Generally when someone says a car is tractoring it means the front end
is handling like a tractor. You don't have to look at the car on track
to tell this, you can tell by the wear pattern on the tires. Perhaps
he meant that. He might have meant two stroking (running too rich),
but I'd guess he was looking at your tires.
Tractors (as many experts on the this forum can tell you) before the
general use of 4WD had a lot of positive camber in the front wheels,
the purpose of which was to move the contact patch of the front wheel
to the inside of the turn, pulling the wheel to that side. If you've
ever driven an old tractor you know what that means, the tractor
lurches to the inside of the turn. Doing this decreases turning radius
and decreases turning effort. It also makes up for the narrowness of
the track a little bit by pushing the contact patch outwards and
compensates for the low amount of ackerman available (or needed) with
the wheels that close together. It also makes the tractor wobbly at
speed, but since "speed" is a relative thing, it's not that much of a
problem.
On a race car with radial tires and too little camber, or bias plies
and positive camber you get the same effect--the car tends to dive to
the inside of the turn and requires pressure against the initial turn
in to counter the effect. You can see the problem pretty clearly on
the tires--they will be feathered towards the inside of the car on the
outside edge of the tire. In extreme cases there won't be any wear at
all on the inside edge of the tire.
Good ol' NASCAR and dirt track boys prefer to talk in these terms even
though they know just as much about what they are doing as any fancy
pants at an F1 race. The call a car loose (dynamic oversteer) or tight
(dynamic understeer), they say it's plowing (understeer), bunching
(excessive toe), tractoring (pulling inwards on turn in), or pushing
( undesrsteer).
On Jul 27, 2008, at 7:26 PM, Barr, Scott wrote:
> <<Plowing? as in understeer?>>
>
> No, he wasn't talking about handling, but about the way the car was
> running in our paddock spot. From our angle in the paddock, he
> couldn't see how the car handles on track.
>
> As to why I didn't just ask him, good question - the first time, I
> thought he was joking. And the second time, it wasn't really the
> time to stop and chat.
>
> I'll certainly ask him when I see him in a couple of weeks.
>
> Scott
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