Never did like those vans. Wow! What a story, and glad you made it
through the whole ordeal.
As for explaining the physics of roll-over possibilities, I find I
don't speak that language (use of formulae) and prefer explanations in
English, though I will attempt to follow the math, to some extent. The
new cars such as the Focus, some Toyotas, etc., scare me, and why one or
two haven't rolled yet, to me, surprising.
The last car to roll over at an SFR event was a VW, I think, but it
really didn't relate to its CG, but more to an inappropriate driver
reaction. If push comes to shove, any car can roll, given worst case
scenarios. Accidents do happen, and autocross is NOT as safe as it appears.
--Pat Kelly
Bill Hamburgen wrote:
>
> Sorry to say I'm somewhat of an expert on rolling pre-Previa Toyota
> vans. I nearly died in a rollover of a really, really worn out short
> wheelbase Toyota van in 1994. Going 70mph on a main highway (Arusha,
> Tanzania-to-Nairobi), the driver hit a big pothole. Two attempts to
> correct the skid and over she rolled. Took almost three hours to reach
> the hospital and I nearly bled out. Emergency surgery, 2 units of Nairobi
> blood (proved AIDS-free, thank God!), and after 10 days, a $90k Lear jet
> ride home at my HMO's expense. More blood, more surgery. Took a while,
> but everything is working pretty well now. My life's big adventure.
>
> I don't think that van would have passed tech anywhere ;-)
>
> /Bill
>
> -----Original Message-----
> From: Derek Butts [mailto:pnc1@earthlink.net]
> Sent: Thursday, October 19, 2000 4:07 PM
> To: Bill Hamburgen
> Cc: ba-autox@autox.team.net
> Subject: Re: Vehicle eligibility...
>
> In fairness to this discussion the Toyota Van I drove had 175,000 miles on
> it
> with the original shocks and crappy tires. I think it was a 1989 with the
> narrower track and higher center of gravity. The Previa is a later model
> Toyota van with a wider track and wheelbase.
>
> Sorry, my mistake - the Previa does look like a turtle, though : )
> -Derek
>
> Maybe we should institute a policy that the Safety Steward test drives the
> proposed vehicle at speed and if it rolls they simply hand back the keys to
> the
> owner and say "this vehicle is not acceptable for Solo II" : )
>
> Bill Hamburgen 650-617-3329 FAX -3374 wrote:
>
> > I'd been holding off weighing in on this, but I can't any longer.
> > Derek Butts said:
> >
> > > I have driven this van before. We used to have one as a parts van.
> > > If autocrossed it will end up like an upside down turtle....
> >
> > I have both autocrossed my Previa and been up on two wheels in my GTI.
> >
> > My Previa is an Altrak, with a rear sway bar, good shocks, and slightly
> > lower than stock due to low profile tires (215/60-15). It handles better
> > than a lot of sedans. I autocrossed it once at an SFR event (at Alameda
> > NAS about 4 years ago) and my time put me in the top 80% of the entire
> > field. Beat a Porsche, a Vette, and a Tiger among others. Look it up.
> >
> > My GTI was running in ES on BFG R1s at another SFR event. My co-driver
> > sawed the wheel trying to catch a spin and got us up on two wheels.
> > I couldn't tell, but Katie Elder and other reliable witnesses said they
> > saw air under the tires. I did not like this. I lowered the car 1.25",
> > beefed up sway bars and moved to DSP. The car is now totally
> > uncompetitive, but is safer and a lot more fun to drive.
> >
> > What's the point? That vehicle/tire combos that roll with some
> regularity,
> > such as race rubber clad but otherwise stock VWs, BMWs, and various
> > econoboxes, are allowed to run events, but others that *may* be even less
> > prone to rollover provoke a knee jerk reaction like, "A Previa is not an
> > acceptable vehicle for Solo II"
> >
> > My suggestion: you can't easily measure CG during tech, but you can
> > measure outside dimensions. CG height can be conservatively approximated
> > as the midpoint between ground clearance (C) and height (H). Divide the
> > estimated CG height by the track width (T) and use that ratio as a
> > stability index.
> > C + H
> > ----- = stability index
> > T
> >
> > Pick a cutoff stability index that would exclude vehicles already known
> > to have a propensity to turn turtle (VWs, 3 series BMWs, etc).
> > And encourage vehicles over that ratio be excluded by the safety steward
> > on stability grounds, unless the vehicle is classed in the rulebook.
> > Perhaps my Previa could have been excluded on under this rule. So be it.
> >
> > Note that lowering a vehicle reduces both C and H. This correlates well
> > with what we all know intuitively.
> >
> > I'm not claiming this formula is perfect, but I think it's better than
> > excluding vehicles based on appearance.
> >
> > /Bill
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