rec.autos.simulators

I read it, and now I'm more confused than ever...:-)

Naa, good read, can't argue one way or the other really, but it's always
nice to witness a good discussion where people don't start calling each
other names as soon as they're not in 100% agreement :-)

Beers and cheers
(uncle) Goy

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  No it isn't you Noweegiean bassoon...name calling shows a true level of
intellegence....:)
dave henrie

I have a *serious* problem with the esses at Mexico(GPL).  I've gone from being
right on a car's gearboz at the beginning to him being out of SIGHT at the end.
 I think the same thing should happen at Zandvoort, but the effect isn't that
bad.  At Mexico I simply can't get through the turns with ANY kind of speed.
And, I struggle to run 1:53 laps... :(

Eldred
--
Dale Earnhardt, Sr. R.I.P. 1951-2001
Homepage - http://www.umich.edu/~epickett
F1 hcp. +16.36...Monster +360.54...

Never argue with an idiot.  He brings you down to his level, then beats you
with experience...
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Just a minor terminology point (since that seems to be the
subject at hand ;-) -

"Braking efficiency" as I've heard it is a measure of how
close to ideal brake distribution the car is, in some particular
situation.  At 100% braking efficiency, brake torque distribution
*matches* the dynamic weight split of the car and deceleration
(in G) is equal to the coefficient of friction.  Lower values,
IIRC, are defined by [decel / mu].

This does suggest that the brake balance is further back than
ideal... (I did ask, some time ago, if anyone knew a CG height
for the cars so I could calculate a ballpark ideal brake
distribution; but no luck).

I know of two situations where throttle is used against brake.
Actually, no, make that three.  The third is in rallying with
FWD cars in particular, where LFBing is used instead of the
handbrake to cause oversteer (exactly the same process as
we're discussing, but the other way round).

The other two are:

 1) to keep a turbo car "on boost";
 2) to maintain airflow through an exhaust-activated diffuser,
    and hence gain ground-effect downforce.

Excellent thread btw - most enjoyable to read!
Jonny

On Mon, 15 Oct 2001 21:17:37 +0100, "Jonny Hodgson"

Sounds good to me Jonny, a point I eludued to in my post
was that getting maximum efficiency from the brakes (via all
four tires) is virtually impossible as you rarely get equal
weights and grip levels side to side (they are often very
close of course but rarely equal). Also you can only really
set your ideal brake balance for one type of corner (uphill,
downhill or flat).

It's not a hugely important point as threshold means the
maximum retardation of the CAR, not really of the brakes
or tires. Often you will see an unloaded front-wheel lock
up under brakes, this is well past threshold for that tire
but overal is probably pretty much at the threshold of maximum
retardation.

I'm afraid I don't know but I will try and find out for you from
the Setups forum run by Tifosi, or maybe George M. Smiley
would know, he is pretty clued up on this stuff.

Very true and certainly number 1) is very heavily used (or
at least was, I've not noticed it as much with modern day
Turbo cars, maybe modern technology avoids this.

Very glad you are enjoying it Jonny, thought it was just me
and Tom for a while. Thanks for taking the time to read
and respond.

Maxx

Eldred,

The Esses at Mexico are really too tight to directly benefit from the
comfort brake approach. In fact the opposite is the case here.

The comfort brake is useful for the open "switchback" bends
of say Zandvoort and the Ring where you want to keep the
car from swaying side to side. At Mexico you really need to
use this "swaying" to get the back to come around a little,
allowing you to carry a little more speed into the corner (the
back coming arouind will use the angle of the car to slow you
further - and better than straiight line braking)  and get on the
power a touch earlier on the exit. Similar to Rally-Style tarmac
driving.

Maxx

Some of us barflies enjoy eaves-dropping on interesting stuff like
this. ;)

Cheers,
-pierre

One thing I should correct is that instability in braking is not really
due to incipient rear lock, as I originally said.  That implies that you
can go all the way out to the verge of rear lock and still be stable,
and that's not true.  Thinking about it some more, as you approach that
point the ability of the rear tires to support lateral forces gets
steadily less, and of course there are always lateral forces due to
assymetry of the track/car/brakes/tires/etc.  Plus, you don't need to
lose traction to feel unstable, as soon as you start getting noticeable
slip angles due to those small lateral forces the car will feel
unstable.  So the point at which the car gets unstable will probably
come somewhat before the point of rear lockup.  Also, in addition to
using throttle and brake to stabilize the car in turns, adding a little
throttle in straight line braking in response to a slight yaw, instead
of relaxing pressure on the brakes, is probably a more effective
correction and will also probably cost you less time.  So again, my
point is that I think there are valid physical reasons why throttle +
brake works in GPL.

I've never been able to get into a rhythm at Mexico.  In the esses, I only get
understeering.  Something about that track(among others) doesn't suit my
driving style.  I really wish there was a way to 'start over', as I don't seem
to be able to 'unlearn' what I've screwed up in learning.

Eldred
--
Dale Earnhardt, Sr. R.I.P. 1951-2001
Homepage - http://www.umich.edu/~epickett
F1 hcp. +16.36...Monster +360.54...

Never argue with an idiot.  He brings you down to his level, then beats you
with experience...
Remove SPAM-OFF to reply.

Oh yeah, well your father was a hamster and your mother smelled of
Elderberries....now go away before I taunt you a second time

Beers and cheers
(uncle) Goy

"The Pits"    http://www.theuspits.com/

* Spam is for losers who can't get business any other way *
"Spamkiller"    http://www.spamkiller.com

Eldred,

You may have heard (or tried) this suggestion before but try
switching off the racing groove at Mexico. It's not accurate
and try as we all do, it's hard not to get sucked into following
it.

Not sure where you are with diff at the moment but the
Lo/Hi/Few diff workd great here. If you don't want to do
that, maybe try adn get some more mechanical o/steer
going. Use GPLRE to add 30-40lbs to the rear wheel
rate.

Might Help.

Maxx

I'm sure I heard that before, but I'm not sure it was directed at Mexico...
I'll try it.

I'm still using Alison's setups for whichever chassis I happen to be driving at
the time.  I don't even think I've *used* GPLRE.<g>

Eldred
--
Dale Earnhardt, Sr. R.I.P. 1951-2001
Homepage - http://www.umich.edu/~epickett
F1 hcp. +16.36...Monster +360.54...

Never argue with an idiot.  He brings you down to his level, then beats you
with experience...
Remove SPAM-OFF to reply.

The drivers jerk the car around in a way that, some years ago, would
have caused them to be labeled an amateur, and would likely have sent
them flying off the track in many cases.

I couldn't help but note that the Japanese race was like watching the
car in Automan (cheesy American sci-fi from the 1980s) go down the
street.  It's almost like they have no inertia at all.

I'd also like to see a lot less emphasis on pit strategy.

Wouldn't it be amazing to be able to see, again, things like Jimmy
Clarks comeback at Monza in 1967.  It just can't happen now... :(

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