Track lines on various cars: WAS Delrin or Poly bushings? Worth it?

Huw Powell audi at
Wed Aug 18 18:31:30 EDT 2004

> I disagree- the proper line for track and street driving (not autox) 
> is basically the same, regardless of the car. Now in terms of 
> throttle and brake application, that would differ between various 
> cars and their individual handling characteristics.
> I don't see how the proper line for a 951 would be any different than
>  for a Coupe GT or an A4. The fastest way through a corner is the 
> shortest, unless there are extenuating circumstances that require 
> modification of that principle

Well, I have to say first that I haven't got a clue what I'm talking
about, never done any driving schools, or seen any diagrams, etc., of 
turn lines, apexes, etc.

But, I'll join in anyway!  One, the fastest line through a curve is not 
necessarily the shortest path - it would be one that distributes the 
velocity curve (on a graph) so it has the greatest area under it, which 
probably means slowing down as late as possible and accelerating as soon 
as possible, around some ideal point on the curve (road curve) defined 
by the track and the car.

Two, at Mt. Washington a few years back I was up at the 2/3 point, 
watching everyone go through 3 or 4 curves.  After I while, I noticed 
that different cars took a very different approach to the curve as they 
disappeared (last curve before a straightaway).  There were too few rear 
engined Porsches (or I didn't recognize them) for me to see them as a 
"category", but what was fairly obvious was that there were three very 
different ways to take the corner - divided between rear wheel drive, 
front wheel drive, and the quattros.

That is not to say that the apex was in a different place for them, 
though I suspect it was.

Finally, anyone know where thre might be really good diagrams and 
explanations of track lines, apex points, etc., out there on the www?

> I know all of this, obviously you cannot drive every car the exact 
> same way, however I disagree with your contention that you would want
>  to turn in earlier with a better handling car- you turn in so that 
> you clip the apex, not before, not after.
> I think you are confusing entry/exit speed with turn-in point.

Huw Powell

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