N4 steering and slides

You guys noticed that when your driving that if you steer harder into the wrong direction when the rear kicks out that you can save it? Say the rear kicks right, if you steer harder to the left you can save the car as oppose4d to steering into the spin......that cant possibly be correct could it??????????????

That is actually what the real Nascar drivers do somtimes. If you can't catch it going hard opposite lock, go full lock and the front end will break traction as the wheels are almost perpendicular to the road direction. It will seem wierd at first, but it works and is used in GPL a lot, when the slide is 'unrecoverable'. Kinda, almost, a 'cheat'. Ooops! did I say the 'C' word?? :)))) James "Ronnie Bigwhip" <[email hidden]> wrote in message news:utiMuDWbAHA.270@cpmsnbbsa09... You guys noticed that when your driving that if you steer harder into the wrong direction when the rear kicks out that you can save it? Say the rear kicks right, if you steer harder to the left you can save the car as oppose4d to steering into the spin......that cant possibly be correct could it??????????????

Until you show me some real proof of this, James. I won't believe you. ;) Any mpgs or pics out there where is shows a driver turning in full lock(Not opposite lock) to save a spin? If the spin was too far gone I could see a Cup driver puting in full lock so when he spins around it will keep him to the wall rather then him spinning back down the track and getting t-boned. I still think this is a flaw in the GPL engine. -- Solo1 C-Modified (CASC-OR/BARC) http://www.barc-oc.com http://www.casc.on.ca

I don't know why you have a hard time believing this. By turning hard left the driver can throw the car into a four wheel slide. It is not something that comes natural to any of us including the pro drivers. So you will not see it too often. I will always try and steer with the slide. But that is just out of habit. -- Kevin Anderson [email hidden] "Alan Orton" <[email hidden]> wrote in message news:[email hidden]... > Until you show me some real proof of this, James. I won't believe you. > ;) > Any mpgs or pics out there where is shows a driver turning in full > lock(Not opposite lock) to save a spin? If the spin was too far gone I > could see a Cup driver puting in full lock so when he spins around it > will keep him to the wall rather then him spinning back down the track > and getting t-boned. > I still think this is a flaw in the GPL engine. > > > > -- > Solo1 C-Modified (CASC-OR/BARC) > http://www.barc-oc.com > http://www.casc.on.ca

I have a hard time believing it because I have never seen anyone do it outside the realms of GPL and N4. Can you prove it? If it took us sim racers a couple months to figure it out and do it by habit I'm sure the pro's would of caught on about 40 years ago. Kevin Anderson wrote:

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> > I don't know why you have a hard time believing this. By turning hard left > the driver can throw the car into a four wheel slide. It is not something > that comes natural to any of us including the pro drivers. So you will not > see it too often. I will always try and steer with the slide. But that is > just out of habit. > > -- > Kevin Anderson > [email hidden] > > "Alan Orton" <[email hidden]> wrote in message > news:[email hidden]... > > Until you show me some real proof of this, James. I won't believe you. > > ;) > > Any mpgs or pics out there where is shows a driver turning in full > > lock(Not opposite lock) to save a spin? If the spin was too far gone I > > could see a Cup driver puting in full lock so when he spins around it > > will keep him to the wall rather then him spinning back down the track > > and getting t-boned. > > I still think this is a flaw in the GPL engine. > > > > > > > > -- > > Solo1 C-Modified (CASC-OR/BARC) > > http://www.barc-oc.com > > http://www.casc.on.ca

-- Solo1 C-Modified (CASC-OR/BARC) 76 Trans-Am 600+hp http://www.barc-oc.com http://www.casc.on.ca

>"Alan Orton" <[email hidden]> wrote > I have a hard time believing it because I have never seen anyone do it > outside the realms of GPL and N4. > Can you prove it? Oh please Alan... watch some bloody in-car racing from time to time, and review carefully slides that pass the PNR (point of no return) Guys I'm trying to get the guys on Jacob's newsgroup to find out the truth about racing physics. They seem to have some limited knowledge of the whole situation. They all think that when you pass the PNR while sliding steering into the slide won't help, and that continuing to counter-steer will help you get your rear back on track. We all know it's totally false, but let's remember those Stock-cars guys have been assimilated from the old game engine for almost a decade. They have learned the wrong way, and it's hard for them to think correctly. It will be a long processus for them. Doug Milliken, where are you? ;-) To the rescue please! -- -- Fran�ois M�nard <ymenard> -- May the Downforce be with you... -- http://www.WeRace.net -- People think it must be fun to be a super genius, but they don't realise how hard it is to put up with all the idiots in the world.

"They all think that when you pass the PNR while sliding steering into the slide won't help, and that continuing to counter-steer will help you get your rear back on track." Isn't counter steering and steering into the slide the same thing? I thought it was - The rear slides to the right so you turn to the right. -- Solo1 C-Modified (CASC-OR/BARC) http://www.barc-oc.com http://www.casc.on.ca

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>"Alan Orton" <[email hidden]> wrote > "They all think that when you pass the PNR while sliding steering into > the slide won't help, and that continuing to counter-steer will help > you get your rear back on track." > > Isn't counter steering and steering into the slide the same thing? I > thought it was - The rear slides to the right so you turn to the right.

Sorry that was a typo Alan, I obviously meant "steering out of the slide won't..." -- -- Fran�ois M�nard <ymenard> -- May the Downforce be with you... -- http://www.WeRace.net -- People think it must be fun to be a super genius, but they don't realise how hard it is to put up with all the idiots in the world.

ymenard wrote:

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> > >"Alan Orton" <[email hidden]> wrote > > "They all think that when you pass the PNR while sliding steering into > > the slide won't help, and that continuing to counter-steer will help > > you get your rear back on track." > > > > Isn't counter steering and steering into the slide the same thing? I > > thought it was - The rear slides to the right so you turn to the right. > > Sorry that was a typo Alan, I obviously meant "steering out of the slide > won't..."

You have me all confused now,hehe. Steering out of the slide is the same thing as saying counter steering or steering into the skid, is it not? Damn english. ;) Turning with the spin is what this is all about. In N4 if the rear looses traction and it starts slipping to the right you turn the wheel to the left(tightening the turn) to correct a loose condition or in other words turning with the slide. That is not realistic. -- Solo1 C-Modified (CASC-OR/BARC) http://www.barc-oc.com http://www.casc.on.ca

>"Alan Orton" <[email hidden]> wrote > In N4 if the rear looses traction and it starts slipping to the right > you turn the wheel to the left(tightening the turn) to correct a loose > condition or in other words turning with the slide. That is not > realistic. Yes, it is when you pass the PNR!!! If in this situation you continue to turn the wheel to the right, you will just induce more the spin! Basic racing physics here Alan. -- -- Fran�ois M�nard <ymenard> -- May the Downforce be with you... -- http://www.WeRace.net -- People think it must be fun to be a super genius, but they don't realise how hard it is to put up with all the idiots in the world.

Alan, I checked out your N4 setups at bhmotorsports, the Dover setup is nice, but the Mich setup is wayyyyyyyyyyyyyyyyyyyy loose. I am amazed anyone could race with that, LOL When you can, how about posting a replay of you running with that setup. Are you entering the turns deep or starting wide then turning in ? thanx, Rich#8 On Sun, 24 Dec 2000 20:41:41 GMT, Alan Orton <[email hidden]> wrote:

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>ymenard wrote: >> >> >"Alan Orton" <[email hidden]> wrote >> > "They all think that when you pass the PNR while sliding steering into >> > the slide won't help, and that continuing to counter-steer will help >> > you get your rear back on track." >> > >> > Isn't counter steering and steering into the slide the same thing? I >> > thought it was - The rear slides to the right so you turn to the right. >> >> Sorry that was a typo Alan, I obviously meant "steering out of the slide >> won't..." > >You have me all confused now,hehe. Steering out of the slide is the same >thing as saying counter steering or steering into the skid, is it not? >Damn english. ;) > >Turning with the spin is what this is all about. > >In N4 if the rear looses traction and it starts slipping to the right >you turn the wheel to the left(tightening the turn) to correct a loose >condition or in other words turning with the slide. That is not >realistic. > > > >-- >Solo1 C-Modified (CASC-OR/BARC) >http://www.barc-oc.com >http://www.casc.on.ca

I 'noticed' this but thought it was just my feeble driving. Rarely in N4 can I save a slide by using the PROPER method of counter-steering.(a technique I learned years ago in SODA: Off road Racing.) So If I am in trouble..The back end sliding away, I should ignore my instincts and turn towards the inner wall? hmmmm This will be hard to convince my hands and feet to do...but I'll give it a try. dave henrie "ymenard" <[email hidden]> wrote in message news:fqt16.14646$[email hidden]...

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> >"Alan Orton" <[email hidden]> wrote > > In N4 if the rear looses traction and it starts slipping to the right > > you turn the wheel to the left(tightening the turn) to correct a loose > > condition or in other words turning with the slide. That is not > > realistic. > > Yes, it is when you pass the PNR!!! If in this situation you continue to > turn the wheel to the right, you will just induce more the spin! Basic > racing physics here Alan. > > > > > -- > -- Fran�ois M�nard <ymenard> > -- May the Downforce be with you... > -- http://www.WeRace.net > -- People think it must be fun to be a super genius, but they don't

realise > how hard it is to put up with all the idiots in the world. > > >

I saw an mpeg somewhere of mika in F1 getting the car loose in the wet and he put in full lock in the direction that seemed like it would make him spin faster, but because he went way past the optimal slip angle of the front tires, they lost enough grip to keep the slide neutral until he lost enough speed for the rear tires to regain traction...I will see if I can find the video. JB "Alan Orton" <[email hidden]> wrote in message news:[email hidden]...

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> Until you show me some real proof of this, James. I won't believe you. > ;) > Any mpgs or pics out there where is shows a driver turning in full > lock(Not opposite lock) to save a spin? If the spin was too far gone I > could see a Cup driver puting in full lock so when he spins around it > will keep him to the wall rather then him spinning back down the track > and getting t-boned. > I still think this is a flaw in the GPL engine. > > > > -- > Solo1 C-Modified (CASC-OR/BARC) > http://www.barc-oc.com > http://www.casc.on.ca

This is also similar to locking up all 4 tires when spinning...it stops the spin by making ALL tires not work...then once you lose enough speed where all tires can regain traction, you unlock the tires and go... JB

If using opposite lock (back end is sliding to the right in a left hand turn so you turn the wheel right) isn't working for you, you are probably catching the slide too late. If you anticipate the slide, you can normally snap over to opposite lock fast enough. If you have to wait to see the car rotating around, it is probably too late since it is tough to stop the inertia of the rear sliding around...so instead of trying to stop the rear from sliding more, you turn the wheels left which takes a lot of grip away from the front...most likely taking it to lower than the rear, so the car begins to slide with all 4 wheels...maybe not in the direction you want to go, but it is more controlled than spinning. JB "Dave Henrie" <[email hidden]> wrote in message news:X7u16.190304$[email hidden]... > I 'noticed' this but thought it was just my feeble driving. Rarely inN4

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> can I save a slide by using the PROPER method of counter-steering.(a > technique I learned years ago in SODA: Off road Racing.) > So If I am in trouble..The back end sliding away, I should ignore my > instincts and turn towards the inner wall? hmmmm > This will be hard to convince my hands and feet to do...but I'll give it a > try. > dave henrie > "ymenard" <[email hidden]> wrote in message > news:fqt16.14646$[email hidden]... > > >"Alan Orton" <[email hidden]> wrote > > > In N4 if the rear looses traction and it starts slipping to the right > > > you turn the wheel to the left(tightening the turn) to correct a loose > > > condition or in other words turning with the slide. That is not > > > realistic. > > > > Yes, it is when you pass the PNR!!! If in this situation you continue to > > turn the wheel to the right, you will just induce more the spin! Basic > > racing physics here Alan. > > > > > > > > > > -- > > -- Fran�ois M�nard <ymenard> > > -- May the Downforce be with you... > > -- http://www.WeRace.net > > -- People think it must be fun to be a super genius, but they don't > realise > > how hard it is to put up with all the idiots in the world. > > > > > > >

In the rain is a different matter. Maybe he was trying to hydroplane the front tires? Wet weather is totaly different then the dry. Show me a mpeg of him doing it in the dry. Wosco wrote:

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> > I saw an mpeg somewhere of mika in F1 getting the car loose in the wet and > he put in full lock in the direction that seemed like it would make him spin > faster, but because he went way past the optimal slip angle of the front > tires, they lost enough grip to keep the slide neutral until he lost enough > speed for the rear tires to regain traction...I will see if I can find the > video. > > JB > > "Alan Orton" <[email hidden]> wrote in message > news:[email hidden]... > > Until you show me some real proof of this, James. I won't believe you. > > ;) > > Any mpgs or pics out there where is shows a driver turning in full > > lock(Not opposite lock) to save a spin? If the spin was too far gone I > > could see a Cup driver puting in full lock so when he spins around it > > will keep him to the wall rather then him spinning back down the track > > and getting t-boned. > > I still think this is a flaw in the GPL engine. > > > > > > > > -- > > Solo1 C-Modified (CASC-OR/BARC) > > http://www.barc-oc.com > > http://www.casc.on.ca

-- Solo1 C-Modified (CASC-OR/BARC) 76 Trans-Am 600+hp http://www.barc-oc.com http://www.casc.on.ca

HI, Rich. It all has to do with driving style. I've been told the Dover setup is undriveable but you think it is nice and others think the same way for the Michgan setup. Some thing it is good some say undriveable. I'll send you a replay with that setup. If I see you on IRF I'll race you with the same setup. I enter the corners pretty deep. In turn 1 I slightly lift just before the really dark groove and big bump/dip in the road. Rich#8 wrote:

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> > Alan, > > I checked out your N4 setups at bhmotorsports, the Dover setup is > nice, but the Mich setup is wayyyyyyyyyyyyyyyyyyyy loose. I am amazed > anyone could race with that, LOL > > When you can, how about posting a replay of you running with that > setup. > > Are you entering the turns deep or starting wide then turning in ? > > thanx, > > Rich#8 > > On Sun, 24 Dec 2000 20:41:41 GMT, Alan Orton <[email hidden]> wrote: > > >ymenard wrote: > >> > >> >"Alan Orton" <[email hidden]> wrote > >> > "They all think that when you pass the PNR while sliding steering into > >> > the slide won't help, and that continuing to counter-steer will help > >> > you get your rear back on track." > >> > > >> > Isn't counter steering and steering into the slide the same thing? I > >> > thought it was - The rear slides to the right so you turn to the right. > >> > >> Sorry that was a typo Alan, I obviously meant "steering out of the slide > >> won't..." > > > >You have me all confused now,hehe. Steering out of the slide is the same > >thing as saying counter steering or steering into the skid, is it not? > >Damn english. ;) > > > >Turning with the spin is what this is all about. > > > >In N4 if the rear looses traction and it starts slipping to the right > >you turn the wheel to the left(tightening the turn) to correct a loose > >condition or in other words turning with the slide. That is not > >realistic. > > > > > > > >-- > >Solo1 C-Modified (CASC-OR/BARC) > >http://www.barc-oc.com > >http://www.casc.on.ca

-- Solo1 C-Modified (CASC-OR/BARC) 76 Trans-Am 600+hp http://www.barc-oc.com http://www.casc.on.ca

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>Until you show me some real proof of this, James. I won't believe you. >;) >Any mpgs or pics out there where is shows a driver turning in full >lock(Not opposite lock) to save a spin? If the spin was too far gone I >could see a Cup driver puting in full lock so when he spins around it >will keep him to the wall rather then him spinning back down the track >and getting t-boned. >I still think this is a flaw in the GPL engine.

This isn't a flaw at all in driving sims. A tire develops its side force from slip angle. Say for instance your front tire is moving north (0 degree compass heading), but is pointed 5 degrees to the right. You'll get a certain amount of sideforce. This will increase as slip angle increases up to a point, then drop off (according to some test data). The sideforce may peak at 10 degrees of slip angle for a street tire, or perhaps 3-5 degrees for some high performance racing tires. If you take a look at a graph of this, it looks something like this: http://www.ika.rwth-aachen.de/publikat/tk-avec/fig02.gif See where the peak is? If you turn the wheel past that area, you're actually getting LESS grip. Some tire data shows the force leveling off rather than dipping after the peak is reached (as in the picture). However, in this case, you'll still see progressively less turning force as steering input is increased. Why? This force is more or less perpendicular to the tire (hence, "sideforce"). Steering the front wheels at a 45 degree angle may result in maximum force, but 70.7% of the total force is pushing sideways relative to the front end of the vehicle, and 70.7% of the total force is acting as drag, slowing the vehicle. Turn the front wheels 60 degrees. Now you've got even less of the force pushing sideways, and more pushing towards the rear of the car. (This is a sine/cosine relationship.) So basically, I think there are two main factors that cause this "steering into the spin to catch it" phenomenon to often times be true in both driving sims and the real world: 1. Once the optimum slip angle is passed, many tires develop LESS sideforce. 2. The force's direction is changing as steering input is altered. Increasing the steering input causes the force to be applied progressively towards the rear of the car, leaving less pointing sideways to actually turn the vehicle. Make sense? How much sideforce will your tires make if they're turned at a 90 degree angle? Absolutely none, but they'll sure slow down the car in a hurry! Todd Wasson --- Performance Simulations Drag Racing and Top Speed Prediction Software http://PerformanceSimulations.Com

J. Todd Wasson wrote:

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> > >Until you show me some real proof of this, James. I won't believe you. > >;) > >Any mpgs or pics out there where is shows a driver turning in full > >lock(Not opposite lock) to save a spin? If the spin was too far gone I > >could see a Cup driver puting in full lock so when he spins around it > >will keep him to the wall rather then him spinning back down the track > >and getting t-boned. > >I still think this is a flaw in the GPL engine. > > This isn't a flaw at all in driving sims. A tire develops its side force > from slip angle. Say for instance your front tire is moving north (0 degree > compass heading), but is pointed 5 degrees to the right. You'll get a certain > amount of sideforce. This will increase as slip angle increases up to a point, > then drop off (according to some test data). The sideforce may peak at 10 > degrees of slip angle for a street tire, or perhaps 3-5 degrees for some high > performance racing tires. If you take a look at a graph of this, it looks > something like this: > > http://www.ika.rwth-aachen.de/publikat/tk-avec/fig02.gif > > See where the peak is? If you turn the wheel past that area, you're actually > getting LESS grip. Some tire data shows the force leveling off rather than > dipping after the peak is reached (as in the picture). However, in this case, > you'll still see progressively less turning force as steering input is > increased. Why? This force is more or less perpendicular to the tire (hence, > "sideforce"). Steering the front wheels at a 45 degree angle may result in > maximum force, but 70.7% of the total force is pushing sideways relative to the > front end of the vehicle, and 70.7% of the total force is acting as drag, > slowing the vehicle. Turn the front wheels 60 degrees. Now you've got even > less of the force pushing sideways, and more pushing towards the rear of the > car. (This is a sine/cosine relationship.) > > So basically, I think there are two main factors that cause this "steering > into the spin to catch it" phenomenon to often times be true in both driving > sims and the real world: > > 1. Once the optimum slip angle is passed, many tires develop LESS sideforce. > > 2. The force's direction is changing as steering input is altered. > Increasing the steering input causes the force to be applied progressively > towards the rear of the car, leaving less pointing sideways to actually turn > the vehicle. > > Make sense? How much sideforce will your tires make if they're turned at a > 90 degree angle? Absolutely none, but they'll sure slow down the car in a > hurry! > > Todd Wasson > --- > Performance Simulations > Drag Racing and Top Speed Prediction > Software > http://PerformanceSimulations.Com

What would happen in a loose car where the rear end is traveling faster then the front and then you crank the front wheels(not counter steer) and induce lots of under steer drag and transfer even more weight to the front? It will trip up the car and you will spin in a hurry. The front wouldn't wash out and prevent a spin. Try Viper Racing with 35 degree steering. Viper models this area better then GPL and N4, imo. You can get into some nasty tank slappers in Viper if you are a little behind the steering. In the last 2 years I can't even remember being in a tank slapper with GPL and I haven't yet in N4. When you crank on opposite lock at moderate slip angles with the GPL engine you will spin every time so you can't even get in one if you tried. You can be in little wiggles but not tank slappers. I've been in 40 degree yaw tank slappers with my real car for 5 or 6 slaps, it is a good way to scare yourself. I was just screwing around and tried to see how big of a slide I could correct with out lifting. It didn't help that my car at the time had cheap stock seats and cheap stock seat belts as I was being thrown around in the car. Pretty hard to steer when you're upper torso is constantly being tossed into the passenger seat and then get slammed back into the drivers door. It was fun though. :) Try Viper with 35 degree steering, you will notice a difference. -- Solo1 C-Modified (CASC-OR/BARC) http://www.barc-oc.com http://www.casc.on.ca

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>What would happen in a loose car where the rear end is traveling faster >then the front and then you crank the front wheels(not counter steer) >and induce lots of under steer drag and transfer even more weight to the >front? It will trip up the car and you will spin in a hurry. The front >wouldn't wash out and prevent a spin. > >Try Viper Racing with 35 degree steering. Viper models this area better >then GPL and N4, imo. >You can get into some nasty tank slappers in Viper if you are a little >behind the steering. In the last 2 years I can't even remember being in >a tank slapper with GPL and I haven't yet in N4. When you crank on >opposite lock at moderate slip angles with the GPL engine you will spin >every time so you can't even get in one if you tried. You can be in >little wiggles but not tank slappers. I've been in 40 degree yaw tank >slappers with my real car for 5 or 6 slaps, it is a good way to scare >yourself. I was just screwing around and tried to see how big of a slide >I could correct with out lifting. It didn't help that my car at the time >had cheap stock seats and cheap stock seat belts as I was being thrown >around in the car. Pretty hard to steer when you're upper torso is >constantly being tossed into the passenger seat and then get slammed >back into the drivers door. It was fun though. :) > >Try Viper with 35 degree steering, you will notice a difference. >

Hmmm... I'll be darned. Good point. By tank slapper, I assume you mean the wild left and right swinging you can get when trying to get the car back under control, right? A friend and I did that in his ' 71 Firebird, starting at 100-110 mph, and finally spinning three times at the end of a few of those. Pretty wild ride down the freeway! Can't believe we ended up right in the middle of the road without hitting anything. (Dumb kids!) Yes, I suppose the forward weight transfer could more than make up for what I was talking about. I don't have Viper Racing, but remember battling that one with Hard/Race Drivin' in the arcade. I haven't had that happen in any PC sim, now that you mention it. I wonder what the difference is. Todd Wasson --- Performance Simulations Drag Racing and Top Speed Prediction Software http://PerformanceSimulations.Com

> Hmmm... I'll be darned. Good point. By tank slapper, I assume you mean the > wild left and right swinging you can get when trying to get the car back under > control, right? A friend and I did that in his ' 71 Firebird, Thanks. :) Yep, that is what I meant. The violent slides to the right then left then right,ect... caused by over correcting. 76 Trans-Am here with a modified 455ci(500hp) 71 Firebirds are nice :) -- Solo1 C-Modified (CASC-OR/BARC) http://www.barc-oc.com http://www.casc.on.ca

Alan Orton wrote:

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> > Try Viper Racing with 35 degree steering. Viper models this area better > then GPL and N4, imo. > You can get into some nasty tank slappers in Viper if you are a little > behind the steering. In the last 2 years I can't even remember being in > a tank slapper with GPL and I haven't yet in N4. When you crank on > opposite lock at moderate slip angles with the GPL engine you will spin > every time so you can't even get in one if you tried. You can be in > little wiggles but not tank slappers. I've been in 40 degree yaw tank > slappers with my real car for 5 or 6 slaps, it is a good way to scare > yourself. I was just screwing around and tried to see how big of a slide > I could correct with out lifting. It didn't help that my car at the time > had cheap stock seats and cheap stock seat belts as I was being thrown > around in the car. Pretty hard to steer when you're upper torso is > constantly being tossed into the passenger seat and then get slammed > back into the drivers door. It was fun though. :) >

I've done a few tank slappers at the road courses in N4 :) Unfortunately they almost always end up slamming head on into a wall. I believe part of being able to produce a good tank slapper is the ability to turn the front wheels far enough to overcorrect for a slide. In the game with our feeble controllers that barely turn 120 degrees at most in one direction, it's very hard to turn the front wheels far enough to catch a slide. At the road courses I run 12:1 steering ratio, and that's barely enough to catch slides. At the ovals with steering ratios of 24:1 or 30:1 or so that just isn't enough steering lock available to properly catch a big slide, or produce tank slappers. I catch the big slides by applying a bit of throttle, and stabbing the brakes, to cause the fronts to lock up enough to straighten the car out. Once I had a really good tank slapper in my real car - not long after I bought it I was pulling out left onto a road, but the turbo kicked in rather unexpectedly in 1st gear and instantly broke traction. This wouldn't normally have been an issue, except that I *really* wasn't expecting it, and the steering wheel pulled out of my hands :) the car fishtailed about 5 times before I managed to recatch the wheel - it's very hard to grab the steering wheel when it's turning 720 degrees in each direction every second! :) I've noticed in GPL that you can get some huge tank slappers by duplicating this trick of letting go of the steering wheel if you're using FF. > Solo1 C-Modified (CASC-OR/BARC) Solo2 E-Modified MR2.

> I've done a few tank slappers at the road courses in N4 :) Road courses for N4?!? Have I missed something? Are you an N4 beta tester or has somebody converted GPL tracks for use with the demo? -Dirt- 2000 White/Red CBR929RR **Jesus saves sinners and redeems them for valuable cash prizes** Sent via Deja.com http://www.deja.com/

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> I've done a few tank slappers at the road courses in N4 :) Unfortunately > they almost always end up slamming head on into a wall. > I believe part of being able to produce a good tank slapper is the > ability to turn the front wheels far enough to overcorrect for a slide. > In the game with our feeble controllers that barely turn 120 degrees > at most in one direction, it's very hard to turn the front wheels far > enough to catch a slide. At the road courses I run 12:1 steering ratio, > and that's barely enough to catch slides. At the ovals with steering > ratios of 24:1 or 30:1 or so that just isn't enough steering lock > available to properly catch a big slide, or produce tank slappers. > I catch the big slides by applying a bit of throttle, and stabbing > the brakes, to cause the fronts to lock up enough to straighten the > car out. > Once I had a really good tank slapper in my real car - not long > after I bought it I was pulling out left onto a road, but the turbo > kicked in rather unexpectedly in 1st gear and instantly broke traction. > This wouldn't normally have been an issue, except that I *really* wasn't > expecting it, and the steering wheel pulled out of my hands :) the car > fishtailed about 5 times before I managed to recatch the wheel - it's > very hard to grab the steering wheel when it's turning 720 degrees in > each direction every second! :) > I've noticed in GPL that you can get some huge tank slappers by > duplicating this trick of letting go of the steering wheel if you're > using FF. > > > Solo1 C-Modified (CASC-OR/BARC) > > Solo2 E-Modified MR2.

Maybe that is something you guys at Papy should look into, Grant? Could you find out what max steering lock is on a cup car and give us that option? Like front tires pointing at 35 or 45 or 50 degree,ect. We could work the rest with non linear/linear steering to suit our rigs. I'm using 35 degree steering in Viper with a worn out T2 that has a lock to lock of 180 degree's. Using non linear and it works great. Just curious but doesn't steering ratio mean the amount of turns you have to do on your wheel to get full lock? It doesn't effect the amount of lock, does it? "I've noticed in GPL that you can get some huge tank slappers by duplicating this trick of letting go of the steering wheel if you're using FF." Wonder if FF latency helped it along? J/K :) Thanks for responding, Grant. :) -- Solo1 C-Modified (CASC-OR/BARC) http://www.barc-oc.com http://www.casc.on.ca

i should send you my slide catch opposite lock rpys.....in the rpys you sent to me, you were far too late applying the opposite lock to do anything, which is why the 'turn in more' approach was working (as people have said, its loosing traction in another way), plus your speed was higher in the inevitable 'opposite lock does nothing' crashes......eek tank slappers are just nasty in gpl, damn weak suspension..... and heres another person saying theyve seen an f1 driver turn in more and brake to bring the front around, so it happens in the wet, when the cars have little grip, isnt that compareable with 67 f1? pez Alan Orton <[email hidden]> wrote in message news:[email hidden]...

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> J. Todd Wasson wrote: > > > > >Until you show me some real proof of this, James. I won't believe you. > > >;) > > >Any mpgs or pics out there where is shows a driver turning in full > > >lock(Not opposite lock) to save a spin? If the spin was too far gone I > > >could see a Cup driver puting in full lock so when he spins around it > > >will keep him to the wall rather then him spinning back down the track > > >and getting t-boned. > > >I still think this is a flaw in the GPL engine. > > > > This isn't a flaw at all in driving sims. A tire develops its side

force > > from slip angle. Say for instance your front tire is moving north (0degree > > compass heading), but is pointed 5 degrees to the right. You'll get acertain > > amount of sideforce. This will increase as slip angle increases up to apoint, > > then drop off (according to some test data). The sideforce may peak at10 > > degrees of slip angle for a street tire, or perhaps 3-5 degrees for somehigh > > performance racing tires. If you take a look at a graph of this, itlooks > > something like this: > > > > http://www.ika.rwth-aachen.de/publikat/tk-avec/fig02.gif > > > > See where the peak is? If you turn the wheel past that area, you'reactually > > getting LESS grip. Some tire data shows the force leveling off ratherthan > > dipping after the peak is reached (as in the picture). However, in thiscase, > > you'll still see progressively less turning force as steering input is > > increased. Why? This force is more or less perpendicular to the tire(hence, > > "sideforce"). Steering the front wheels at a 45 degree angle may resultin > > maximum force, but 70.7% of the total force is pushing sideways relativeto the > > front end of the vehicle, and 70.7% of the total force is acting asdrag, > > slowing the vehicle. Turn the front wheels 60 degrees. Now you've goteven > > less of the force pushing sideways, and more pushing towards the rear ofthe > > car. (This is a sine/cosine relationship.) > > > > So basically, I think there are two main factors that cause this"steering > > into the spin to catch it" phenomenon to often times be true in bothdriving > > sims and the real world: > > > > 1. Once the optimum slip angle is passed, many tires develop LESSsideforce. > > > > 2. The force's direction is changing as steering input is altered. > > Increasing the steering input causes the force to be appliedprogressively > > towards the rear of the car, leaving less pointing sideways to actuallyturn > > the vehicle. > > > > Make sense? How much sideforce will your tires make if they're turnedat a > > 90 degree angle? Absolutely none, but they'll sure slow down the car ina

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> > hurry! > > > > Todd Wasson > > --- > > Performance Simulations > > Drag Racing and Top Speed Prediction > > Software > > http://PerformanceSimulations.Com > > What would happen in a loose car where the rear end is traveling faster > then the front and then you crank the front wheels(not counter steer) > and induce lots of under steer drag and transfer even more weight to the > front? It will trip up the car and you will spin in a hurry. The front > wouldn't wash out and prevent a spin. > > Try Viper Racing with 35 degree steering. Viper models this area better > then GPL and N4, imo. > You can get into some nasty tank slappers in Viper if you are a little > behind the steering. In the last 2 years I can't even remember being in > a tank slapper with GPL and I haven't yet in N4. When you crank on > opposite lock at moderate slip angles with the GPL engine you will spin > every time so you can't even get in one if you tried. You can be in > little wiggles but not tank slappers. I've been in 40 degree yaw tank > slappers with my real car for 5 or 6 slaps, it is a good way to scare > yourself. I was just screwing around and tried to see how big of a slide > I could correct with out lifting. It didn't help that my car at the time > had cheap stock seats and cheap stock seat belts as I was being thrown > around in the car. Pretty hard to steer when you're upper torso is > constantly being tossed into the passenger seat and then get slammed > back into the drivers door. It was fun though. :) > > Try Viper with 35 degree steering, you will notice a difference. > > > -- > Solo1 C-Modified (CASC-OR/BARC) > http://www.barc-oc.com > http://www.casc.on.ca

Chris Cavin wrote: > > > I've done a few tank slappers at the road courses in N4 :) > > Road courses for N4?!? Have I missed something? Are you an N4 beta > tester or has somebody converted GPL tracks for use with the demo? Pssst, Chris, Grant works for Papy........:-) Beers and cheers (uncle) Goy http://www.theuspits.com http://www.teammirage.com "Mountain climbing, auto racing and bullfighting are the only true sports...all others are games." --Ernest Hemingway--

> > > I've done a few tank slappers at the road courses in N4 :) > > > > Road courses for N4?!? Have I missed something? Are you an N4 beta > > tester or has somebody converted GPL tracks for use with the demo? > > Pssst, Chris, Grant works for Papy........:-) Umm... <sheepish grin> That would sorta explain it, then, wouldn't it? Why doesn't anybody *TELL* me these things before I do that? -Dirt- 2000 White/Red CBR929RR **Jesus saves sinners and redeems them for valuable cash prizes** Sent via Deja.com http://www.deja.com/

On 25 Dec 2000 06:54:23 GMT, [email hidden] (J. Todd Wasson) wrote: > Hmmm... I'll be darned. Good point. By tank slapper, I assume you mean the >wild left and right swinging you can get when trying to get the car back under >control, right? A friend and I did that in his ' 71 Firebird, starting at [snip] That term comes from motorcycle racing, and is actually misused here, although it is pretty descriptive of what happens when you over compensate for oversteer. When you think of a fast left-right oscillation on a motorcycle, the meaning of the word Tank Slapper becomes obvious. Most people have probably seen footage of a race bike going nearly straight while the front end spasmodically vibrates left and right. They often occur when you lose traction at the back while under power. If the back comes around too far then bites, you progress from tank slapper to High Side (think of rider being launched over the the bike like a catapault. If the back comes around and never regains traction, you "Low Side". This is when you see the guy sliding down the track on his ass, frantically flapping arms and legs to avoid running into the motorcycle which is sliding along basically the same trajectory. Hilarious stuff to watch, not so hilarious to experience. ;-) Tim

Alexpez wrote:

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> > i should send you my slide catch opposite lock rpys.....in the rpys you sent > to me, you were far too late applying the opposite lock to do anything, > which is why the 'turn in more' approach was working (as people have said, > its loosing traction in another way), plus your speed was higher in the > inevitable 'opposite lock does nothing' crashes......eek > tank slappers are just nasty in gpl, damn weak suspension..... > > and heres another person saying theyve seen an f1 driver turn in more and > brake to bring the front around, so it happens in the wet, when the cars > have little grip, isnt that compareable with 67 f1? > > pez

I don't know, Pez. I guess I'm just stubborn. ;) But I still think there is less front tire resistance when it is pointing up the road(counter steering) then a tire at a 40 degree slip angle in the wrong direction. If I couldn't save the spin when the rolling resistance of the tire is the main drag component then I shouldn't be able to save it by inducing lots of drag and cornering force in the wrong direction. I would like the see that mpeg of Mika doing this if you can find it. -- Solo1 C-Modified (CASC-OR/BARC) http://www.barc-oc.com http://www.casc.on.ca

actually Alan you are right, sort of, however if you turn far enough away from the slide you can get the fronts to let go and allow them to overtake the rears. As a sliding wheel has no directional stability, by turning away from the slide you can get the fronts to slide enough to match the rears. Thereby allowing you to slow the car enough to get it under control. By turning away from the corner you are reducing the drag not increasing it as you are when you counter-steer or turn into the slide. You can also do this by stabbing the brakes and locking up the fronts, however if you lock up all four it also brings in the inertia of the sliding rear of the car and you may slowly continue to rotate. Hope this makes sense Shane Alan Orton <[email hidden]> wrote in message news:[email hidden]... > Alexpez wrote: > > > > i should send you my slide catch opposite lock rpys.....in the rpys yousent > > to me, you were far too late applying the opposite lock to do anything, > > which is why the 'turn in more' approach was working (as people havesaid, > > its loosing traction in another way), plus your speed was higher in the > > inevitable 'opposite lock does nothing' crashes......eek > > tank slappers are just nasty in gpl, damn weak suspension..... > > > > and heres another person saying theyve seen an f1 driver turn in moreand

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> > brake to bring the front around, so it happens in the wet, when the cars > > have little grip, isnt that compareable with 67 f1? > > > > pez > > > I don't know, Pez. I guess I'm just stubborn. ;) > But I still think there is less front tire resistance when it is > pointing up the road(counter steering) then a tire at a 40 degree slip > angle in the wrong direction. > > If I couldn't save the spin when the rolling resistance of the tire is > the main drag component then I shouldn't be able to save it by inducing > lots of drag and cornering force in the wrong direction. > > I would like the see that mpeg of Mika doing this if you can find it. > > -- > Solo1 C-Modified (CASC-OR/BARC) > http://www.barc-oc.com > http://www.casc.on.ca

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>That term comes from motorcycle racing, and is actually misused here, >although it is pretty descriptive of what happens when you over >compensate for oversteer. > >When you think of a fast left-right oscillation on a motorcycle, the >meaning of the word Tank Slapper becomes obvious. >Most people have probably seen footage of a race bike going nearly >straight while the front end spasmodically vibrates left and right. > >They often occur when you lose traction at the back while under power. >If the back comes around too far then bites, you progress from tank >slapper to High Side (think of rider being launched over the the bike >like a catapault. If the back comes around and never regains traction, >you "Low Side". This is when you see the guy sliding down the track on >his ass, frantically flapping arms and legs to avoid running into the >motorcycle which is sliding along basically the same trajectory. > >Hilarious stuff to watch, not so hilarious to experience. ;-)

Oh yes, I've seen that on TV. Doesn't look fun at all! Todd Wasson --- Performance Simulations Drag Racing and Top Speed Prediction Software http://PerformanceSimulations.Com

On Mon, 25 Dec 2000 21:48:41 GMT, Alan Orton <[email hidden]> wrote:

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>Maybe that is something you guys at Papy should look into, Grant? >Could you find out what max steering lock is on a cup car and give us >that option? Like front tires pointing at 35 or 45 or 50 degree,ect. We >could work the rest with non linear/linear steering to suit our rigs. > >I'm using 35 degree steering in Viper with a worn out T2 that has a lock >to lock of 180 degree's. Using non linear and it works great. > >Just curious but doesn't steering ratio mean the amount of turns you >have to do on your wheel to get full lock? It doesn't effect the amount >of lock, does it? >

It depends on how you are thinking of steering lock. On normal cars the steering is probably limited because the front wheels themselves will only turn a certain distance before the steering rack hits it's limits. Changing the steering ratio would do as you say. But in N4 it doesn't work like that - the steering wheel attached to your desk isn't adjustable, so the available wheel lock is simply however far the wheels will turn given the current steering ratio when you turn your PC steering wheel all the way. So if you want your wheels to be able to turn further, give yourself a faster steering ratio. I'm not sure how the steering ratio maps to degrees of wheel lock. >"I've noticed in GPL that you can get some huge tank slappers by >duplicating this trick of letting go of the steering wheel if you're >using FF." > >Wonder if FF latency helped it along? J/K :) >Most likely :)

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> It depends on how you are thinking of steering lock. On normal cars the > steering is probably limited because the front wheels themselves will only > turn a certain distance before the steering rack hits it's limits. Changing the > steering ratio would do as you say. But in N4 it doesn't work like that - the > steering wheel attached to your desk isn't adjustable, so the available wheel > lock is simply however far the wheels will turn given the current steering ratio > when you turn your PC steering wheel all the way. So if you want your wheels to > be able to turn further, give yourself a faster steering ratio. I'm not sure how > the steering ratio maps to degrees of wheel lock. > > >"I've noticed in GPL that you can get some huge tank slappers by > >duplicating this trick of letting go of the steering wheel if you're > >using FF." > > > >Wonder if FF latency helped it along? J/K :) > > > Most likely :)

I'm now running 12:1 ratio with N4 on the ovals but decreased the linear steering to 30% and still did a 38.1 in a race at Michigan. The sensitivity is no different now then when I had 24:1+ steering ratio and 50% linear. But I now have a lot more steering angle from mid to max lock but it still doesn't counter steer properly. You could run 1:1 with 10% linear and it would work but I still doubt it would counter steer properly. ;) That is until you generate a slip angle by counter steering but then you would go head on into the wall in a blink of an eye and not even Jumping Jack Flash on 20 hits of speed could do anything about it. It should be interesting when WSC comes out to see how it's tire and suspension model compares to the GPL engine. ;) Oh well, probably another year to wait before the show down. Atleast it won't affect N4 sales. -- Solo1 C-Modified (CASC-OR/BARC) http://www.barc-oc.com http://www.casc.on.ca

Shane Lowry wrote:

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> > actually Alan you are right, sort of, however if you turn far enough away > from the slide you can get the fronts to let go and allow them to overtake > the rears. As a sliding wheel has no directional stability, by turning away > from the slide you can get the fronts to slide enough to match the rears. > Thereby allowing you to slow the car enough to get it under control. By > turning away from the corner you are reducing the drag not increasing it as > you are when you counter-steer or turn into the slide. You can also do this > by stabbing the brakes and locking up the fronts, however if you lock up all > four it also brings in the inertia of the sliding rear of the car and you > may slowly continue to rotate. > > Hope this makes sense > > Shane

Ok, so what you are saying is if you are loose on a oval and about to spin you turn left sharper to make the front wash out instead of counter steering? If this is what you are trying to say then can you point me to a book, driving instructor or some kind of literature where it say this works and to do it? I was just reading the book "Speed Secrets" pg.84 and in it James Weaver said that when he has lost it and is going to spin he does what I think you are saying by tightening the turn, not counter steering, but he is not doing it to save the car but is doing it to spin faster. I could see it on a oval if the car is at a yaw angle of over 90 degrees and spinning and then cranking the wheel full left as you might be able to pull the front end back out, that is if you have enough track to do it but would most likely back your car into the wall. What has more resistance/drag, a rolling tire or a sliding tire? Not too sure about the brake thing either. The way I see it is if the car is loose and starting to spin it is because there is not enough weight on the rear tires so when you hit the brakes you will transfer even more weight to the front wheels and make the rear lighter plus the engine braking effect, you will make matters worst. Once again I have never seen a Cup car about to spin and the driver lock up his brakes and watch his front end wash out and he makes a save with out even leaving his lane and keeps on cruising like nothing happened, but you do in N4. If it worked we would see it every weekend. I doubt they are running 100% front bias either. If you can find a mpeg of a driver doing this send it to me. That is me done for this thread. If someone can find the video's of Mika and someone in WC starting to spin and then locking his front brakes and having the front end wash out with out him leaving his lane and continuing like nothing happened, send them to me. -- Solo1 C-Modified (CASC-OR/BARC) http://www.barc-oc.com http://www.casc.on.ca

Alan Orton wrote: > > That is me done for this thread. If someone can find the video's of Mika > and someone in WC starting to spin and then locking his front brakes and > having the front end wash out with out him leaving his lane and > continuing like nothing happened, send them to me. Didn't JV do something like this at the last Canadian GP? I didn't see the footage as I was at the race, but I remember reading something along those lines a few days later. It was even discussed in RAS IIRC.

Firstly, apologies for posting a binary here, but it is very small, less than half the size of this thread and I know that many readers don't have access to the binaries group. I've been reading this thread with interest, without any examples I wasn't sure exactly what was being discussed. Certainly I do use a form of counter steering when I know that opp lock will not pull me out of a slide. The attachment is a replay sample from GPL. I am in an FD Ferrari at Mexico in the dreaded T1. Make sure you look at the clip from TV1 and TV2 also to get an idea of the degree of slide. I'm sure that had I kept opp lock I would have spun. Comments Welcome. Maxx On Sat, 23 Dec 2000 22:25:43 -0600, "Ronnie Bigwhip" <[email hidden]> wrote: >You guys noticed that when your driving that if you steer harder into the wrong direction when the rear kicks out that you can save it? >Say the rear kicks right, if you steer harder to the left you can save the car as oppose4d to steering into the spin......that cant possibly be correct could it??????????????

Alan, I think both events are possible and everybody here is actually right, depending on the car. I think I can prove you're correct mathematically, as well as prove the others are right too. Here goes: We've got two sides to this issue. 1. Steering into a spin won't work, because the increased drag from unusually high slip angles will transfer so much weight to the front of the car that the rears will tend spin out even further. 2. (My original argument). Since the slip angle went past its optimum slip angle and the direction of force caused the side component of the force to decrease rapidly after a point, the front end will lose traction and the car will tend to straighten out. In your experience, Alan, the first argument is what happens. It just dawned on me that the (steady state) front weight transfer is dependent solely on wheelbase and center of gravity height. What if the center of gravity height was very, very low, or the wheelbase was very long? Is there a point where it would become negligable and argument two would be correct? I think so. For example. Let's imagine a car (sorry about the US units here) with a 10 foot wheelbase, and a 2 foot center of gravity height, travelling at a constant forward speed through a corner. I'm looking at a graph in Milliken's "Race Car Vehicle Dynamics" for a stock car tire here. Of course, my numbers won't be exact, but I'll do my best here :0) Let's assume this car weighs 3600 lbs, and 1/2 of it is on the front end, with identical tires all the around. The front tires are turned at some unknown angle, but are operating at the peak: 6 degrees, making 1200 lbs of force perpendicular to the tire's direction. Cosine of 6 degrees times 1200 lbs = 1193 lbs of true sideforce times 2 tires = 2386 lbs of true sideforce that will torque (twist) the car around the yaw axis. Sine of 6 degrees times 1200 lbs = 125 lbs of drag times 2 tires = 250 lbs total front end induced drag Causes an acceleration of .07g .07 * (3600 lbs * 2 feet / 10 feet) = 50.4 50.4 lbs of front weight transfer. We'll assume we've got exactly enough throttle to keep our (.07g) acceleration, and therefore weight transfer, at 0, since we're driving through a corner at constant speed. The car is balanced perfectly, with the rear tires doing their thing to keep us right at the limit of traction at the rear. We're interested in weight transfer beyond this 50.4 lbs that is cancelled by the rear tire thrust, if my thinking is correct (I've been programming all night, so please excuse me if I make some horrendous mistake here!!) . If we crank the steering now to let the slip angle hit 30 degrees, and assume the tire makes the same amount of force (no loss after the peak, so that is no longer a factor to argue about) here's what happens: We've still got 1200 lbs of force at the front end, but now it's at a 30 degrees angle to the body. Cosine of 30 degrees times 1200 lbs = 1039 lbs of true sideforce times 2 tires = 2078 lbs of true sideforce torquing the car. Sine of 30 degrees times 1200 lbs = 600 lbs of drag times 2 tires = 1200 lbs total front end induced drag Causes an acceleration of .33g. We had enough force at the rear tires to generate .07g before this, so we'll subtract that to get our true deceleration of .26g. This gives us: .26 * (3600 lbs * 2 feet / 10 feet) = 187 lbs of weight transfer to the front end. Now we've got 93.6 lbs of additional load on each of the front tires. So now they're generating about 1300 lbs of force each. The rear tires lose 93.6 lbs (187/2), and they're generating about 1100 lbs each (2200 total), almost all of it is sideforce. Before, the true sideforces were equal. Now there's: Cosine of 30 degrees times 1300 lbs = 1125 lbs of true sideforce times 2 tires = 2250 lbs of true sideforce torquing the car. The rear now makes 2200 lbs total, compared to 2250 at the front end. ****The car starts to spin even harder as you said it does.**** This isn't really the final answer, but you hopefully you get the idea so far. **What happens if we drop the center of gravity height down to one foot?** I won't type it all down, but by cranking through these equations again, we end up with the rear end making about 2500 lbs, compared to about 2150 at the front after you crank the front wheels to a 30 degree slip angle. ****In this case, steering with the spin caused it to straighten out**** The same thing would happen if we lengthened the wheelbase enough. Argument one loses out and argument two takes over. Like I said, it's been a long night, so I may be missing something, but I think this is explains how both sides are right in different situations. In the future, I won't be surprised to hear this debate continue, as folks who drive short wheelbase or high center of gravity cars with tires that don't have a very peaky slip angle vs. lateral force curve will find Alan Orton's experiences to be correct, while others who drive very low, long cars, may argue. GPL cars probably fall into the second category, possibly even Nascars, but I really don't know for sure! Todd Wasson --- Performance Simulations Drag Racing and Top Speed Prediction Software http://PerformanceSimulations.Com

This still doesn't explain why you can crank the wheel tighter in GPL/N4 and you save it but when in the same position opposite lock will spin you. I'm sure there is less drag with a rolling tire compared to a sliding one pointed in the wrong direction. I think it would be tough to find the truth with a few equations. It is a dynamic problem with many variables. All 4 tires would be generating a constant changing and different turning force due to many variables. Such as aero dynamics, camber changes, changing cg/roll centers, weight shifts/momentum and tire temps and pressure. I don't deny the fact you will loose front end grip with high slip angles. Enough to catch a run away rear end? I'm still not convinced. If you read this, Rich. I tried emailing you but it wouldn't go through. J. Todd Wasson wrote:

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> > Alan, > > I think both events are possible and everybody here is actually right, > depending on the car. I think I can prove you're correct mathematically, as > well as prove the others are right too. Here goes: > > We've got two sides to this issue. > > 1. Steering into a spin won't work, because the increased drag from unusually > high slip angles will transfer so much weight to the front of the car that the > rears will tend spin out even further. > > 2. (My original argument). Since the slip angle went past its optimum slip > angle and the direction of force caused the side component of the force to > decrease rapidly after a point, the front end will lose traction and the car > will tend to straighten out. > > In your experience, Alan, the first argument is what happens. It just dawned > on me that the (steady state) front weight transfer is dependent solely on > wheelbase and center of gravity height. What if the center of gravity height > was very, very low, or the wheelbase was very long? Is there a point where it > would become negligable and argument two would be correct? > > I think so. > > For example. Let's imagine a car (sorry about the US units here) with a 10 > foot wheelbase, and a 2 foot center of gravity height, travelling at a constant > forward speed through a corner. I'm looking at a graph in Milliken's "Race Car > Vehicle Dynamics" for a stock car tire here. Of course, my numbers won't be > exact, but I'll do my best here :0) Let's assume this car weighs 3600 lbs, and > 1/2 of it is on the front end, with identical tires all the around. > > The front tires are turned at some unknown angle, but are operating at the > peak: 6 degrees, making 1200 lbs of force perpendicular to the tire's > direction. > > Cosine of 6 degrees times 1200 lbs = 1193 lbs of true sideforce times 2 tires = > 2386 lbs of true sideforce that will torque (twist) the car around the yaw > axis. > > Sine of 6 degrees times 1200 lbs = 125 lbs of drag times 2 tires = 250 lbs > total front end induced drag > > Causes an acceleration of .07g > > .07 * (3600 lbs * 2 feet / 10 feet) = 50.4 > > 50.4 lbs of front weight transfer. We'll assume we've got exactly enough > throttle to keep our (.07g) acceleration, and therefore weight transfer, at 0, > since we're driving through a corner at constant speed. The car is balanced > perfectly, with the rear tires doing their thing to keep us right at the limit > of traction at the rear. > > We're interested in weight transfer beyond this 50.4 lbs that is cancelled by > the rear tire thrust, if my thinking is correct (I've been programming all > night, so please excuse me if I make some horrendous mistake here!!) . If we > crank the steering now to let the slip angle hit 30 degrees, and assume the > tire makes the same amount of force (no loss after the peak, so that is no > longer a factor to argue about) here's what happens: > > We've still got 1200 lbs of force at the front end, but now it's at a 30 > degrees angle to the body. > > Cosine of 30 degrees times 1200 lbs = 1039 lbs of true sideforce times 2 tires > = 2078 lbs of true sideforce torquing the car. > > Sine of 30 degrees times 1200 lbs = 600 lbs of drag times 2 tires = 1200 lbs > total front end induced drag > > Causes an acceleration of .33g. We had enough force at the rear tires to > generate .07g before this, so we'll subtract that to get our true deceleration > of .26g. > > This gives us: > .26 * (3600 lbs * 2 feet / 10 feet) = 187 lbs of weight transfer to the front > end. > > Now we've got 93.6 lbs of additional load on each of the front tires. So now > they're generating about 1300 lbs of force each. The rear tires lose 93.6 lbs > (187/2), and they're generating about 1100 lbs each (2200 total), almost all of > it is sideforce. > > Before, the true sideforces were equal. Now there's: > Cosine of 30 degrees times 1300 lbs = 1125 lbs of true sideforce times 2 tires > = 2250 lbs of true sideforce torquing the car. > > The rear now makes 2200 lbs total, compared to 2250 at the front end. > ****The car starts to spin even harder as you said it does.**** This isn't > really the final answer, but you hopefully you get the idea so far. > > **What happens if we drop the center of gravity height down to one foot?** > > I won't type it all down, but by cranking through these equations again, we > end up with the rear end making about 2500 lbs, compared to about 2150 at the > front after you crank the front wheels to a 30 degree slip angle. ****In this > case, steering with the spin caused it to straighten out**** > > The same thing would happen if we lengthened the wheelbase enough. Argument > one loses out and argument two takes over. Like I said, it's been a long > night, so I may be missing something, but I think this is explains how both > sides are right in different situations. In the future, I won't be surprised > to hear this debate continue, as folks who drive short wheelbase or high center > of gravity cars with tires that don't have a very peaky slip angle vs. lateral > force curve will find Alan Orton's experiences to be correct, while others who > drive very low, long cars, may argue. GPL cars probably fall into the second > category, possibly even Nascars, but I really don't know for sure! > > Todd Wasson > --- > Performance Simulations > Drag Racing and Top Speed Prediction > Software > http://PerformanceSimulations.Com

-- Solo1 C-Modified (CASC-OR/BARC) 76 Trans-Am 600+hp http://www.barc-oc.com http://www.casc.on.ca

Alan Orton wrote: > > This still doesn't explain why you can crank the wheel tighter in GPL/N4 > and you save it but when in the same position opposite lock will spin > you. I'm sure there is less drag with a rolling tire compared to a > sliding one pointed in the wrong direction. Because we run with too little lock apply any sort of opposite lock that would help ? I think someone said that al that is needed to get around a 1.5 mile 0val is 2 degrees of lock on the wheels or something, considering that most of us set the max lock so that we almost have the steering at full angle when going through the corners, it doesn't leave you with much room to apply opposite lock when the rear breaks loose Beers and cheers (uncle) Goy "Team Mirage" http://members.prestige.net/bttw/teammirage/ "The Pits" http://www.theuspits.com/ * Spam is for losers who can't get business any other way * "Spamkiller" http://www.spamkiller.com

>This still doesn't explain why you can crank the wheel tighter in GPL/N4 >and you save it but when in the same position opposite lock will spin >you. I'm sure there is less drag with a rolling tire compared to a >sliding one pointed in the wrong direction. What if the body of the car is yawed 20 degrees relative to the direction it is moving? Front wheels straight ahead--> Slip angle = 20 Front wheels turned into corner 20 degrees ---> Slip angle = 40 Front wheels counter-steered 10 degrees----> Slip angle = 10. If the front tires peak at 10 degrees, countersteering 10 degrees with this car would result in peak cornering force. What about the forward weight tranfer though? That's what messes up this approach to figuring it out. Forward weight transfer is dependent (in steady state conditions) solely on wheelbase and center of gravity height. The last post used two center of gravity heights to show that the forward weight transfer could be enough, as you said, to cause it to lose the rear end even more quickly, even after the optimum slip angle was passed by a long shot. However, if the center of gravity height was 0 (never going to happen, I know that), there would be 0 weight transfer, so it is no longer a factor. As the center of gravity height is gradually increased, the weight transfer is increased as well, and I think there is a point where your argument becomes correct, but I think it depends on the particular car. A go-kart I raced indoors (lots of fun!) exhibited exactly this behavior. Once it slid, counter-steering A LITTLE often caused it to spin faster. Counter-steering just the right amount corrected the slide, while steering into the spin also corrected the slide. Perhaps this was because of the very low center of gravity height to wheelbase ratio. In full size sedans, such as your Trans-Am, the effect is quite different as you've noticed. My point is that BOTH situations are probably possible. I'd imagine a GPL or Formula car might have a low enough center of gravity height in relation to the wheelbase where it might handle more like the go-kart did, where a Nascar MIGHT behave more as your TransAm does. >I think it would be tough to find the truth with a few equations. It is >a dynamic problem with many variables. All 4 tires would be generating a >constant changing and different turning force due to many variables. >Such as aero dynamics, camber changes, changing cg/roll centers, weight >shifts/momentum and tire temps and pressure. Absolutely right. There are a lot of variables. However, in the last post, I assumed aerodynamics had no effect. I was trying to illustrate the impact the center of gravity height to wheelbase ratio had. Just add any aerodynamic downforce effects into those equations and try it again. I was assuming there were no camber changes, as these could tilt the results in EITHER direction, depending on the suspension geometry I suppose. You can make wheels camber about any way you want them to if you've got the freedom to design your own suspension. As for changing center of gravity position, it's usually small enough to be negligable in race cars that exhibit only 3 degrees or so of body roll, if that much. The weight shifts were the primary focus of the last post. I was attempting to show that wheelbase and center of gravity height are probably the main factors in determining which way a car will tend to handle in the conditions we're talking about. As for tire temps and pressure, I was assuming they were constant all the way around the car. Indeed, you're correct here, I think by changing these you'd have an even greater ability to make the car handle EITHER way, but only if the center of gravity to wheelbase ratio was within about the right range. Again, lowering the center of gravity height or increasing the wheelbase causes less fore/aft weight transfer, and the car should tend to follow people's descriptions of GPL driving more, in regard to steering into a spin to correct a slide. >I don't deny the fact you will loose front end grip with high slip >angles. Enough to catch a run away rear end? I'm still not convinced. In probably won't happen in your Trans-Am or other cars with a similar wheelbase to center of gravity height ratio. It seemed to happen in the go-kart I took out for a few laps though. My point is, I think both events are possible, and to discover this, focus efforts on wheelbase to center of gravity height ratio. Just my thoughts! :0) Todd Wasson --- Performance Simulations Drag Racing and Top Speed Prediction Software http://PerformanceSimulations.Com

in todays Murry and Martin F1 special (which i taped), theres footage of the man JV catching a slide at silverstone by countersteering late (which doesnt work), so he kinda releases the wheel back to centre and slams on front brakes, bringing the front back around. a la gpl and n4 pez Ronnie Bigwhip <[email hidden]> wrote in message news:utiMuDWbAHA.270@cpmsnbbsa09... You guys noticed that when your driving that if you steer harder into the wrong direction when the rear kicks out that you can save it? Say the rear kicks right, if you steer harder to the left you can save the car as oppose4d to steering into the spin......that cant possibly be correct could it??????????????