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  #61  
Old August 21st 05, 04:43 PM
Steve Blankenship
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"Saltheart_Foamfollower" > wrote in message
. ..
> Exactly Bob.
>
> Anyone that thinks the bumps are over-modeled in GTR obviously dont have a
> clue about reality. Did you watch the SJ cart race?
>
> I almost cracked a rib when some moron says GTP over models the bumps.


Could've been me. Sorry if I caused you any injury!

A snip from an RAS post of mine on looking at the bump-modeling via Motec:

"if you crank the telemetry data sampling rate up all the way and take a
good look at the suspension travel and damper velocities it appears there's
something funky going on in there. I've seen instances of the suspension
oscillating through a 12cm range (+/-6) in .05-second intervals in fairly
low-speed sections of Spa, and that just looks off to me. Think about it;
up and down 6cm, or 2& 1/4 inches, 20 times per second. That's a jackhammer
on turbo-mode, not a shock absorber."

Don't get me wrong - bump modeling is a good thing. But as I've said
before, I've driven through that section of Spa (Fagnes) back when you could
do it, and have ridden it on a bike with no suspension at all and 21mm tires
at 120psi. It just ain't that bumpy. And BTW, SJ/Champcar is a lousy
comparison; even stiffer cars, and on city streets to boot.

Thank you for playing; please try again... ;-)


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  #62  
Old August 21st 05, 05:30 PM
jason moyer
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Steve Blankenship wrote:

> Don't get me wrong - bump modeling is a good thing.


Bump modelling is a good thing, but the way you feel variations in
pitch and roll in a sim are similar to the way you feel lateral and
longitudinal acceleration. Without the actual physical g-forces acting
on your body, the car will always feel like it's moving more slowly
than it is, that the cornering power is less than it actually is, and
that variations in pitch and roll caused by bumps are less than what
are actually being transferred to the car. Any track that feels
"realistically" bumpy in a sim looks totally ridiculous if you actually
look at the telemetry (and, 99% of the time, in a simple TV cam
replay).

  #63  
Old August 21st 05, 05:42 PM
Saltheart_Foamfollower
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First off I respect your knowledge and experience Steve.

Ive never driven spa and likely never will but I do have eyes and can see
cars of every type bobbing up and down violently when encountering bumps at
speed. All car types and all tracks are effected by bumps although some
are smoother than others (the F1 race in the mid-east comes to mind).

Perhaps the bumps arent modeled perfectly in GTR and the motec data looks
funky but Id rather have a simulation of the bump even if its not perfect
than an unrealistically flat track (which is what weve had to date).

Hmmm. So the Cart race in SJ wasnt an automobile race? Or you just blow it
off because it doesnt fit your questionable argument?

Basically youre saying if they cant do it right dont even try? Where would
we be in simracing had everyone had your idealogy. Nowhere. No Indy500, no
Bill Elliots Nascar Challenge, no Indycar racing 1-2, no F1RC, no GPL, no
NRseries, no GTR, no GTL, no rFactor, no nothing. I prefer the devs at
least try.

Why did GPL get a pass? It has a horrid tire model yet that didnt keep it
from being perhaps the best racing simulation for many years.







"Steve Blankenship" > wrote in message
...
>
>
> Don't get me wrong - bump modeling is a good thing. But as I've said
> before, I've driven through that section of Spa (Fagnes) back when you
> could
> do it, and have ridden it on a bike with no suspension at all and 21mm
> tires
> at 120psi. It just ain't that bumpy. And BTW, SJ/Champcar is a lousy
> comparison; even stiffer cars, and on city streets to boot.
>
> Thank you for playing; please try again... ;-)
>
>



  #64  
Old August 21st 05, 07:20 PM
Steve Blankenship
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"Saltheart_Foamfollower" > wrote in message
...
> First off I respect your knowledge and experience Steve.


Well you didn't wait long to make your 1st mistake... ;-)

> Ive never driven spa and likely never will but I do have eyes and can see
> cars of every type bobbing up and down violently when encountering bumps

at
> speed. All car types and all tracks are effected by bumps although some
> are smoother than others (the F1 race in the mid-east comes to mind).
>
> Perhaps the bumps arent modeled perfectly in GTR and the motec data looks
> funky but Id rather have a simulation of the bump even if its not perfect
> than an unrealistically flat track (which is what weve had to date).


Thus my comment commending bump modeling. I LIKE bumps; glass smooth
surfaces are boring. But dedicated motor racing circuits are by and large
much smoother than the streets we drive on, and the bumps they do have do
not resemble motocross tracks. The damper velocities in Motec look OK, it's
just the range of travel that makes it look off.

> Hmmm. So the Cart race in SJ wasnt an automobile race? Or you just blow

it
> off because it doesnt fit your questionable argument?


Not at all; it's just that the Champcars have stiffer suspensions with less
travel, and city streets, even ones that get some TLC are nowhere near as
smooth as dedicated race tracks, which the GTR tracks are. Those poor
suckers at SJ were getting liquified!

> Basically youre saying if they cant do it right dont even try? Where

would
> we be in simracing had everyone had your idealogy. Nowhere. No Indy500,

no
> Bill Elliots Nascar Challenge, no Indycar racing 1-2, no F1RC, no GPL, no
> NRseries, no GTR, no GTL, no rFactor, no nothing. I prefer the devs at
> least try.


Said nothing of the sort. Only that I think they overshot it going for the
"effect." Hell, I applaud SimBin for doing GTR; I love the idea of it, I
just never could sort out the stuttering graphics or get past the level of
chattering & porpoising. The former was inherited from ISI in gMotor1, but
the latter was their own doing. It may be the bump amplitude in the
surfaces, or some harmonic coming from the frequency of the bumps and the
physics engine. Dunno. I expect the effect on grip, particularly at low
speed, is why ISI is using a two-stage, tweakable cockpit shake effect in
rFactor instead of doing it with the racing surface. Just a guess, though.
Too bad GTR's not as open as native ISI work so you could muck around in
there and see what's what. But I expect they'll have it sorted for the next
iteration of GTR and look forward to that; in the meantime I think I'll be
enjoying GTL.

> Why did GPL get a pass? It has a horrid tire model yet that didnt keep it
> from being perhaps the best racing simulation for many years.


Jeez, man; that was 1998, after all. Papy themselves stealth-tweaked the
tire model with the first patch, and even Kaemmer himself has said the tire
model falls short. Times change. As for it's longevity, GPL was never
perfect; it was just a huge leap over what had come before, and for some
time after it was still the best relative to what else was out there in
terms of the total package. In some ways it arguably still is; thus it's
continued following. I doubt we'll see that big a leap again; what you're
seeing now is convergence, where all sims are beginning to feel more alike.
Which is what you'd expect; cars being cars, after all. But I hope I'm
wrong - I would LOVE to see the sim that would have me uninstalling GPL...


  #65  
Old August 21st 05, 09:27 PM
Dave Henrie
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"Steve Blankenship" > wrote in
:

>
> Could've been me. Sorry if I caused you any injury!
>
> A snip from an RAS post of mine on looking at the bump-modeling via
> Motec:
>
> "if you crank the telemetry data sampling rate up all the way and take
> a good look at the suspension travel and damper velocities it appears
> there's something funky going on in there. I've seen instances of the
> suspension oscillating through a 12cm range (+/-6) in .05-second
> intervals in fairly low-speed sections of Spa, and that just looks off
> to me. Think about it; up and down 6cm, or 2& 1/4 inches, 20 times
> per second. That's a jackhammer on turbo-mode, not a shock absorber."
>


This has nothing to do with this thread,(suprise!) but it might be
interesting none-the-less.

Flipping channels last night I caught a bit of an old Nascar at Bristol
on ESPN Classic. The time frame looked to be around the days of thunder
time.
#3 was there, and Rusty had a black car, M Waltrip was still in the yellow
Kodak Pontiac.

Mark Martin hit the wall. Some time later, they had a pit report and the
showed a shock in two pieces. The bumps were so bad that Martin had pulled
the shock shaft/seal from the shock body. It was not damaged, just pulled
completely out of the shell of the shock absorber. (damper to Euro folk?)

Timely? Yes. Relevant? no. But dang wierd.

dave henrie

  #66  
Old August 21st 05, 11:31 PM
Steve Blankenship
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Default

"Dave Henrie" > wrote in message
. 97.136...
> This has nothing to do with this thread,(suprise!) but it might be
> interesting none-the-less.
>
> Flipping channels last night I caught a bit of an old Nascar at Bristol
> on ESPN Classic. The time frame looked to be around the days of thunder
> time.
> #3 was there, and Rusty had a black car, M Waltrip was still in the

yellow
> Kodak Pontiac.
>
> Mark Martin hit the wall. Some time later, they had a pit report and

the
> showed a shock in two pieces. The bumps were so bad that Martin had

pulled
> the shock shaft/seal from the shock body. It was not damaged, just pulled
> completely out of the shell of the shock absorber. (damper to Euro folk?)
>
> Timely? Yes. Relevant? no. But dang wierd.


Not so weird, Dave. Seen it happen before - the top probably just came
unscrewed from vibration or hadn't been tightened properly. That's how you
rebuild 'em.

Typically not mid-race, though... ;-)


 




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