense or not it happens.  Why, I don't know.  But I have
>seen it on numerous occasions in stock car racing.  Normally the vehicle
>gets tapped or something and starts to slide sideways.  It will slide for
>quite a ways sideways (with nobody near by) and then suddenly flip and 
>start
>to tumble.

I believe it's because the car's shape produces adequate downforce while 
cornering to prevent those incidents.  Perhaps the "tap" from the side upset 
the suspension enough to overcome the downforce that is also reduced by 
diminishing speed as the car slides/spins.

>I have never said that you can't roll a sparrow, just that it won't happen
>in normal driving (and it won't happen in fairly agressive street driving).
>Passenger cars can and do roll over, it just takes the right circumstances.
>When they do roll over deaths and severe injuries frequently occure.

What is "normal driving?"  In vehicles that have been found to have higher 
rollover rates (one of which is I believe a recent Isuzu truck), they're not 
rolling over on the 300 ft skidpad; they're rolling over in an emergency 
evasion maneuver (sharp right to get over a lane to get around the obstacle, 
then sharp left to keep it in the next lane.)  That may not be a "normal 
driving" maneuver, but that's the one time that I don't want my vehicle to 
roll over.

Body roll is a function of grip, suspension stiffness and CG--the more grip 
you have, the easier the rollover.  The person who was chasing a course in 
an ambulance probably didn't roll over because the tires slide before the 
vehicle can lean too far over.  Put some racing slicks on there and see how 
quickly it tumbles.

>After the sparrow bounced four times on three different sides it came to
>rest lying on the door.  The driver climbed out through the window with 
>only
>minor bruises.
>While not conclusive this would seem to indicate that should you roll a
>sparrow, at least it seems to be a fairly safe vehicle to do it in.

Amen to that.  All of those deaths and injuries are pretty much unavoidable 
in an SUV because you have 5,000 pounds of metal pushing down on the roof.  
(I wonder if even a racing rollcage would save your skin.)  I would feel 
fairly comfortable driving a Sparrow with that damage statistic in mind.

>Making the Sparrow completely roll proof would require a complete 
>re-design.
>Perhaps that is what he is doing with the Sparrow II.

I certainly hope so.  I'd hate to see states take notice and start 
regulating three-wheel motorcycles because of rollovers.

>Mike Corbin is not in this to make a quick buck.  He is concerned about the
>enviroment and building the only kind of vehicles he can with his 
>resources.

I read something interesting about the Merlin.  It will be using a custom 
V-Twin engine... that's ULEV compliant.  Motorcycle engines (AFAIK) are not 
yet regulated in their emissions, so he could have built that engine any way 
he wants.  I'm impressed that he took the high road in that aspect--if it 
has to be an ICE, at least it's a cleaner ICE... maybe he'll sell those to 
folks looking to hybridize their own cars.

>I suspect he got to the point where it was either give up on the idea and
>bankrupt Corbin Motors, or sell what he had.
>The Sparrow is not perfect (what car is?) but he IS building and selling
>them and making improvements as he goes along.

Alas, the Microsoft Way.  (Hey, at least he's only doing it by NECESSITY.)  
:-)

>As far as I can tell, at this point he is the ONLY manufacturer of fully
>enclosed EVs that are actually available for purchase by individuals.

I wish there was some way around the four-wheel certification process--or at 
least a way to make it affordable for entrepreneurs.  I think the Sparrow 
concept in a two-seat four-wheeler would sell even better than the Sparrow.

Tim


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