Re: Driving Sideways: A Discussion

> The front end plows unrealistically, and you have to > oversteer with the throttle to compensate. That forces > us to get unrealistic in another way. This effect COULD be setup related. How about more evenly set arb's? Something like 120/110? Maybe a 45/85 diff? Maybe less positive toe at the rear? I don't know what sort of setup you use but my own personal setups use near equal arb's, -0.175 to -0.250 toe in the front, +0.025 to +0.075 toe in the rear and I use the weight distribution to set the spring rates. I usually run with 100 lb/in at the rear. I find the car to be relatively balanced mid-corner when setup like this and I don't find that it floats excessively. I also use a 45/85-1 differential. -Chris- **Jesus saves sinners and redeems them for valuable cash prizes** Sent via Deja.com http://www.deja.com/ Before you buy.

Interesting. I've not experienced this phenomenon, though I've heard others talk of it. A couple of ideas: -- Could it be related to the linear vs. non-linear settings? I've got my linearity slider set fully linear and have used DXTweak.exe to set my DirectX deadzones to zero. Non-linear steering would not respond to counter-steering nearly as quickly as linear steering at that critical time when you might or might not catch a spin. -- Not enough steering lock? For example: you've got a 20:1 steering ratio so the car behaves well on the straights. If you begin a slide, the slow ratio won't allow much counter-steering so you won't be likely to catch it. Turning OUT of the spin would then completely remove any remaining grip the front end has by putting the fronts at a slip angle so severe the contact patch transitions to fully kinetic contact with no directional control, as opposed to the combined kinetic/static condition and limited control that existed while you were conter- steering. You've then got both ends fully kinetic with no directional control so the only rotation you'll experience is the residial rotational momentum from the initial spin. You won't be increasing your rotational speed by having grip at the front and no grip at the rear. In fact, with both ends fully kinetic, you should have slightly more grip at the rear due to the larger contact patch. I use a 15:1 lock and the only spins I can't catch are the truly GREAT BIG spins where I would likely counter-steer myself off the track if I caught it anyway. -Chris- **Jesus saves sinners and redeems them for valuable cash prizes** > This is my feeling. The self aligning torque (the force that makesthe > tires want to travel straight ahead) is not modeled correctly inGPL. A > tire generally wants to travel in a forward direction since that isthe way > the tread is spinning. In a car, if you lose the grip of the backend in a > corner, not only do the front wheels want to turn to correct the spin(due > to self aligning torque) but the rear wheels are trying their best toline > up with the direction of travel, also. Normally in real life, ifopposite > lock is applied and the car is gradually decelerated (easier to gain > friction back at low speed...but not too abrubt where you transfertoo much > weight forward) the slide will correct and you can continue. Thefirst > thing that annoyed me in GPL (though no game has really gotten itright) is > the fact that once you start to lose the car, if you apply oppositelock > right as it starts to lose it, or a little before it starts to loseit (the > tough part) then you can save it...but if you dont apply it thatsoon, and > apply it a little late, the car spins FASTER. If you are a littleslow on > applying the opposite lock, your best bet is to turn with full lockthe way > the car is spinning. So you are taking a right hand bend and therear end > goes to the left and wants to pass the front...normally you turn leftto > save it, but in GPL, if you turn hard right, the spin will disappearuntil > you can get your speed down and thus regain traction...This is whathas > annoyed me very much since I got GPL. This all goes back to that self > aligning torque and how it is not modeled correctly. So to go backto your > post, I would agree with your #2 idea about tires not modeledcorrectly in

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> GPL making everything a little off. > > JB > > "Chris Cavin" <[email hidden]> wrote in message > news:8s1ps8$699$[email hidden]... > > I would like to figure out how NOT to drive sideways in GPL. > > > > If you view old footage of the 1967 season or footage of vintage

events > > such as the Goodwood Revival, you'll notice that the GPL era cars > > really don't get sideways very often. I won't dispute that theyCOULD > > get very sideways and bring it back, but from the limited footageI've

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> > seen, sideways wasn't the objective but merely an unintended > > consequence. > > > > I have three theories on how this relates to GPL. > > > > One: We drivers in the pseudo world simply drive more aggressively > > than the real drivers of these cars. Obviously we have nothing to

fear > > from the reaper if we end decorating the trees lining Eau Rouge, sowhy > > NOT attempt every corner at one hundred and five percent? I think, > > however, it's possible that the real 1967 cars could have beendriven a > > bit more sideways, but realism and the desire not to be a treeornament > > dictated that they weren't. > > > > Two: Tire modeling. Every tire demonstrates a certain slip angleat > > its maximum lateral grip. This slip angle has been decreased overthe > > years to the point that it's now so small as to be nearlyunnoticeable > > to outside observers. Certainly the optimum slip angle was largerin > > 1967. Look at Dan Gurney's Eagle in the Zandvoort picture (fifth > > picture down from the top) at > > http://www.allamericanracers.com/gurney_grand-prix/eagle_f1-photo.html > > and you'll notice that the rear tires don't follow exactly in thepath > > of the fronts. The large (by today's standards) slip angle makesthe > > rear end take a "set" about a third or a half of a tire widthtowards > > the outside of the corner. Now, look at a replay of yourself fromTV1 > > or TV2 when negotiating a corner in GPL. Ascari at Monza would be > > ideal for this. Notice how much farther your back end "sets" itself > > towards the outside of the corner. I'm lead to believe by this that > > the tire model in GPL uses an exaggerated amount of slip angle. Ifthe > > slip angle in the picture of Dan Gurney is, for example, fivedegrees, > > I would place the slip angle in GPL closer to 15 degrees. Add tothat > > the 15 or 20 degrees of angle that occur when sliding and you getsome > > of the more outrageous driving styles we see in GPL. > > > > Three: This theory is sort of a conglomeration of theories one and > > two. I remember reading somewhere that Papy took away grip fromGPL as > > a concession to game play. I think it's possible that theexaggerated > > slip angles of theory two are deliberately included as a result of > > theory one. If realistic tire grip and slip angles were modeledinto > > the game, we'd all be running 7:15 laps at the 'Ring and 0:58 lapsat > > the Glen because of theory number one. > > > > Now that I've said all this I don't intend it to be a criticism ofPapy > > or of GPL. I simply offer these ideas up for discussion. Heck, I'm > > bored and we haven't had this debate for a while anyway. Maybe wecan > > even come up with some setup solutions that will keep the tail morein

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> > line in the future. > > > > -Chris- > > > > **Jesus saves sinners and redeems them for valuable cash prizes** > > > > > > Sent via Deja.com http://www.deja.com/ > > Before you buy. > >

-- Sent via Deja.com http://www.deja.com/ Before you buy.

>This is my feeling. The self aligning torque (the force that makes the >tires want to travel straight ahead) is not modeled correctly in GPL. A >tire generally wants to travel in a forward direction since that is the way >the tread is spinning. I disagree. I started writing a vehicle dynamics model a few months ago and had a problem with the car refusing to straighten out. Someone asked if perhaps I had neglected to do the self aligning torque at the tires. After putting in the effect, I was surprised to see that these self-aligning torques the tires produce cancel each other out almost perfectly, and had next to *zero* effect on the handling of the car. The problem turned out to be in the way I was limiting sideforce at the tires. >In a car, if you lose the grip of the back end in a >corner, not only do the front wheels want to turn to correct the spin (due >to self aligning torque) but the rear wheels are trying their best to line >up with the direction of travel, also. What you could do (if you wanted) is draw a little car on paper from a top down view. Put the center of gravity in the middle, and draw a line pointing from the center of gravity to a 90 degree angle from each tire. If the self aligning torques are all twisting the tires in the same direction, you end up with four nearly identical forces pointing at about 90 degree intervals to each other at the center of gravity. There IS an effect in some situations, but it's so tiny it's not worth bothering with, in my opinion. The self aligning torque calculations' main benefit are they enable you to calculate what the torque at the *steering wheel* is, so you can take the slip angles at the front tires (with load, camber, or whatever else you deal with in your tire model), and generate a torque to power the forcefeedback wheel with. GPL has force feedback, and folks have said it's pretty good, so I imagine they do the self aligning correctly. > The first >thing that annoyed me in GPL (though no game has really gotten it right) is >the fact that once you start to lose the car, if you apply opposite lock >right as it starts to lose it, or a little before it starts to lose it (the >tough part) then you can save it...but if you dont apply it that soon, and >apply it a little late, the car spins FASTER. One thing to possibly look at here is what's happening to the slip angles at the front tires vs. the rear. It's hard to explain, but imagine snapping the wheel to the right while driving a straight line. The front tires may be at 10 degrees of slip (this is the peak of the force curve in this example). The car begins to rotate. First, it rotates one degree. Now the rears are at 1 degree of slip (which fights against the front end, trying to straighten out the car, forget about self aligning torque), and the fronts are at 11. Since the fronts are at 11, they don't generate as much force as they would if they were at 10 degrees. In essence, if you unwound the steering wheel (opposite locked) just quickly enough to keep the fronts at 10 degrees of slip while the rear end was coming around, you'd spin the car much more quickly then you would if you'd have kept the steering wheel in the original spot and let the slip angles climb past 10 (where there isn't quite as much sideforce, and the direction of the force depletes the turning torque on the C.G. even more). >f you are a little slow on >applying the opposite lock, your best bet is to turn with full lock the way >the car is spinning. So you are taking a right hand bend and the rear end >goes to the left and wants to pass the front...normally you turn left to >save it, but in GPL, if you turn hard right, the spin will disappear until >you can get your speed down and thus regain traction.. Exactly correct. By turning the fronts INTO the turn even further, you deplete the sideforce at the front end, the same way you would if you turned the wheel *less*. Remember, anything beyond 10 degrees or so of slip angle produces LESS sideforce (actually, we should be talking torque around the center of gravity of the car, in which case the direction of this force depletes it further.) >This is what has >annoyed me very much since I got GPL. Hmmm.... ;-) There was a post a few weeks ago by a gentleman who races Solo II events. He described this phenomenon as being a surprise when he discovered it during a real event. He was amazed to discover that once he'd set the steering wheel angle to a certain point, turning it less OR turning it more caused his Solo II car to tend to straighten itself out (understeer). Try it out in an abandoned parking lot sometime, it's true :-) >This all goes back to that self >aligning torque and how it is not modeled correctly. Nope. Nothing to do with self aligning torque. That's just for force feedback :-) >So to go back to your >post, I would agree with your #2 idea about tires not modeled correctly in >GPL making everything a little off. I didn't read the #2 idea, but what I believe is happening in GPL with "excessive sliding" is nothing more than a slight cornering stiffness exaggeration. The GPL tire may pull 1g at 10 degrees of slip angle, while the real tire may pull 1g at only 5 degrees of slip. The result is you get a car that doesn't feel as "tight" as the real thing, but has the same *total* amount of grip as the real car. In other words, you'd go around a skidpad in the same amount of time as the real car, but the "sliding or slip" angle would be a little bigger, kind of like you'd let some air out of the tires. "Cornering stiffness" is the problem, not "lack of grip". Sorry if this reply sounds like a flame, JB, I mean no offense, I just wanted to input my current understanding. Todd Wasson --- Performance Simulations Drag Racing and Top Speed Prediction Software http://PerformanceSimulations.Com

I would like to figure out how NOT to drive sideways in GPL. If you view old footage of the 1967 season or footage of vintage events such as the Goodwood Revival, you'll notice that the GPL era cars really don't get sideways very often. I won't dispute that they COULD get very sideways and bring it back, but from the limited footage I've seen, sideways wasn't the objective but merely an unintended consequence. I have three theories on how this relates to GPL. One: We drivers in the pseudo world simply drive more aggressively than the real drivers of these cars. Obviously we have nothing to fear from the reaper if we end decorating the trees lining Eau Rouge, so why NOT attempt every corner at one hundred and five percent? I think, however, it's possible that the real 1967 cars could have been driven a bit more sideways, but realism and the desire not to be a tree ornament dictated that they weren't. Two: Tire modeling. Every tire demonstrates a certain slip angle at its maximum lateral grip. This slip angle has been decreased over the years to the point that it's now so small as to be nearly unnoticeable to outside observers. Certainly the optimum slip angle was larger in 1967. Look at Dan Gurney's Eagle in the Zandvoort picture (fifth picture down from the top) at http://www.allamericanracers.com/gurney_grand-prix/eagle_f1-photo.html and you'll notice that the rear tires don't follow exactly in the path of the fronts. The large (by today's standards) slip angle makes the rear end take a "set" about a third or a half of a tire width towards the outside of the corner. Now, look at a replay of yourself from TV1 or TV2 when negotiating a corner in GPL. Ascari at Monza would be ideal for this. Notice how much farther your back end "sets" itself towards the outside of the corner. I'm lead to believe by this that the tire model in GPL uses an exaggerated amount of slip angle. If the slip angle in the picture of Dan Gurney is, for example, five degrees, I would place the slip angle in GPL closer to 15 degrees. Add to that the 15 or 20 degrees of angle that occur when sliding and you get some of the more outrageous driving styles we see in GPL. Three: This theory is sort of a conglomeration of theories one and two. I remember reading somewhere that Papy took away grip from GPL as a concession to game play. I think it's possible that the exaggerated slip angles of theory two are deliberately included as a result of theory one. If realistic tire grip and slip angles were modeled into the game, we'd all be running 7:15 laps at the 'Ring and 0:58 laps at the Glen because of theory number one. Now that I've said all this I don't intend it to be a criticism of Papy or of GPL. I simply offer these ideas up for discussion. Heck, I'm bored and we haven't had this debate for a while anyway. Maybe we can even come up with some setup solutions that will keep the tail more in line in the future. -Chris- **Jesus saves sinners and redeems them for valuable cash prizes** Sent via Deja.com http://www.deja.com/ Before you buy.

> I remember reading a transcript of an interview with David Kaemmer > at a recent game show [SNIP] You wouldn't happen to have a link to the transcript, would you? -Chris- **Jesus saves sinners and redeems them for valuable cash prizes** Sent via Deja.com http://www.deja.com/ Before you buy.

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> > Now that I've said all this I don't intend it to be a criticism > > of Papy or of GPL. > > Why not? Haven't we done enough ass-kissing already? :) > > I remember reading a transcript of an interview with David Kaemmer > at a recent game show, and he bluntly stated that they overdid the > sliding in GPL, although he thought it's reasonably close. So there > you go. I've never seen so much sliding on any footage that I've > seen, either, but it's not something I lose sleep over, and frankly, > it's kind of fun to do.

I agree with you there. There's no other game I'm interested in that I find more fun or, more importantly, that I find more satisfying. After two years of playing I *STILL* can't drive the perfect lap (MY perfect lap, not THE perfect lap) more than once in a blue moon. But when I do, hooooooo boy! I read an interview with the Kenny Roberts, Jr. in which he was asked about the skills required to ride a 500cc Grand Prix machine. He quoted fellow rider Valentino Rossi who had recently ridden a World Superbike machine at the Suzuka 8 Hours and who also rides a 500cc Grand Prix Honda. Words to the effect that "you can ride a WSB to 100% of it's limits for each and every lap you're on the track the whole year. You might ride a 500cc GP bike to it's limits, however, only four times a season." I feel a bit that way towards GPL. I can very rarely get the best out of the car and myself all at once. But I know it's there for the finding and I truly enjoy that process. I doubt I'll ever tire of GPL and I can see myself keeping a machine around for years to run GPL exclusively if the hardware ever renders it obsolete. -Chris- **Jesus saves sinners and redeems them for valuable cash prizes** Sent via Deja.com http://www.deja.com/ Before you buy.

> Now that I've said all this I don't intend it to be a criticism of Papy > or of GPL. Why not? Haven't we done enough ass-kissing already? :) I remember reading a transcript of an interview with David Kaemmer at a recent game show, and he bluntly stated that they overdid the sliding in GPL, although he thought it's reasonably close. So there you go. I've never seen so much sliding on any footage that I've seen, either, but it's not something I lose sleep over, and frankly, it's kind of fun to do.

On Wed, 11 Oct 2000 15:21:55 GMT, Chris Cavin <[email hidden]> wrote:

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> >> I remember reading a transcript of an interview with David Kaemmer >> at a recent game show > >[SNIP] > >You wouldn't happen to have a link to the transcript, would you?

Read the whole interview here: http://www.simracingnews.com/newscenter/e3/articles/davekaemmer/index.shtml His words: "It might have been a little exaggerated. But I don't think that it's too far off." Andre

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> >-Chris- > >**Jesus saves sinners and redeems them for valuable cash prizes** > > >Sent via Deja.com http://www.deja.com/ >Before you buy.

I've put a lot of thought into this lately as well, but I'm not so sure about laptimes being considerably lower than they are now. I don't think the folks at Papy counted on setup theory evolving in such a way as to take advantage of the slip angle rather than work around it. If the slip angles were smaller (i.e. more grip) I think that cars setup with the diff. settings such as 85/xx 3 or 4 clutches would give so much understeer as to be unusable (tires would overheat pretty quickly I would guess). The more conventional real world 45/xx ramp angles would still be difficult to get used to, since the car will break away fairly quickly in fact probably with less warning if the slip angle is narrower, but you wouldn't have as short a brake distance that a diff packed with clutches will provide. Maybe... Check this out...snipped it from an article someone posted a link to on vroc-f2 mailing list...if you'd like to read the full article check here http://www.telegraph.co.uk/et?ac=003537760806415&rtmo=Ll3LdxLd&atmo=Ll3LdxLd&pg=/et/99/9/21/emflotu21.html Hmm....kinda long prolly need to snip and paste Boot it in second. The nose runs wide on the dusty track, so back off a little, then boot it again as you feel the grip come back. Hear the revs rise as the rear wheels start to spin, kick the tail to the left. A flick of the big, leather-rimmed wheel holds it, but you have to keep the faith, keep some power on. Not so much that the car gets looser, but enough to let the slide straighten itself out. Wimp out and the tail snaps back, makes you turn right again, looks messy. Jochen Rindt or Graham Hill wouldn't have done that. Back up the other side of the loop, all the way to fifth, flash past the rows of onlookers who have streamed from the Lotus offices - "It costs the factory a lot every time we do this" - then all the way down to second for the right-hander. There's more grip here and the nose bites, letting the tail gently swing round with barely any lock. Then it's immediately left again, but now the nose doesn't want to help. More lock, then back off as you ease on the power, wait for the tail to slip, catch it, then feel it dig in and catapult the car to the second hairpin. Brake hard, feel the tyres scrabble and the engine shimmy as you gently lever from third across the gate for first. Wait again for what seems like for ever for the corner to unfold, then carefully tread the pedal to the floor. A crescendo of revs and a slithering tail. Immediately throw the lever forward for second and let the car straighten itself as you head off down the runway for another glorious sliding, shimmying experience. I couldn't believe how much it moved about. Whenever the 49 was in a corner, I was working; it must have been a treat to see the greats managing the energy, getting the slides to work for them without wasting any speed.

I believe I read a David Kaemmer interview, where he was talking about taking a race school, and driving a race car for the first time, AFTER, gpl was on the market. He was pleasantly surprised that some of the things he was feeling he had already experienced in gpl. It is unfortunate that he hadn't taken the race school before releasing gpl, if so, the suggestions of beta tester Doug Arnao might have been implimented, and the gpl driving experience would have been much better IMHO. GPL cars have to much mass for the level of traction, so it's more like driving on snow than pavement. The front end plows unrealistically, and you have to oversteer with the throttle to compensate. That forces us to get unrealistic in another way. Searching for traction, setups get super soft, so my 1200lb F1 car floats around on it's suspension way more than my real life 2400lb VW GTI road car, making them even harder to control, and more unrealistic in feel. I personally wouldn't care if the lap times in gpl didn't match the real life 67 times. I would much rather up the traction and bring the driving feel closer to reality. -- Don Scurlock Vancouver,B.C. GPLRank -5.09 Come see how you rank, at the GPLRank site http://gplrank.ringlord.com/

This is my feeling. The self aligning torque (the force that makes the tires want to travel straight ahead) is not modeled correctly in GPL. A tire generally wants to travel in a forward direction since that is the way the tread is spinning. In a car, if you lose the grip of the back end in a corner, not only do the front wheels want to turn to correct the spin (due to self aligning torque) but the rear wheels are trying their best to line up with the direction of travel, also. Normally in real life, if opposite lock is applied and the car is gradually decelerated (easier to gain friction back at low speed...but not too abrubt where you transfer too much weight forward) the slide will correct and you can continue. The first thing that annoyed me in GPL (though no game has really gotten it right) is the fact that once you start to lose the car, if you apply opposite lock right as it starts to lose it, or a little before it starts to lose it (the tough part) then you can save it...but if you dont apply it that soon, and apply it a little late, the car spins FASTER. If you are a little slow on applying the opposite lock, your best bet is to turn with full lock the way the car is spinning. So you are taking a right hand bend and the rear end goes to the left and wants to pass the front...normally you turn left to save it, but in GPL, if you turn hard right, the spin will disappear until you can get your speed down and thus regain traction...This is what has annoyed me very much since I got GPL. This all goes back to that self aligning torque and how it is not modeled correctly. So to go back to your post, I would agree with your #2 idea about tires not modeled correctly in GPL making everything a little off. JB "Chris Cavin" <[email hidden]> wrote in message news:8s1ps8$699$[email hidden]...

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> I would like to figure out how NOT to drive sideways in GPL. > > If you view old footage of the 1967 season or footage of vintage events > such as the Goodwood Revival, you'll notice that the GPL era cars > really don't get sideways very often. I won't dispute that they COULD > get very sideways and bring it back, but from the limited footage I've > seen, sideways wasn't the objective but merely an unintended > consequence. > > I have three theories on how this relates to GPL. > > One: We drivers in the pseudo world simply drive more aggressively > than the real drivers of these cars. Obviously we have nothing to fear > from the reaper if we end decorating the trees lining Eau Rouge, so why > NOT attempt every corner at one hundred and five percent? I think, > however, it's possible that the real 1967 cars could have been driven a > bit more sideways, but realism and the desire not to be a tree ornament > dictated that they weren't. > > Two: Tire modeling. Every tire demonstrates a certain slip angle at > its maximum lateral grip. This slip angle has been decreased over the > years to the point that it's now so small as to be nearly unnoticeable > to outside observers. Certainly the optimum slip angle was larger in > 1967. Look at Dan Gurney's Eagle in the Zandvoort picture (fifth > picture down from the top) at > http://www.allamericanracers.com/gurney_grand-prix/eagle_f1-photo.html > and you'll notice that the rear tires don't follow exactly in the path > of the fronts. The large (by today's standards) slip angle makes the > rear end take a "set" about a third or a half of a tire width towards > the outside of the corner. Now, look at a replay of yourself from TV1 > or TV2 when negotiating a corner in GPL. Ascari at Monza would be > ideal for this. Notice how much farther your back end "sets" itself > towards the outside of the corner. I'm lead to believe by this that > the tire model in GPL uses an exaggerated amount of slip angle. If the > slip angle in the picture of Dan Gurney is, for example, five degrees, > I would place the slip angle in GPL closer to 15 degrees. Add to that > the 15 or 20 degrees of angle that occur when sliding and you get some > of the more outrageous driving styles we see in GPL. > > Three: This theory is sort of a conglomeration of theories one and > two. I remember reading somewhere that Papy took away grip from GPL as > a concession to game play. I think it's possible that the exaggerated > slip angles of theory two are deliberately included as a result of > theory one. If realistic tire grip and slip angles were modeled into > the game, we'd all be running 7:15 laps at the 'Ring and 0:58 laps at > the Glen because of theory number one. > > Now that I've said all this I don't intend it to be a criticism of Papy > or of GPL. I simply offer these ideas up for discussion. Heck, I'm > bored and we haven't had this debate for a while anyway. Maybe we can > even come up with some setup solutions that will keep the tail more in > line in the future. > > -Chris- > > **Jesus saves sinners and redeems them for valuable cash prizes** > > > Sent via Deja.com http://www.deja.com/ > Before you buy.

rrevved <[email hidden]> wrote in message news:[email hidden]...

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> > was a too difficult because the team wouldn't compromise. When you > mastered it [GPL], you felt you really had acomplished > something......problem was if you walked away from it for any length > of time, you had to put, IMHO, too much work to return to that form. > This eventually kept me from returning to it. Maybe I'm just getting > too old? <g> >

And that's what I love and hate about GPL. When working on my PhD, I had lots of late night "dead time" waiting for experiments or simulation runs to finish. Sleeping didn't seem like the most interesting thing to do, so I put some time into GPL and managed to get pretty good at it. Not in the leagues of the "stars" here, but up to winning AI races. Now that the PhD is done, my free-time is more limited (much to my chagrin) and I find it frustrating to come back to GPL and be back to drifting wide, spinning on corner entries, clipping wheels etc. In the end, I gave up and GPL disappeared from the HD. Much as I can appreciate the accuracy of the simulation, I can't justify the time it requires to maintain those skills. I find myself now gravitating towards "sims" which have plausible (not necessarily 100% accurate) car modelling, but which also allow one to drop back in after a break and still have fun right away. NFS:Porsche online and GP3 offline fill the bill for me, but I will admit there is always that nagging little voice in my head saying "man, if only they had modelled this or that..." Waiting to see what comes out of the West Brothers shop, as Nascar doesn't fire me up much. Stephen

Well, apparently I'm in the minority here, but I never got the impression that the very best GPL drivers get sideways much. I used to have a Wolfgang Woeger replay where he got waaay sideways coming off that last corner of the Nurburgring before he started his lap, but he was only showing off, or having some fun. Once his actual hotlap started, he kept it very tight all the way around the track. I always do my best laps when I drive agressively, but don't quite get so out of shape that I need to apply opposite lock, and from watching Greger, and some other fast guys, that seems to be what they aim for too. I believe that it's okay to slide a bit, but when you need to apply opposite lock, or even worse, turn into a slide, then you're actually a bit over the limit. Loud tire squeal, and a tiny bit of four-wheel-drift is my goal. But it could be you've seen some hotlap replays that I haven't seen yet. I don't spend much time watching them. :) -A "Chris Cavin" <[email hidden]> wrote in message news:8s1ps8$699$[email hidden]...

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> I would like to figure out how NOT to drive sideways in GPL. > > If you view old footage of the 1967 season or footage of vintage events > such as the Goodwood Revival, you'll notice that the GPL era cars > really don't get sideways very often. I won't dispute that they COULD > get very sideways and bring it back, but from the limited footage I've > seen, sideways wasn't the objective but merely an unintended > consequence. > > I have three theories on how this relates to GPL. > > One: We drivers in the pseudo world simply drive more aggressively > than the real drivers of these cars. Obviously we have nothing to fear > from the reaper if we end decorating the trees lining Eau Rouge, so why > NOT attempt every corner at one hundred and five percent? I think, > however, it's possible that the real 1967 cars could have been driven a > bit more sideways, but realism and the desire not to be a tree ornament > dictated that they weren't. > > Two: Tire modeling. Every tire demonstrates a certain slip angle at > its maximum lateral grip. This slip angle has been decreased over the > years to the point that it's now so small as to be nearly unnoticeable > to outside observers. Certainly the optimum slip angle was larger in > 1967. Look at Dan Gurney's Eagle in the Zandvoort picture (fifth > picture down from the top) at > http://www.allamericanracers.com/gurney_grand-prix/eagle_f1-photo.html > and you'll notice that the rear tires don't follow exactly in the path > of the fronts. The large (by today's standards) slip angle makes the > rear end take a "set" about a third or a half of a tire width towards > the outside of the corner. Now, look at a replay of yourself from TV1 > or TV2 when negotiating a corner in GPL. Ascari at Monza would be > ideal for this. Notice how much farther your back end "sets" itself > towards the outside of the corner. I'm lead to believe by this that > the tire model in GPL uses an exaggerated amount of slip angle. If the > slip angle in the picture of Dan Gurney is, for example, five degrees, > I would place the slip angle in GPL closer to 15 degrees. Add to that > the 15 or 20 degrees of angle that occur when sliding and you get some > of the more outrageous driving styles we see in GPL. > > Three: This theory is sort of a conglomeration of theories one and > two. I remember reading somewhere that Papy took away grip from GPL as > a concession to game play. I think it's possible that the exaggerated > slip angles of theory two are deliberately included as a result of > theory one. If realistic tire grip and slip angles were modeled into > the game, we'd all be running 7:15 laps at the 'Ring and 0:58 laps at > the Glen because of theory number one. > > Now that I've said all this I don't intend it to be a criticism of Papy > or of GPL. I simply offer these ideas up for discussion. Heck, I'm > bored and we haven't had this debate for a while anyway. Maybe we can > even come up with some setup solutions that will keep the tail more in > line in the future. > > -Chris- > > **Jesus saves sinners and redeems them for valuable cash prizes** > > > Sent via Deja.com http://www.deja.com/ > Before you buy.

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> Well, apparently I'm in the minority here, but I never got the > impression that the very best GPL drivers get sideways much. > I used to have a Wolfgang Woeger replay where he got waaay > sideways coming off that last corner of the Nurburgring before > he started his lap, but he was only showing off, or having some > fun. Once his actual hotlap started, he kept it very tight all > the way around the track. > > I always do my best laps when I drive agressively, but don't > quite get so out of shape that I need to apply opposite lock, > and from watching Greger, and some other fast guys, that seems > to be what they aim for too. I believe that it's okay to slide > a bit, but when you need to apply opposite lock, or even worse, > turn into a slide, then you're actually a bit over the limit. > Loud tire squeal, and a tiny bit of four-wheel-drift is my goal. > > But it could be you've seen some hotlap replays that I haven't > seen yet. I don't spend much time watching them. :) > > -A

I don't disagree with you at all. My previous point was referring to the tail out "set" that the cars in GPL take as a normal occurence BEFORE you need to apply any opposite lock. Not the wild power sliding type of driving some have demonstrated. -Chris- **Jesus saves sinners and redeems them for valuable cash prizes** Sent via Deja.com http://www.deja.com/ Before you buy.

J. Todd Wasson <[email hidden]> wrote in message news:[email hidden]... > >This is my feeling. The self aligning torque (the force that makes the > >tires want to travel straight ahead) is not modeled correctly in GPL. A > >tire generally wants to travel in a forward direction since that is theway > >the tread is spinning. > > I disagree. I started writing a vehicle dynamics model a few months agoand > had a problem with the car refusing to straighten out. Someone asked if > perhaps I had neglected to do the self aligning torque at the tires.After > putting in the effect, I was surprised to see that these self-aligningtorques > the tires produce cancel each other out almost perfectly, and had next to > *zero* effect on the handling of the car. The problem turned out to be inthe > way I was limiting sideforce at the tires. > > > >In a car, if you lose the grip of the back end in a > >corner, not only do the front wheels want to turn to correct the spin(due > >to self aligning torque) but the rear wheels are trying their best toline > >up with the direction of travel, also. > > What you could do (if you wanted) is draw a little car on paper from atop > down view. Put the center of gravity in the middle, and draw a linepointing > from the center of gravity to a 90 degree angle from each tire. If theself > aligning torques are all twisting the tires in the same direction, you endup > with four nearly identical forces pointing at about 90 degree intervals toeach > other at the center of gravity. There IS an effect in some situations,but > it's so tiny it's not worth bothering with, in my opinion. > > The self aligning torque calculations' main benefit are they enable youto > calculate what the torque at the *steering wheel* is, so you can take theslip > angles at the front tires (with load, camber, or whatever else you dealwith in > your tire model), and generate a torque to power the forcefeedback wheelwith. > GPL has force feedback, and folks have said it's pretty good, so I imaginethey > do the self aligning correctly. It sure does. When I accelerated out of a tight corner, I pretty much relax my arms and test the throttle and try to keep it in the range of slight wheelspin, so I can feel my limit. Works well. > > > > The first > >thing that annoyed me in GPL (though no game has really gotten it right)is > >the fact that once you start to lose the car, if you apply opposite lock > >right as it starts to lose it, or a little before it starts to lose it(the > >tough part) then you can save it...but if you dont apply it that soon,and > >apply it a little late, the car spins FASTER. > > > One thing to possibly look at here is what's happening to the slipangles at > the front tires vs. the rear. It's hard to explain, but imagine snappingthe > wheel to the right while driving a straight line. The front tires may beat 10 > degrees of slip (this is the peak of the force curve in this example).The car > begins to rotate. First, it rotates one degree. Now the rears are at 1degree > of slip (which fights against the front end, trying to straighten out thecar, > forget about self aligning torque), and the fronts are at 11. Since thefronts > are at 11, they don't generate as much force as they would if they were at10 > degrees. In essence, if you unwound the steering wheel (opposite locked)just > quickly enough to keep the fronts at 10 degrees of slip while the rear endwas > coming around, you'd spin the car much more quickly then you would ifyou'd > have kept the steering wheel in the original spot and let the slip anglesclimb > past 10 (where there isn't quite as much sideforce, and the direction ofthe > force depletes the turning torque on the C.G. even more). > > > >f you are a little slow on > >applying the opposite lock, your best bet is to turn with full lock theway > >the car is spinning. So you are taking a right hand bend and the rearend > >goes to the left and wants to pass the front...normally you turn left to > >save it, but in GPL, if you turn hard right, the spin will disappearuntil > >you can get your speed down and thus regain traction.. > > Exactly correct. By turning the fronts INTO the turn even further, you > deplete the sideforce at the front end, the same way you would if youturned > the wheel *less*. Remember, anything beyond 10 degrees or so of slipangle

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> produces LESS sideforce (actually, we should be talking torque around the > center of gravity of the car, in which case the direction of this force > depletes it further.) > > > >This is what has > >annoyed me very much since I got GPL. > > Hmmm.... ;-) There was a post a few weeks ago by a gentleman who races

Solo > II events. He described this phenomenon as being a surprise when hediscovered > it during a real event. He was amazed to discover that once he'd set the > steering wheel angle to a certain point, turning it less OR turning itmore > caused his Solo II car to tend to straighten itself out (understeer). Tryit

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> out in an abandoned parking lot sometime, it's true :-) > > > >This all goes back to that self > >aligning torque and how it is not modeled correctly. > > Nope. Nothing to do with self aligning torque. That's just for force > feedback :-) > > >So to go back to your > >post, I would agree with your #2 idea about tires not modeled correctly

in > >GPL making everything a little off. > > I didn't read the #2 idea, but what I believe is happening in GPL with > "excessive sliding" is nothing more than a slight cornering stiffness > exaggeration. The GPL tire may pull 1g at 10 degrees of slip angle, whilethe > real tire may pull 1g at only 5 degrees of slip. The result is you get acar > that doesn't feel as "tight" as the real thing, but has the same *total*amount > of grip as the real car. In other words, you'd go around a skidpad in thesame > amount of time as the real car, but the "sliding or slip" angle would be a > little bigger, kind of like you'd let some air out of the tires."Cornering > stiffness" is the problem, not "lack of grip". > > Sorry if this reply sounds like a flame, JB, I mean no offense, I justwanted

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> to input my current understanding. > > > Todd Wasson > --- > Performance Simulations > Drag Racing and Top Speed Prediction > Software > http://PerformanceSimulations.Com

"Chris Cavin" <[email hidden]> wrote in message news:8s3154$9i5$[email hidden]... > I don't disagree with you at all. My previous point was referring to > the tail out "set" that the cars in GPL take as a normal occurence > BEFORE you need to apply any opposite lock. Not the wild power sliding > type of driving some have demonstrated. > Okay, I see what you're saying. You're being literal when you say "sideways". Usually when people talk about "getting sideways" they mean "hanging the rear end out", so that threw me off. You might be right about the slip-angles, but I'd like to point out that you really can't tell anything from photos. In that Gurney photo, for example, you have no way to know precisely what direction the car is moving. He's not neccessarily following the racing groove. He could be coming straight at us for all we know. -A

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> > I don't disagree with you at all. My previous point was referring > > to the tail out "set" that the cars in GPL take as a normal > > occurence BEFORE you need to apply any opposite lock. Not the > >wild power sliding type of driving some have demonstrated. > > > > Okay, I see what you're saying. You're being literal when you say > "sideways". Usually when people talk about "getting sideways" they > mean "hanging the rear end out", so that threw me off. > > You might be right about the slip-angles, but I'd like to point > out that you really can't tell anything from photos. In that > Gurney photo, for example, you have no way to know precisely > what direction the car is moving. He's not neccessarily > following the racing groove. He could be coming straight > at us for all we know. > > -A

This is true. I haven't found a really good picture to demonstrate this, though. Probably can't. Video does a much better job. My main frame of reference is the Jim Clark tribute video that is going around now and some of the vintage racing I've seen on TV from the Goodwood Revival last year. Nobody was particularly "hanging it out" from what I saw. A little power slide here and there, but nothing drastic. -Chris- **Jesus saves sinners and redeems them for valuable cash prizes** Sent via Deja.com http://www.deja.com/ Before you buy.

In article <Nr7F5.2241 $[email hidden]>, "Aubrey" <[email hidden]> wrote: > Well, apparently I'm in the minority here, butI never got the impression > that the very best GPL drivers get sidewaysmuch. I used to have a Wolfgang > Woeger replay where he got waaay sidewayscoming off that last corner of the > Nurburgring before he started his lap, but hewas only showing off, or > having some fun hi Aubrey If you still have the replay - would you please send it to me? I need it for a Mpeg. thanks Wolfgang Sent via Deja.com http://www.deja.com/ Before you buy.

I used to have a Wolfgang > Woeger replay where he got waaay sidewayscoming off that last corner of the > Nurburgring before he started his lap, but hewas only showing off, or > having some fun. Once his actual hotlapstarted, he kept it very tight all > the way around the track. hi Aubrey If you still have the replay .... would you be so kind and send it to me? I need it for a mpeg but lost it. thanks Wolfgang Sent via Deja.com http://www.deja.com/ Before you buy.

hehehe:-) thanks anyway and cya Wolfgang In article <5rNH5.1008 $[email hidden]>, "Aubrey" <[email hidden]> wrote: > Nope, sorry Wolfgang, I've done some"housecleaning" since then. Can't you

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> just make another one? ;o) > > Hope you find it. It was cool. > > <[email hidden]> wrote in message > news:8sn62d$5n8$[email hidden]... > > I used to have a Wolfgang > > > Woeger replay where he got waaay sideways > > coming off that last corner of the > > > Nurburgring before he started his lap, but

he

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> > was only showing off, or > > > having some fun. Once his actual hotlap > > started, he kept it very tight all > > > the way around the track. > > > > > > hi Aubrey > > > > If you still have the replay .... would you

be so > > kind and send it to me? I need it for a mpegbut

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> > lost it. > > > > thanks > > > > Wolfgang > > > > > > Sent via Deja.com http://www.deja.com/ > > Before you buy. > > > >

Sent via Deja.com http://www.deja.com/ Before you buy.

Nope, sorry Wolfgang, I've done some "housecleaning" since then. Can't you just make another one? ;o) Hope you find it. It was cool. <[email hidden]> wrote in message news:8sn62d$5n8$[email hidden]...

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> I used to have a Wolfgang > > Woeger replay where he got waaay sideways > coming off that last corner of the > > Nurburgring before he started his lap, but he > was only showing off, or > > having some fun. Once his actual hotlap > started, he kept it very tight all > > the way around the track. > > > hi Aubrey > > If you still have the replay .... would you be so > kind and send it to me? I need it for a mpeg but > lost it. > > thanks > > Wolfgang > > > Sent via Deja.com http://www.deja.com/ > Before you buy. >

Chris Cavin wrote: Aubrey wrote:

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>> You might be right about the slip-angles, but I'd like to point >> out that you really can't tell anything from photos. In that >> Gurney photo, for example, you have no way to know precisely >> what direction the car is moving. He's not neccessarily >> following the racing groove. He could be coming straight >> at us for all we know. >> -A > >This is true. I haven't found a really good picture to demonstrate >this, though. Probably can't. Video does a much better job. My main >frame of reference is the Jim Clark tribute video that is going around >now and some of the vintage racing I've seen on TV from the Goodwood >Revival last year. Nobody was particularly "hanging it out" from what >I saw. A little power slide here and there, but nothing drastic. > >-Chris-

There is a fabulous photo of Jack Brabham at Paul Henri Cahier's site. Sir Jack has the car in a huge drift, with just a touch of opposite lock, at Zandvoort in '66. Start at http://www.f1-photo.com/, go to the Photo Gallery and the "BC" section in the 50-60s. After that be sure to browse through all of Cahier's modern photography. He's brilliant. -Ferdinand-