rec.autos.simulators

by **Matthew V. Jessic** » Wed, 15 Apr 1998 04:00:00

Agreed,

- Matt
(GPL must have lot of bumps modeled... no wonder I keep
spinning off! :):)

by **Matthew V. Jessic** » Wed, 15 Apr 1998 04:00:00

> But then I guess this understeering could also create forces that
> fight back the wheel's movement. But having driven a motorcycle I can
> tell you that at high speed the rotational inertia of the wheel cannot
> be neglected.

When a motorcycle leans right, the rotational inertia
of the wheel (pointing to the left) is rotated up
more toward vertical. This results in a precession torque
about the steering axis. (Big omega cross little omega
and all that stuff ;)

Cars get this too. For example when the wheel bounces
after a bump the camber will change with the suspension
motion. This camber change (change of the rotational inertia
vector) would require a steering torque to oppose the gyro torque.

The wheel rotational inertia, the torque to cause/oppose the
gyro precession and the precession are all at right
angles to each other. So leaning (cambering? ;)
the spinning tire is what causes gyro torques about the
steering axis.

- Matt

by **Byron Forbe** » Thu, 16 Apr 1998 04:00:00

> Well now I'm quoting myself... It doesn't get any better...

> I've tried setting linearity to full and what I experienced was worst
> than what it was before in terms of being everywhere on the track on
> straightaways... Just like I expected quite frankly.

> When you move this slider to the left, you decrease sensibility at the
> right and left extremities of your controller's movement, but you
> increase it near it's center position, and that's just what I was
> complaining about, the car being too nervous when you're driving in a
> straight line. I could increase non-linearity but then the problems
> move to the corners instead of straights, so anyway I'm going to have
> trouble with this option.

> I'd be one happy man if they'd include a "reduce with speed" style of
> slider... Maybe it can still happen, I hope so... And if it's there
> and you don't want to use it then you'll only have to set it to zero,
> that's all...

What I meant was to move the slider all the way to the right. Another
thing that many find difficult about Papy sims is the excellent
modelling of body roll/weight transfer. Believe me, when you get used to
it there is simply nothing better and going back to most other sims will
feel arcadish and dead in comparison. I have been racing ICR2 for many
months now and so that's why the step to GPL was easy for me. The big
improvement from ICR2 to GPL is the brake and spin modelling which was
almost non existant in ICR2.

by **Byron Forbe** » Thu, 16 Apr 1998 04:00:00

> > For those who need more realism, try an experiment:

> ROFL! But all too true ;-)

> Personally I do tend to work out the limits in sims by deliberately
> pushing the car beyond them, but that's only because I'm impatient <g>

> The real test about all this stuff comes when we'll be racing online with
> realistic damage. Then it becomes a case of know exactly what your limits
> are and driving within them. I remember a 15 lap Sear Point race on TEN
> where I was a long way from being the fastest but won by a whole lap with
> only one other finisher <vbg>

> The main difference I've found with GPL compared to the other sims is
> that the limits really are just that. With the others it's a case of
> 'oops, a bit hot into that corner - no worries though, just back off the
> throttle and all I've lost is a tenth or two'. Not so with GPL and a lot
> of sim 'experts' are going to have to completely redefine their driving
> approach...

Yeah, especially the way the demo is setup you would think so. Even
VERY gentle touching of the brakes in a corner is a big NO NO (or even
just lifting off) but i'd guess the final version with adjustable setups
will cure this a little at least.

by **Antoine Renau** » Thu, 16 Apr 1998 04:00:00

On Tue, 14 Apr 1998 18:43:05 -0700, "Matthew V. Jessick"

>When a motorcycle leans right, the rotational inertia
>of the wheel (pointing to the left) is rotated up
>more toward vertical. This results in a precession torque
>about the steering axis. (Big omega cross little omega
>and all that stuff ;)

Well... erm... That's just what I was saying! ;o)

A. Renault

by **Doug Millike** » Thu, 16 Apr 1998 04:00:00

> > Which is why good forcefeedback will be a HUGE win. (However, by my
> > definition of "good", it's unlikely to be sold for anything less than
> > four figures USD.)
> Hi Jim, read this and had to comment, this is EXACTLY correct, people
> seem to have the misconception that FF in its present incarnation is
> worth having which you and I both know is not so :(!

> When and IF FF is ever developed to where it becomes of value as
> anything beyond "arcade game tricks" it is going to be expensive to
> implement.

I think I stuck my nose in the last time there was a discussion of good
force feedback here... I'd hope that you don't include the original Hard
Drivin' and Race Drivin' in the "arcade tricks" category. Those games had
a pretty darn good car model and good big motors behind the ff wheel. Some
of them suffered from a cheap switching power amp driving the motor (a
little bit of force-noise), but other than that I'm still impressed when I
play my Race Drivin'. Note that we couldn't make the force levels correct
for real race cars -- little kids use the arcades and it's not a good idea
to break the customer's arms when the car spins out...

To see what you can do with ff if you spend some money, come try our
Silicon Motor Speedway (1st site in Mall of America, next one in the
Chicago area in a month or so). More info on: www.lbet.com

-- Doug Milliken

by **Byron Forbe** » Thu, 16 Apr 1998 04:00:00

> > I'm not taking anything personal! It seems many of you are comparing
> > GPL to CART/F1 cars which is just nonsense. In GPL you have NO
> > downforce, grooved hard compound tyres and twice the body weight. Why
> > would you expect magnatraction? There are real race drivers here who say
> > the physics model is very impressive indeed. Have a read and have a
> > think about it.

> Hi Byron

> I`ve seen this several times now and have to ask, twice the body weight
> ?

> Where did that came from, it says on the info screen that all these cars
> weigh under 1200 lbs, which I find to be more or less in line with my
> own knowledge (limited) of this era, these were very small cars after
> all.

> Beers and cheers
> (uncle) Goy
> UncleGoy on TEN

> PS I "do" agree with you though :-)

Good point! So much for assumption :) It seems these things were more
high tech in the weight savings dept than I assumed. I was assuming that
most of the frame, engine, etc would have been steel but they obviously
has some good alloys at this point. It's not really all that long ago
come to think of it. I also just jumped to the conclusion that all the
carbon fibre, etc on the modern cars would make them approximately half
the weight. But as you point out, these are small cars. Now you may know
this Goy - I think I read or heard somewhere recently that todays F1
cars weigh in at 600kg (approx 1300lb) with a full fuel load and driver.
I noticed in the GPL teams screen that the cars were around 1100lb
(Start Line Weight). I just wonder what "Start Line weight" is exactly.
In any case, it seems the weights will be about the same and the 67 cars
may actually be lighter! Silly me :))

Once again, come to think of it, I think I came to this false
conclusion after driving GPL because the cars certainly seem to weigh
twice as much after all the other F1/CART sims :))

by **Jim Sokolof** » Thu, 16 Apr 1998 04:00:00

> If you don't want "drift" then just drive
> > slower.

> Thanks for the advice. I dont consider what happens in the demo
> 'drift' The fact that the driving model is TOO loose makes it closer
> to powersliding ala a rally car. But this isn't a BLACK\WHITE
> opinion, as I already told you. Papy went TOO far with their good
> intentions ...from watching 'The Movie' and Speedvision till I'm
> blue in the face, I'd say the demo drives about 20 per cent too
> loose. Now I didn't use a slide-rule to calculate that number, but
> only to tell you my opinion of how far outta' whack I think the
> model is.

Ever even consider the possibility that the drivers that you are
attempting to emulate are at least 20% "better drivers" than you are?
With more practice, and better immersion and physical feedback?

:-)

---Jim

by **Byron Forbe** » Thu, 16 Apr 1998 04:00:00

> snip touchy responses

> How do you think it should be then?

> How do I think it should be then? Well if the driving model were
> 'tightened-up' by mabey 20 per cent, I think it would add more realism
> and not subtract from it. The demo is a welcome change of pace from the
> many modern F1 games that are out, and that are due out. I like the idea
> alot! The ability to make setups in the final version will for sure
> help GPL in the area I think it could use help, so thats nice to know and
> to look forward to. But for now I'm sticking to my guns that the demo
> driving model is too loose, even for the era it portrays.

Something else comes to mind here. In the demo the tyres are always
at optimum temperature so I think that would account for excessive
oversteer since it has been my experience that front tyres normally run
cooler than the rears. This fact alone is not giving a clear picture of
the physics model. Other things we do not know are tyre pressures
(possibly to high), suspension settings, etc. But you may be right.
Also, another thing that is possible is that the drivers you see in this
movie are in race mode and being conservative and being as good as they
are, make it look easy too.

by **Matthew Knutse** » Thu, 16 Apr 1998 04:00:00

> > > I'm not taking anything personal! It seems many of you are
> comparing
> > > GPL to CART/F1 cars which is just nonsense. In GPL you have NO
> > > downforce, grooved hard compound tyres and twice the body weight.
> Why
> > > would you expect magnatraction? There are real race drivers here
> who say
> > > the physics model is very impressive indeed. Have a read and have
> a
> > > think about it.

> > Hi Byron

> > I`ve seen this several times now and have to ask, twice the body
> weight
> > ?

> > Where did that came from, it says on the info screen that all these
> cars
> > weigh under 1200 lbs, which I find to be more or less in line with
> my
> > own knowledge (limited) of this era, these were very small cars
> after
> > all.

> > Beers and cheers
> > (uncle) Goy
> > UncleGoy on TEN

> > PS I "do" agree with you though :-)

> Good point! So much for assumption :) It seems these things were
> more
> high tech in the weight savings dept than I assumed. I was assuming
> that
> most of the frame, engine, etc would have been steel but they
> obviously
> has some good alloys at this point.

They were aluminium monocoque chassis, and the alloys were ok, but the
reason they were so light, was that there was absolutely no concern for
safety. Those cars were killer rockets....The Loti, or at least one of
them, retired from the '67 Glen GP with broken engine mounts, the new
Ford/cosworth engine was a real jump up that year.

The min limit is 500, and that's where you'll find them:)

Start line weight is exactly what is says:)

Hehe, yup, great fun IMO. So are the others. It's getting pretty scary
good, methinks:))

See you online when GPL comes out!:)

Matt

--

Matthew Birger Knutsen
Cheek Racing Cars (http://home.sn.no/~kareknut)

"Racing cars is like dancing with a chainsaw"
-Cale Yarborough

by **Richard Walk** » Thu, 16 Apr 1998 04:00:00

Actually both cars suffered badly at that race - Jimmy Clark had rear
suspension failure and Graham Hill had a knackered gear box. But they
didn't retire: Clark won with Hill second!

Cheers,
Richard

by **Byron Forbe** » Fri, 17 Apr 1998 04:00:00

> Start line weight is exactly what is says:)

So full fuel load and driver included then? Dunno how this would
include driver since in the GPL game they give weights to the nearest
5lb.

by **Byron Forbe** » Fri, 17 Apr 1998 04:00:00

> Hi Byron. I liked what you said about the drivers being in a race-mode
> and therefore driving more conservative, thats a very good point that slipped
> my mind. ...you know, the driver Bandini(I think thats how its spelled) died
> in the Monaco GP in 67'. He burned to death. And I don't mean he died of smoke
> inhalation ..he 'burned' to death. Its really horrible. 'those daring young
> men in their driving machines'. My biggest problem is getting the demo to run
> without stuttering ..and not, being burned alive. It certainly puts things
> into perspective. Mark.

Stuttering? Bad frame rate?

rec.autos.simulators

GPL -- Still bloody Undriveable - Not Real!

GPL -- Still bloody Undriveable - Not Real!

GPL -- Still bloody Undriveable - Not Real!

GPL -- Still bloody Undriveable - Not Real!

GPL -- Still bloody Undriveable - Not Real!

GPL -- Still bloody Undriveable - Not Real!

GPL -- Still bloody Undriveable - Not Real!

GPL -- Still bloody Undriveable - Not Real!

GPL -- Still bloody Undriveable - Not Real!

GPL -- Still bloody Undriveable - Not Real!

GPL -- Still bloody Undriveable - Not Real!

GPL -- Still bloody Undriveable - Not Real!

GPL -- Still bloody Undriveable - Not Real!

GPL -- Still bloody Undriveable - Not Real!