Forza Motorsport 3

[cpp214]

I've seen a lot of discussion in this thread about the Forza 3 demo's "roll over" physics.
Many people are claiming that the roll over physics are not realistic. Simply based on the YouTube video of the Lancer rolling over,

I'm inclined to think that the roll over physics model in Forza 3 looks pretty credible.

As Eric pointed out above, cars have roll over accidents on a daily basis.
And not all of them are SUV's (although vehicles with a higher center of gravity are more prone to roll overs than other vehicles). One thing we can't see from that video is how fast the Lancer Evo is travelling. However, due to the centripetal loading placed on vehicles when approaching corners at a high rate of speed, it's quite possible for cars to roll over in much the same way as the cars in the Forza 3 demo roll over.

Here's an article detailing the physics involved in vehicle rollovers:

arts.bev.net/roperldavid
/rollovers.pdf

While much of this article involves some fairly detailed physics calculations--which might as well be written in Mandarin Chinese, because I can't understand them--there are some pretty simple, straightforward concepts that the layperson can take away from it. In particular, I noticed the following:

"In a real situation a vehicle is usually moving when it rolls over, not standing still on a slope.
We consider two types of idealized moving rollover situations:

1) A vehicle is moving (sliding) sideways and the wheels strike a solid obstacle
that provides a pivot point for a possible rollover.
Rollover occurs when the ensuing rotation causes the force of gravity vector to pass through the pivot point.

2) A vehicle is moving, without slipping, around a circular curve at a constant
speed high enough to just cause rollover. Rollover occurs when the force of gravity vector passes through the pivot point. It should be emphasized that the effects of suspension movement, tire movement or electronic/mechanical stability control may be very important in the rollover tendency for a vehicle. Suspension and tire movements would likely increase the tendency for rollovers, while electronic/mechanical stability control is designed to make it less likely that a vehicle would get in a situation where rollovers occur."

The "pivot point" in the case of the Lancer Evo in the YouTube video could easily be the transition from tarmac to grass--which is hardly ever a smooth one in real life, and is almost always marked by a "drop off." Usually such a transition is marked by at least a few inches of drop-off from the asphalt/tarmac to the grass, and the sudden loss of traction incurred by going from a grippy surface (asphalt) to a much less "grippy" surface (grass) can't help the overall stability of the car. At the least, I would expect that if the car was already travelling too fast heading into the corner, veering sharply into the grass would only worsen the situation and make a rollover more likely. Or, the roll over could have also been caused by explanation 2) above: "A vehicle is moving, without slipping, around a circular curve at a constant speed high enough to just cause rollover." Also, we don't know if the Evo was using stability aids such as ASM or TCS. If no driving aids were enabled, it would make the possibility of roll over more likely. I'm inclined to believe the rollover in the video was caused by explanation 2), coupled with the sudden loss of traction caused by transitioning from the ashpalt to grass.

In any event, roll overs such as those I've seen from the Forza 3 demo seem fairly realistic to me. It appears that the car is travelling at a fairly high rate of speed, while at the same time trying to make a fairly sharp turn. I think it offers a pretty accurate representation of what could happen if a driver attempted such a reckless maneuver in the real world.

But, as you can probably guess, I didn't major in physics, so I may be way off base with these guesses.
I'm just trying to point out how such a roll over could be plausible.

 

[DrTrouserPlank]

In short I thought it was quite believable based on a simple analysis of the physics going on at the time.

In addition though, it seems unlikely that there would be two physics engines at work in the game; one that is in operation when the cars are on track doing what they should be doing, and another that is used to sensationalise crashes, rolls and flips, which leads me to believe that there were fair conditions for the car to roll.

Must have looked quite cool from cockpit cam of the other car as this evo just rolled in front of it across the track XD

 

[Scaff]

I've seen a lot of discussion in this thread about the Forza 3 demo's "roll over" physics.
Many people are claiming that the roll over physics are not realistic. Simply based on the YouTube video of the Lancer rolling over,


I'm inclined to think that the roll over physics model in Forza 3 looks pretty credible.

I'm inclined to disagree.

As Eric pointed out above, cars have roll over accidents on a daily basis.
And not all of them are SUV's (although vehicles with a higher center of gravity are more prone to roll overs than other vehicles). One thing we can't see from that video is how fast the Lancer Evo is travelling. However, due to the centripetal loading placed on vehicles when approaching corners at a high rate of speed, it's quite possible for cars to roll over in much the same way as the cars in the Forza 3 demo roll over.

As I'm going to point out you have extracted a bit of a false premise from the source material you have quote, which quite clealry indicates that by far the greatest risk of roll-over comes from vehicles with a high COG and narrow track.

Vehicles with a wide track and a low COG (such as an Evo X) are at a significantly lower risk of roll-over, to a degree that given the visual evidence shown in the video I consider it quite unlikley to be caused by cornering forces alone.

Here's an article detailing the physics involved in vehicle rollovers:

arts.bev.net/roperldavid
/rollovers.pdf

While much of this article involves some fairly detailed physics calculations--which might as well be written in Mandarin Chinese, because I can't understand them--there are some pretty simple, straightforward concepts that the layperson can take away from it.

I do understand a great deal of what is being discussed in that piece, and one of the problems with taking a laypersons view of it, is that the view can be inacurate.

In particular, I noticed the following:

"In a real situation a vehicle is usually moving when it rolls over, not standing still on a slope.
We consider two types of idealized moving rollover situations:

1) A vehicle is moving (sliding) sideways and the wheels strike a solid obstacle
that provides a pivot point for a possible rollover.
Rollover occurs when the ensuing rotation causes the force of gravity vector to pass through the pivot point.

This situation concerns a vehicle hitting a low object (such as a vertical edged curb), at speed and traveling sideways.

Now while such a situation is a common factor in roll-overs on the public roads, I think we can discount it as a factor on what is meant to be a purpose built track. Even circuits converted from public roads remove or cover objects such as these to remove this specific risk.

2) A vehicle is moving, without slipping, around a circular curve at a constant
speed high enough to just cause rollover. Rollover occurs when the force of gravity vector passes through the pivot point. It should be emphasized that the effects of suspension movement, tire movement or electronic/mechanical stability control may be very important in the rollover tendency for a vehicle. Suspension and tire movements would likely increase the tendency for rollovers, while electronic/mechanical stability control is designed to make it less likely that a vehicle would get in a situation where rollovers occur."

While this one does stand a theoretical chance of occuring, the physics detailed in the article do quite clearly show that the speeds the vehicle would need to be travelling would make it very unlikely. Again the piece majors on how this is a common issue with SUV style vehicles due to the high COG and narrow track (for the height) making them inherently unstable in these situations.

The "pivot point" in the case of the Lancer Evo in the YouTube video could easily be the transition from tarmac to grass--which is hardly ever a smooth one in real life, and is almost always marked by a "drop off." Usually such a transition is marked by at least a few inches of drop-off from the asphalt/tarmac to the grass, and the sudden loss of traction incurred by going from a grippy surface (asphalt) to a much less "grippy" surface (grass) can't help the overall stability of the car. At the least, I would expect that if the car was already travelling too fast heading into the corner, veering sharply into the grass would only worsen the situation and make a rollover more likely. Or, the roll over could have also been caused by explanation 2) above: "A vehicle is moving, without slipping, around a circular curve at a constant speed high enough to just cause rollover." Also, we don't know if the Evo was using stability aids such as ASM or TCS. If no driving aids were enabled, it would make the possibility of roll over more likely. I'm inclined to believe the rollover in the video was caused by explanation 2), coupled with the sudden loss of traction caused by transitioning from the ashpalt to grass.

No and no to both of your points here.

First a drop off would not act in the same manner as a raised pivot point at all, so the basic assumption in your first point is flawed to begin with.

Secondly the transition from tarmac to grass would see the leading tyres loose a signification amount of traction, that would reduce grip significantly, removing some of the load transfered to the front. In a nutshell it would actually reduce the change of a roll-over occuring (based on just these two factors).

In fact looking at just the two factors you have focused on, its actually more likley that a car would roll over if it came off the grass at speed and hit the tarmac, with the higher height of the tarmac (your example not mine) acting as a pivot point and the greater traction from the tarmac providing more grip and an even greater transfer of load to the leading tyres (and an even more unbalanced car as a result.

The main reason a car will roll when it hits grass is down, in the main, to the tyre seperating from the rim (which could be caused by extreme lateral loading or damage caused from an impact) and the rim digging into the grass.

However to be quite honest about it, this is still an unlikley event in its own right, outside of very lightweight cars (which the Evo X is not).

In any event, roll overs such as those I've seen from the Forza 3 demo seem fairly realistic to me. It appears that the car is travelling at a fairly high rate of speed, while at the same time trying to make a fairly sharp turn. I think it offers a pretty accurate representation of what could happen if a driver attempted such a reckless maneuver in the real world.

But, as you can probably guess, I didn't major in physics, so I may be way off base with these guesses.
I'm just trying to point out how such a roll over could be plausible.

Sorry but I just can't agree with you on this at all, and I'm afraid your source material doesn't help. Nor does it help that the piece itself 'omits' a rather important factor (which it at least acknowledges its omits) in the section on roll-over from corning speed alone, and that's covered in this quote....

(Assume that the vehicle does not slip sideways.)

...which kind of throws a spanner in the works to a large degree. As the speeds required for roll-over to occur before slip does is again a trait found almost only in those vehicles with a high COG and a narrow track (in relation to the COG).


That aside it is however a quite interesting piece, so thanks for the link, its now joined my very extensive collection.


Regards

Scaff

 

[Chronos]

Originally Posted by Ding:
I know that it swaps in higher poly car models

chespace: Wrong.

Originally Posted by Ding:
There's nothing wrong or sneaky about that, but I'd hate to see a backlash (Here? Never!) when the in-game experience doesn't quite match the prettiness shown in these shots.

chespace: Go watch some in-game videos. Plenty of them around.


Originally Posted by Ultimo hombre:
How did the ingame graphics compare to the photo mode shots we normally get?

Was cockpit mode still 30fps?

Great impressions btw. Nice to see the handling improved even more.

chespace: The in-game graphics look the same as photomode. When gameplay footage gets released as the press receive builds, it'll be pretty obvious.

Also, don't worry about framerate. FM3 is a 60fps game.

The posts on gaf are strange. Why bother saying this stuff when the demo a month before shows the opposite.

I never believed that FM3 was doing 10x more polys on the cars ingame or replay. Before the videos many were quick to say FM3 has 1million polys per car. Thats total dream land. FM3 maybe pushing around 500k in the menu screens only but that wouldn't of sounded good at E3. "We're pushing 10x the polys in the menu screens folks"

Games do mislead or show bullshots for presentation but not a lot is said by the devs. The GAF posts are like some damage control reaction or something. How is he allowed to? Seems very unprofessional.

 

[oqvist]

This thread is getting surreal? Why is there quites with some chechou some chesquirrel and such and when you go back you see no such posts?

what is GAF I feel like I was born yesterday lol

 

[UnoMOTO]

Friction in this case can overcome a low center of gravity. Yes...no...?!

 

[DrTrouserPlank]

This thread is getting surreal? Why is there quites with some chechou some chesquirrel and such and when you go back you see no such posts?

what is GAF I feel like I was born yesterday lol

Those are quotes (I assume, I'm not going check back through all 73 pages of it and counting) from the NeoGAF thread that is tantamount to GT5 vs Forza3.

It's a haven for fanboys of both consoles to duke it out to the death, amusing as it is, the possibility of anything approaching sensible debate is unlikely.

Link to the train-wreck as it grows:-

http://www.neogaf.com/forum/showthread.php?t=375000&page=73

 

[otago]

Yes, even on public roads under normal driving conditions.

Buy some decent car

 

[Chronos]

This thread is getting surreal? Why is there quites with some chechou some chesquirrel and such and when you go back you see no such posts?

what is GAF I feel like I was born yesterday lol

Che is T10 community manager I believe. Gaf is neogaf, a forum for devs, dev groupies, and fanboys it seems. Around 2 months ago, FM3 news came from gaf with che posting new info and screens instead of the official site. A shame as most of the pages are spam. Why not share the info with real fans first instead of that lot on neogaf?

The posts are on the site.

At the end of the page.
http://www.neogaf.com/forum/showthread.php?t=363608&page=49

http://www.neogaf.com/forum/showpost.php?p=16902781&postcount=4169

 

[Famine]

Buy some decent car

What a completely unpredictable response that was

You ignored everything I wrote and went straight for a ridiculous answer based on no knowledge at all. You'll note I didn't refer to my own car or any of the cars I've driven in the last fifteen years. And why? Because it applies to all bodies in motion on Earth. It has nothing at all to do with the car you're in at the time - it could be a Veyron or a VAZ.


Go do the test I suggested. If you really personally cannot detect any weight transfer I'd suggest you have an inner ear malfunction.

 

[MagpieRacer]

Friction in this case can overcome a low center of gravity. Yes...no...?!

Arent they doing 190mph in NASCAR though? Will be interesting to see what the physics experts have to say.

Adding to this:

I am not sure what car this is but it doesnt appear to be a 4x4 or high COG car, goes sideways and rolls, at relatively low speed, I think grass is the factor.

 

[Scaff]

Friction in this case can overcome a low center of gravity. Yes...no...?!

Not friction, but speed, the roll-over occured in that case when the car was hitting around 195mph. Combine that with the rather 'wonky' suspension set-up you have on NASCAR as you have a quite different situtation to the Evo X one.

Here's and Evo in the kind of situation described above failing to roll-over.




Regards

Scaff

 

[MagpieRacer]

Not friction, but speed, the roll-over occured in that case when the car was hitting around 195mph. Combine that with the rather 'wonky' suspension set-up you have on NASCAR as you have a quite different situtation to the Evo X one.

Here's and Evo in the kind of situation described above failing to roll-over.




Regards

Scaff

The situation in the FM3 video, the car rolls on grass, I am willing to bet doing that on tarmac in FM3 the car wont roll, I would like to see a vid of a Lancer spinning like that but on grass.

 

[otago]

Because it applies to all bodies in motion on Earth.

Theoretically yes. On practice even latest Eclipse, which I drove before, has zero body roll at any public road driving conditions. It has of course, but nothing you can feel, even if you really try to feel something.

And this car has pretty comfortable suspension for sporty coupe. Very good balance between sport and comfort ride. Though steering feels kind of artificial in my opinion.

 

[Famine]

Theoretically yes. On practice even latest Eclipse, which I drove before, has zero body roll at any public road driving conditions. It has of course, but nothing you can feel, even if you really try to feel something.

And this car has pretty comfortable suspension for sporty coupe. Very good balance between sport and comfort ride. Though steering feels kind of artificial in my opinion.

You're not paying attention. Weight transfer isn't caused by body roll. Even with zero body roll on solid dampers you'd be able to feel weight transfer.

Body roll is a symptom of weight transfer. It's not a cause of it. Even if it isn't there, weight transfer still occurs - it has to, because the car isn't moving at a constant, never-changing speed.


Try the test I told you about previously. Plastic cup full of water on your centre console, then do your normal daily drive. What happens is as a result of weight transfer.

That said, if my word isn't good enough, based on some notion you have about my cars (incidentally, Eclipse? Too slow), ask Scaff. He's been working in the automotive industry longer than I've been driving.

 

[UnoMOTO]

Not friction, but speed, the roll-over occured in that case when the car was hitting around 195mph.

I don't agree. On a low friction surface like ice, the car would not have rolled, even at 195. The right amount of rubber meeting the road will cause a roll over at a variety of speeds.

 

[Dave A]

The situation in the FM3 video, the car rolls on grass, I am willing to bet doing that on tarmac in FM3 the car wont roll, I would like to see a vid of a Lancer spinning like that but on grass.

A car would be more likely to roll on tarmac than grass, tarmac is a grippier surface. Grass is slick and will cause a car to slide much more than it can on tarmac. The most likely way to flip a car with a low COG on a smooth grass surface would be if a structurally fixed part of the car dug in which would usually be the rims if the car burst a tyre. It could be that a car is badly damamged and a collapsed suspension causes part of the mounts to hit the ground and dig in. It would take more than a few stones and divets in the grass to flip a sportscar like the Exo X. There has to be either a factor in that Forza flip we couldn't see, or the game simply models the flips wrong.

Actually in my personal experience of the Forza demo, the cars did tend to leave the ground and pitch very easilly when you hit something. I've seen collisions where a car has rolled tail over nose in that demo for hitting a spinning car. In my opinion it's exaggerated, it's a good feature and better than not being able to roll at all, but they've exaggerated it under certain conditions.


EDIT: I beleive that NASCAR flip is a combination of the speed, surface and the cars odd setup which goes from using different ride heights and suspension on the left as the right to using different tyres altogether on the left as the right. The left side is much grippier and at the same time softer than the cars right side on an oval setup. The car rolls when it spins and the weight is shifted to it's softer and grippier left side. The surface had a part to play, but if that car span counter clockwise it would probably not have flipped. I don't think you can use a NASCAR running an oval setup to backup how a road car (or even another race car) might behaive under certain circumstances.

 

[Scaff]

The situation in the FM3 video, the car rolls on grass, I am willing to bet doing that on tarmac in FM3 the car wont roll, I would like to see a vid of a Lancer spinning like that but on grass.

A tyre on grass has a much lower co-efficent of friction that one on tarmac does, so as you are going to loose grip more easily you are less likely to roll than on tarmac.

A roll-over occurs on grass almost always due to two factors, either a part of the car (that will not easily snap off) digs in and acts as a pivot point (see the first factor in the .pdf above) or the grass is sufficently bumpy enough (and the car light enough) to totally unsettle it.


However here you go, an Evo at the 'ring. Tarmac to grass spin (twice by the looks of it) and no roll-over.

Yes cars can and do roll over, does that make the roll-over of the Evo in the FM3 vid realistic to my eyes and experience, nope sorry but it doesn't.

I don't agree. On a low friction surface like ice, the car would not have rolled, even at 195. The right amount of rubber meeting the road will cause a roll over at a variety of speeds.

My bad, didn't quite get what you were driving at originally (that will teach me to post when I'm trying to eat at the same time), and you are quite right. The co-ef of friction (slicks with a high grip track surface) combined with the speed, in this example, mean that the tyres arn't slipping enough to stop the COG of the car reaching a point that will roll it.

However I'm sure you would acknowledge that's quite a different set of circumstances to the Evo.


Scaff

 

[UnoMOTO]

However I'm sure you would acknowledge that's quite a different set of circumstances to the Evo.

It does appear to just “float” off the ground and roll over. As if it has a higher COG then it should.

At least in this conversation I hope many have learned the complexity of physics in rolling over a car. As Dave said, many things apply in any given condition.

 

[Tenacious D]

The one thing that still kinda bothers me is how you really don't see that much body roll or weight transfer visually. For example, race the mini, and in the replay, change the car camera to the challenger up in front. Watch at how hard the car brakes and turns, but the car does not pitch and roll like how a 4000 lb (im guessing) car with a soft suspension setup should. You see the wheels bobbing up and down, but you do no the see that chassis lean and dip under hard braking and turning. It's weird. Im just talking visually, you feel the car do these things, but you don't see it the way you do in GT. Is it just me? What do you think.

Forza has always had problems in this regard. Even old muscle cars with soft suspensions which should roll like jello are rock solid and level in every game.

 

[Kryz11]

One big question about FM3 that was missing in FM2 in physics.. In GT5Prologue, when you drive a Mid Engine car such as the Lotus or the F430 or Ford GT... when going on high speed curve or corner, if you lift throttle the cars behind will try to slide and you will fish tail, if you play GT5P, with a wheel , or not you know what I mean.. thats why in real life you have to always have gas pressed a little on those high speed corners at high speeds to keep the rear of car balanced...

Is it noticible in FM3 with MR or RR cars?
someone respond =)
FM2 never had it, and I hope they have it in FM3 now!!! man I cant wait for this game.. I cant wait !!!

HAHA I am buying another Fanatec wheel just for this (also Ps3 games) game!!! Yes I said another one



And Scaff very good point and video, I posted few pages ago the video of Prosche Tech Art Going super fast and car hit barriers, spins both on grass, asfolt, even over the bumps.. no spinning over..


I think the Turn10 guys made it bit easier so you THINK its realistic! Just like wtih FM2 gameplay, because its easy you think its more real.

 

[otago]

Body roll is a symptom of weight transfer. It's not a cause of it.

Graduated from University of Obvious?

I don't think you can find anybody here who really think that body roll is a cause of weight transfer.

(incidentally, Eclipse? Too slow), ask Scaff. He's been working in the automotive industry longer than I've been driving.

For drug races yes. In turns only suspension, wheelbase and stuff like this matter. Power is not a factor on twisted road, Elise 111R will most likely outperform Ferrari California on mountain roads.

ask Scaff. He's been working in the automotive industry longer than I've been driving.

I hardly believe in guy having on the table Milliken's "Race Car Vehicle Dynamics" and praising GT5P physics.

Just me probably

 

[Jay]

A tyre on grass has a much lower co-efficent of friction that one on tarmac does, so as you are going to loose grip more easily you are less likely to roll than on tarmac.

A roll-over occurs on grass almost always due to two factors, either a part of the car (that will not easily snap off) digs in and acts as a pivot point (see the first factor in the .pdf above) or the grass is sufficently bumpy enough (and the car light enough) to totally unsettle it.


However here you go, an Evo at the 'ring. Tarmac to grass spin (twice by the looks of it) and no roll-over.

Yes cars can and do roll over, does that make the roll-over of the Evo in the FM3 vid realistic to my eyes and experience, nope sorry but it doesn't.

Exactly, this is what I was getting at.

 

[Chronos]

Link to the train-wreck as it grows:-

http://www.neogaf.com/forum/showthread.php?t=375000&page=73

Familiar name there.

Also another one: RandomXTX on gaf.

Infamous GT5 Neogaf Microsoft Fanboy Poster Actually Works For Turn 10

http://www.thebitbag.com/2009/09/28...oft-fanboy-poster-actually-works-for-turn-10/

Some of the newer posters in the GT5 section wouldn't surprise me being the same.

Some vids from yesterday

Fan Favorites Walkthrough with the FM1 track. Now about 10 miles long and over hundred corners. Drift mode and drift scores.
http://www.gametrailers.com/video/tgs-09-forza-motorsport/56932

New Modes Walkthrough
http://www.gametrailers.com/video/tgs-09-forza-motorsport/56940

 

[cpp214]

I'm inclined to disagree.

As I'm going to point out you have extracted a bit of a false premise from the source material you have quote, which quite clealry indicates that by far the greatest risk of roll-over comes from vehicles with a high COG and narrow track.

I'm not sure how to interpret this remark. If you are implying that I intentionally tried to mislead people into adopting a particular interpretation of that source, then you are mistaken. The reason I provided a link to the article is so people could check it out for themselves and draw their own conclusions.

Vehicles with a wide track and a low COG (such as an Evo X) are at a significantly lower risk of roll-over, to a degree that given the visual evidence shown in the video I consider it quite unlikley to be caused by cornering forces alone.

No, it wasn't cornering forces alone, it was the sudden loss of traction that occured when the Evo ran off the tarmac and onto the grass as I surmised in my post. In fact, to back up this assertion, here is a link to a research article conducted by the UK’s Cooperative Crash Injury Study (CCIS) "...one of Europe’s largest car occupant injury causation studies." http://www-nrd.nhtsa.dot.gov/pdf/esv/esv21/09-0481.pdf

Among the findings in this study is the fact that "off-road soft surfaces such as grass or earth were the most frequent roll initiators." Even more frequent than loss of traction due to excessive speed while cornering, which I must admit suprised me a bit.

Secondly the transition from tarmac to grass would see the leading tyres loose a signification amount of traction, that would reduce grip significantly, removing some of the load transfered to the front. In a nutshell it would actually reduce the change of a roll-over occuring (based on just these two factors).

Apparently not, according to the government study I linked above.
In fact "The most common roll initiation influence was offroad
soft ground (grass or earth) applying force to both wheels (right or left)."
If anything, transitioning from pavement to grass increases the chance of a rollover.

In fact looking at just the two factors you have focused on, its actually more likley that a car would roll over if it came off the grass at speed and hit the tarmac, with the higher height of the tarmac (your example not mine) acting as a pivot point and the greater traction from the tarmac providing more grip and an even greater transfer of load to the leading tyres (and an even more unbalanced car as a result).

No, apparently it's more likely that going off-road onto grass will cause rollovers according to the data in the study listed above.

...which kind of throws a spanner in the works to a large degree. As the speeds required for roll-over to occur before slip does is again a trait found almost only in those vehicles with a high COG and a narrow track (in relation to the COG).

Evidently, wheel-slip and roll over aren't mutually exclusive events:

"A significant proportion of the cars were identified as
‘sliding’ laterally to some degree prior to the roll and
off-road soft surfaces such as grass or earth were the
most frequent roll initiators."

That aside it is however a quite interesting piece, so thanks for the link, its now joined my very extensive collection.

Regards

Scaff

Well, if you liked the previous link, I hope you like this one as well.
I think it makes a compelling argument that a roll over like the one we saw in the now-infamous YouTube video is quite possible.

My main points:

1) The transition from tarmac to grass can cause rollovers like the one in the Evo clip. In fact grass/earth are the most frequent causes of roll over incidents in the study above. And that study has a pretty large sample size--1,341 incidents of rollovers.

2) Just because it is more likely that a high COG SUV will rollover, that doesn't necessarily mean that a car such as the Lancer couldn't plausibly roll over as it does in the video. It was travelling at a what appears to be reasonably high speeds (although admittedly unknown), and it did what one should apparently do if they want to roll a vehicle over: make a sudden steering input onto grass or an earthy surface at high speeds...while cornering.

I hope I don't come across as argumentative, but I felt as though I should respond. When I saw the video, I thought it looked really innovative and realistic. I guess I'm just trying to defend that initial impression. I greatly respect your opinion on this matter, and I just happen to disagree. Your expertise in this field is unquestioned in my view. I'm just trying to argue for my position as well as I possibly can

(Trust me, I don't want to make a habit of getting into confrontations with Moderators)

 

[KSaiyu]

Graduated from University of Obvious?

I don't think you can find anybody here who really think that body roll is a cause of weight transfer.



For drug races yes. In turns only suspension, wheelbase and stuff like this matter. Power is not a factor on twisted road, Elise 111R will most likely outperform Ferrari California on mountain roads.



I hardly believe in guy having on the table Milliken's "Race Car Vehicle Dynamics" and praising GT5P physics.

Just me probably

Wow I take back my apology, surely this is just trolling 👎

 

[Zathra5_]

The evo flip does not look realistic. The car starts rolling almost at the same time it starts to go sideways. At that point the ground can not be producing much lateral force on the car tires. The angle is too small. Additionally there is no evidence that the tires catch on anything. this would be needed for it to flip on grass. The entire rollover is way to smooth. Nothing in the video suggests the grass suddenly imparting more force on the tires.

 

[otago]

Wow I take back my apology

No! You can't do this to me

 

[Eric.]

Give me 20 minutes and I'll be back to tell you everything that the telemetry says is going on when you roll an Evo X.

 

[otago]

Give me 20 minutes and I'll be back to tell you everything that the telemetry says is going on when you roll an Evo X.

Yeah, it would be interesting.

Definitely some physics bug, such rollovers on grass looks as far from reality as you can get. There are plenty of videos like this from demo