Here's what I learned driving low torque, high RPM, RWD cars. You
hit those brakes early (but hard and briefly) so you're already
off the brake (and maybe on the gas) about the time you start to
turn the wheel for the corner. You do lose some time entering the
turn, but you gain a lot more coming out -- if there is a
straight you can use it on. But even if there is not, on tight
turns, 3rd gen '7s will plough like a pig (understeer) if you try
to corner under braking -- which is the opposite of when they do
at high speed. Some power induced oversteer will offset that, but
you need to get on the gas _early_ to get that because all the
torque's at high RPM. Hit the gas too late and you'll come
walking out of the turn with the accelerator on the floor,
wondering why the car isn't moving. Get on the gas early, and
you'll blast through the turn so fast you'll have to unwind the
wheel early to control the back end.
Does that sound like a major late apex sort of line? I suppose it
is but it works for me and it sure _seems_ like that's what I'm
doing, and it's what RX-7 guys way more experienced than I am
taught me at the autocrosses and classes I attended in the past.
I used to think this was peculiar only to 3rd gen '7s, but I
drove my friend's 911 recently and it felt similar. Then I just
drove a '99 Miata and it also felt good that way. So now I'm
suspecting it's a good general technique for RWD cars. However
I'm not sure it'll work with FWD, because it's hard to accelerate
and turn at the same time with FWD. Maybe it will, I never tried
it.
I think cars with lots of low end torque are generally the same,
but more forgiving if you do it differently. Stomp on a big V8 at
any time, any gear and it blasts off right _now_. Makes things a
lot easier.
But then you also have to think at least two turns ahead. How you
_choose_ to drive through the turn in front of you, usually
determines how you _must_ take the next turn. That's why walking
the course in advance and looking ahead helps more than anything
else you can do. If you're not looking ahead, you're just
reacting to where the car already is -- it's only when you're
looking ahead, mentally staying in front of the car, that you can
go where you want to be. And that piece of advice works for
anything -- FWD or RWD, no matter how many wheels or what kind of
engine.
James Creasy wrote:
>
> i didnt read the article, but it is obvious that late apexing has less
> benefit in autocross because the straights are so short compared to a road
> race track. remember to late apex you go slower than a geometric apex on
> the first part of the turn, hoping to make it up by more speed all down the
> straight. in autox there another turn awaiting you shortly, so the idea of
> a good line for a particular turn is affected greatly by what comes before
> and after.
>
> ive autoxed a FWD car with excellent handling and power, a RWD torqueless
> car with good handling, and a RWD monster car with ... hey i dont need no
> stinkn handling, ive got TORQUE! hehe and for the most part i think the
> fast way is very similar in all of them: get on the gas smooth, brake late
> and smooth, trail brake, use all the track, and carry maximum speed through
> the corner while looking ahead and linking it smoothly with the next corner.
> be smooth and look ahead. my advice is not to get too worked up about
> differences in cars until you can reliably execute basic technique properly
> (i cant yet).
>
> comments?
>
> -James "torque poisoned" Creasy
> President, BAPOC www.klio.net/probe
> FFR Cobra #1630 www.klio.net/cobra
>
> -----Original Message-----
> From: Jeremy Bergsman <jeremybb@leland.Stanford.EDU>
> To: ba-autox@autox.team.net <ba-autox@autox.team.net>
> Date: Thursday, May 04, 2000 2:02 PM
> Subject: best line
>
> >Could people comment on the learning to autocross article in the recent
> >Sport Car? My question concerns the advice to drive the shortest path
> >through the course and concentrate on the slowest turns rather than
> >approaching the turns like in road racing where you will try to increase
> >exit speed before the straights. To what extent does this decision depend
> >on your car's acceleration/handling mix?
> >
> >Thanks.
> >--
> >Jeremy Bergsman
> >jeremybb@stanford.edu
> >http://www.stanford.edu/~jeremybb
--
Michael R. Clements
mrc01@flash.net
We must make clear that communism and the governments it now
controls are enemies of every man on Earth who is or wants to be
free.
-- Barry Goldwater
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