Yup, I got the answer. Nice video. You were driving, so it's your
fault. The car doesn't handle well, and you didn't handle the
cantankerous car well either. It's one of those things where you
have to drive whatever is put in your hands, and fix the handling
problem later.
It starts in the first turn at the 8-second mark when you get the LR
tire off the ground, followed immediately by oversteer and squeal
from the overloaded RR tire. You caught that one, tturned the
steering wheel quickly right to keep the nose going in the right
direction, and got your foot right back on the throttle to keep it
straight. But you should have gotten the message from that
trick. On the next turn you got the same thing at the 38 second
mark, a little body roll, LR tire up, oversteer, and RR tire squeal
as it goes sideways. You caught that one too, turned the steering
wheel quickly right to keep the nose going in the right direction,
but you over did the steering correction, didn't bring the wheel back
soon enough, and didn't put the throttle down, so you got immediate
and accentuated oversteer in the other direction (fish tail). When
that gets out of hand you're going backward, and the game is over.
You have a real quick autocross car there that will turn in quick and
oversteer on demand, but that's not the fastest way around a long
curve. What you need is more front sway bar (or less rear sway bar)
intending to keep the inside rear tire on the pavement to prevent
overloading the outside rear tire. If you over do the front sway bar
you can end up with understeer and push in the corners, also not the
fastest way around the track. For road racing you want near neutral
steering for the highest speed in a long constant radius turn. Then
lifting off the throttle makes it turn in better at the entry point,
and back on the throttle kills the oversteer and drives the front end
to the outside of the curve. (Just don't step too hard on the
throttle when one rear tire is off the ground).
Barney Gaylord
1958 MGA with an attitude (and a house full of autocross trophies)
http://MGAguru.com
At 01:41 AM 6/17/2011 +0930, Eric Erickson wrote:
>I keep studying this video and I am really not quite sure that my turn into
>this corner caused this incident.
>
>It is the third lap I have run at this racetrack since 2006 - so I was
>certainly out of practice, but to have the rear tyres let go like that was
>really unexpected.
>
>Any thoughts?
>
>http://www.youtube.com/watch?v=Y7eaUaoP-ME
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