rec.autos.simulators

GPL - stability under braking

Hick

GPL - stability under braking

by Hick » Tue, 10 Sep 2002 17:06:58

I'm getting my lap times down at Silverstone, but in a six car AI race
I can't stay with the two fastest cars. One problem I've noticed is
that the AI cars brake later than me on most corners, and manage to
stay on the track. If I try to brake later (which means I have to
brake harder), I find the front end of the car starts squirming all
over the place. Usually results in stepping on to the grass followed
by a spin. Is this a brake bias problem? How can I retain car
stability with later/harder braking?

Thanks.

--
Cpl Hicks

Kevin Clar

GPL - stability under braking

by Kevin Clar » Tue, 10 Sep 2002 18:19:57


> I'm getting my lap times down at Silverstone, but in a six car AI race
> I can't stay with the two fastest cars. One problem I've noticed is
> that the AI cars brake later than me on most corners, and manage to
> stay on the track. If I try to brake later (which means I have to
> brake harder), I find the front end of the car starts squirming all
> over the place. Usually results in stepping on to the grass followed
> by a spin. Is this a brake bias problem? How can I retain car
> stability with later/harder braking?

> Thanks.

> --
> Cpl Hicks

Try adding a touch of throttle when you brake.
And/or moving the brake balance back a little (higher %)

Kev

Malc

GPL - stability under braking

by Malc » Tue, 10 Sep 2002 19:57:21


If the front is unstable, this might be a result of excessive negative
camber, so you could try reducing this & stiffening up the anti-roll bars to
compensate, but if you're not to comfortable with changing the setup or
can't feel the difference, just concentrate on coming off the brakes more
smoothly, and if you have split axis pedals, do as Kevin suggests and add a
little throttle to help stability. It works really well, but you need to be
smooth and consistent, speed will come with practice.

What's your brake bias set to at the moment? Are you using the standard
setups?

Malc.

Jan Verschuere

GPL - stability under braking

by Jan Verschuere » Tue, 10 Sep 2002 20:03:22

"Kevin Clark" wrote...

> > <snip>
> Try adding a touch of throttle when you brake.
> And/or moving the brake balance back a little
> (higher %)

Putting the brake balance back, i.e. towards the rear, is actually a lower %
number.

Jan.
=---

Kevin Clar

GPL - stability under braking

by Kevin Clar » Tue, 10 Sep 2002 21:46:15


> "Kevin Clark" wrote...

> > > <snip>
> > Try adding a touch of throttle when you brake.
> > And/or moving the brake balance back a little
> > (higher %)

> Putting the brake balance back, i.e. towards the rear, is actually a lower %
> number.

Oh well, I meant make the % higher. 57 or so is pretty stable.
Jan Verschuere

GPL - stability under braking

by Jan Verschuere » Tue, 10 Sep 2002 22:08:17

"Kevin Clark" wrote...

> > <snip>
> Oh well, I meant make the % higher. 57 or so is pretty
> stable.

Indeed, putting the brake balance forward stabilizes the car as there's less
chance of locking the rear wheels up. Understeering off the track is also no
fun whatsoever, though. ;-))

Jan.
=---

John Pancoas

GPL - stability under braking

by John Pancoas » Tue, 10 Sep 2002 23:00:20

  Also keep in mind, the AI has a whole different physics model(or lack of)
then you do.

  There's numerous things they can do, you'll never be able to do.

John


Jonny Hodgso

GPL - stability under braking

by Jonny Hodgso » Wed, 11 Sep 2002 02:08:22


>   Also keep in mind, the AI has a whole different physics model(or lack of)
> then you do.

>   There's numerous things they can do, you'll never be able to do.

Also bear in mind that the 'Global Hype' thing means that you're
not *supposed* to be able to beat the top couple of AI cars...

Jonny

Haqsa

GPL - stability under braking

by Haqsa » Wed, 11 Sep 2002 08:38:41

Some good suggestions were posted, but I would like to suggest a
different tack entirely.  I have done some calculations on GPL
suspension deflections under different loads, and there is no doubt in
my mind that under heavy braking, with the default setups, you are
hitting the bump ***s hard.  This causes the front tire load to go
too high and is one cause of squirming.  I would suggest first just
lowering the front bump ***s to the minimum and seeing if that feels
any better.  If it still feels squirrelly, raise the front spring
stiffness one notch.  On most of my setups I have lowered front and rear
bump ***s to 1 inch, and if that causes me to hit the ground I raise
the ride height instead of the bump ***s.


The Carvalho Famil

GPL - stability under braking

by The Carvalho Famil » Wed, 11 Sep 2002 12:57:38

Similarly, there are things you can do that they can't.
Also in your setup, check to see if it's symmetrical.
Jim


>  Also keep in mind, the AI has a whole different physics model(or lack of)
>then you do.

>  There's numerous things they can do, you'll never be able to do.

>John



>>I'm getting my lap times down at Silverstone, but in a six car AI race
>>I can't stay with the two fastest cars. One problem I've noticed is
>>that the AI cars brake later than me on most corners, and manage to
>>stay on the track. If I try to brake later (which means I have to
>>brake harder), I find the front end of the car starts squirming all
>>over the place. Usually results in stepping on to the grass followed
>>by a spin. Is this a brake bias problem? How can I retain car
>>stability with later/harder braking?

>>Thanks.

>>--
>>Cpl Hicks

John Pancoas

GPL - stability under braking

by John Pancoas » Wed, 11 Sep 2002 14:24:51

  Really ?  What is that ?  Not being a smartass, honestly can't think of
any thing.

John



Similarly, there are things you can do that they can't.
Also in your setup, check to see if it's symmetrical.
Jim

  Also keep in mind, the AI has a whole different physics model(or lack
of)then you do.  There's numerous things they can do, you'll never be able


I'm getting my lap times down at Silverstone, but in a six car AI raceI
can't stay with the two fastest cars. One problem I've noticed isthat the AI
cars brake later than me on most corners, and manage tostay on the track. If
I try to brake later (which means I have tobrake harder), I find the front
end of the car starts squirming allover the place. Usually results in
stepping on to the grass followedby a spin. Is this a brake bias problem?
How can I retain carstability with later/harder braking?Thanks.--Cpl Hicks

Dave Henri

GPL - stability under braking

by Dave Henri » Wed, 11 Sep 2002 15:44:45


    Drafting is the first thing that comes to mind, you benefit from
following other cars, the AI do not.
dave henrie

Hick

GPL - stability under braking

by Hick » Wed, 11 Sep 2002 16:43:12

Some good suggestions to try there. But are you saying it's impossible
to beat the top AI cars? They are certainly much faster than me.

--
Cpl Hicks

Malc

GPL - stability under braking

by Malc » Wed, 11 Sep 2002 18:50:35


As a general rule, the top AI will always be very hard to beat, but not
impossible. They use your previous best times for that track as an
indication of how fast they should go, but I don't think this changes during
the race, so if you've improved, you should be able to beat them.

I wouldn't worry too much about beating the AI, they are designed to try to
beat you, but mainly to prepare you for the online races. Although they
don't use the same physics as you, the line they follow and their braking
points should be good enough that you can learn from them.

Can you give an idea of the track/laptimes you're doing? Can you
consistently do 1:30 laps at Monza, for example? I can't find you on
GPLRank.

Malc.

John Pancoas

GPL - stability under braking

by John Pancoas » Wed, 11 Sep 2002 22:56:40




> >   Really ?  What is that ?  Not being a smartass, honestly can't think
of
> > any thing.

> > John

>     Drafting is the first thing that comes to mind, you benefit from
> following other cars, the AI do not.
> dave henrie

  Ok, thanks Dave.  Of course, when they can brake a few seconds later than
you going into the next turn, kind of defeats your draft :)

John


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