what i say is "pay the price BEFORE the apex"
the "price" i am referring to is giving up momemtum.
that is, since you have to slow down (do enough slowing down so once you get
on the gas, you dont have to lift) do ALL of your slowing before the apex.
it is more costly to lift a little coming out of a turn than to brake a
little too much going in.
you must trailbrake in autocross, otherwise you will get understeer at
corner entry.
the corner you describe sounds like a decreasing radius corner, and
typically you can enter much more deeply than it looks at first, then trail
brake and let the car scrub to the apex. on my car, i will let (or induce)
the rear to come out a little to help scrub. better handling cars you can
just steer tighter to the apex and the suspension take care of itself.
cars with ABS are subject to an understeer condition in this type of
maneuver and you will need to module the brakes off the ABS to reduce
understeer. (there is torque about the center of gravity due to the way the
ABS affects the steer characteristic under lateral weight transfer) i
noticed with while autocrossing a miata a few weeks ago into a decreasing
radius turn.
-james c
OSP #74
----- Original Message -----
From: Giles Douglas <giles@vy.com>
To: 'Clifford Richardson' <the_brain7@hotmail.com>;
<ba-autox@autox.team.net>
Sent: Friday, August 17, 2001 3:07 PM
Subject: RE: braking...
> On RWD you can use the throttle to rotate the car more. On FWD the
throttle
> just causes understeer.
>
> If you break entering a turn, you're really trail braking. This enables
you
> to rotate the rear of the car somewhat (useful on a FWD or AWD platform)
and
> get around the corner quickest.
>
> Most of the textbooks will recommend you do most of your braking in a
> straight line then gradually lift off the brakes entering the corner
> (effectively trail braking), and then being to accelerate when the car is
> pointing in the right direction and unwind slowly.
>
> The older opinion used to be that braking had to be done in a straight
line.
> Of course, it was eventually figured out that this school of thought was
> wrong, and you can shave much more time by braking into the corner
somewhat.
> However, it should be noted that there is more time to be made by getting
> the entry/apex/exit acceleration whilst unwinding right than there is by
> being perfect on the brakes (time spent slowing versus time spent
> accelerating).
>
> It sounds like your second approach was better. Given time, you can
perfect
> the braking so that some of your slowing is done whilst the car is turning
> somewhat (of course, bear in mind that if you're using 100% of your
traction
> to brake, you can't turn, so you have to lift a bit off the brakes.
Traction
> circles and all that jazz]
>
> Of course, this is much easier on a wide open track on an autox course, so
> I'm sure someone else can give way better advice ;-)
>
> Giles
>
> -----Original Message-----
> From: owner-ba-autox@autox.team.net
> [mailto:owner-ba-autox@autox.team.net]On Behalf Of Clifford Richardson
> Sent: Friday, August 17, 2001 2:22 PM
> To: ba-autox@autox.team.net
> Subject: braking...
>
>
> I was at the event at Mather this past Sunday. The course was the longest
> I've ever been on (4th event and counting) and a lot of fun. I posted
> horrible times, but I made up for it in the fun runs. There was this
> especially deceptive left turn towards the last stretch that caused a
number
> of drivers to spin out. It starts out mild and got tighter b4 curving back
> to the right. I can extremely close to stopping my car in that turn to
avoid
> hitting a cone during one of my official runs. That notably cost me more
> than the one second I would've had if I'd just hit the damn
cone...might've
> taken more than just one though...
>
> Ok, now on to my point/question; on my second fun run, I shaved off 2.6
secs
> of my best official run. One of the things I did differently was braking
> HARD right before entering that wicked turn. It allowed me to go through
the
> turn much more gracefully and accelerate out of it. In previous runs, I
was
> fighting for control all the way through the turn and was going awfully
slow
> by the time it straightened out. My question to you veterans out there: on
> sharp turns where braking HAS to be done, is it better to brake BEFORE
> entering the turn or brake "as needed" during the turn? (both on street
and
> racing tires)I understand that because of the nature of my tires and
> relatively low-torque on my car, my options might be slightly different.
Oh
> also, is the braking behavior different with FWD vs RWD?
>
> My question may be a bit vague, but that's pretty much the best I can
> explain it for now. I welcome any comment in regards to braking. Thanks.
>
> -Arnold
> "Gee, Brain. What are we going to do tonight?"
> "Same thing we do every night, Pinky. Try and take over the world!"
>
>
> _________________________________________________________________
|