GT6 grass/dirt Physics Flaw

[Dodzzz]

I hate the grass since GT5, and until now in GT6, the grass is still flawed.

It's like it's designed to rotate any car which one of its rear tires touches it..
That logic pisses me off often.. when I push the car to it's limit, a little touching on a grass is inavoidable, and the result often catastrophic.. where in real life it shouldn't happen.

Here I have the video to prove that flaw..
I was time trialing a FWD Clio RS, then this happened (twice, and redoable)
Can you believe it? a powerslide in an FF? this proves that the grass is designed to rotate any car, regardless the drivetrain of the car, let alone the acceleration applied at that time.



here is also the screenshot from another angle where it just right before it slides
as you can see, the front (powered) wheel didn't even touched the grass area (in this case, dirt)
and one of the rear tire is also still in the tarmac.
logicly, my car shouldn't slide like that.

 

[subsist]

This has been an annoyance of mine since I started racing online. You put one wheel on the grass coming off a corner and you might as well just finish the race there because 9/10 the car will be put into a spin.

It has been somewhat better since the forced traction control is not applied as soon as you go off road now but still not perfect.

 

[VBR]

I don't think there's anything wrong here. Think about it; if you're exiting a corner, all the weight of the car is on the outside wheels, if they then touch the grass of course they're gonna lose traction, as grass has less traction than tarmac/asphalt! If the car is not turning & the outside wheels are not under load, then driving with 2 wheels on the grass will not spin you out. I think it's modeled very well, & is very much like real life. I guess some people simply don't understand loading & unloading the tyres whilst transitioning between different grip levels. Ever heard of a dirt bomb drift? If there wasn't less traction on the grass/dirt off track they'd be impossible to do in real life, but they're not. I rest my case.

 

[Imari]

If you put both left side wheels off, you'd expect to slide wide, no? Because you lose a huge amount of the grip that you have to push you around the corner.

Suddenly losing grip on one rear tyre is going to unbalance the car. Unless you're ready for it and compensate really fast, it's going to spin, every time. What you're doing is catchable, but you have to drive into the gravel pit to do it. The front wheels will not just pull the car straight.

What would you expect to happen if you were going around that corner in real life, and you had a blowout in that tyre? Think you'd make it round OK, or do you think you'd spin?

 

[Dodzzz]

Yeah I was ready for it so that's why I gently floor the gas in order to move the car forward exiting the dirt area, knowing my car I was driving is an FWD car, so I thought, no problem because my front tires was in the tarmac.

Sudden loss of one rear left tire in an FWD car should not produce a powerslide effect like that.

 

[DolHaus]

Yeah I was ready for it so that's why I gently floor the gas in order to move the car forward exiting the dirt area, knowing my car I was driving is an FWD car, so I thought, no problem because my front tires was in the tarmac.

Sudden loss of one rear left tire in an FWD car should not produce a powerslide effect like that.

In this circumstance is doesn't matter what drive train the car is, its not a power slide but an effect of weight transfer. When you corner any car the weight transfers from front inside wheel on entry to rear outside wheel on exit. If you put the rear wheel on the grass on exit then the tyre cannot resist the lateral weight transfer because of the reduced friction and slides until the weight centres again.
Not a bug, just a result of physics. If you watch some BTCC or ITCC (Touring Cars), most of these are front wheel drive and they often spin or go sideways because they put the rear wheel on the grass when exiting corners. Basically if there is nothing to oppose the lateral weight transfer, the rear of the car will travel in the direction of least resistance.
In a front wheel drive car you can usually save it by staying on the throttle and using the powered wheels to pull you out of the slide.

 

[GTP_CargoRatt]

As said by @VBR there is nothing wrong here and that is exactly how it would happen in real life. This isn't a flaw at all...you have all the weight transfer on that tire and when you lose grip like that, of course you are going to spin, unless of course you are quick enough to catch it. Nothing wrong here.

 

[Dodzzz]

How about this? this what should happen, (or at least in my case, I was expecting my rear left tire would only generate a lot of dirt smoke and that's it)


It should be just like that, no exaggerate spinning like in GT6.

I have searched for youtube for crashes and spin videos, and still having difficulties finding the perfect example in real world videos that ONLY one rear tire touch the grass/dirt could spin a whole car.. an FWD car to be exact.

If anyone could find one, please let me know!


add one more example:



In GT6, Vettel's race would pretty much end there.. but not in real life? and it was even a 700HP MR car

 

[DolHaus]

Your spin was 100% normal, this is not a physics glitch.

(theoretical numbers to illustrate point)
Lets simplify friction dynamics by saying you can exert 2000kg of force against it without braking traction when on tarmac and 200kg when on dirt/grass.
You are turning hard right and travelling forwards, this means that because of the way weight transfer works (always acts in the opposite direction to motion) the weight of the car is focused on the rear left tyre. Lets say you're exerting 2000kg of force on that rear wheel and the friction is what stops you from over-rotating (spinning) because it can resist with equal and opposite force.
As soon as that rear wheel touches a lower friction surface, in this case dirt, the forces applied cannot be resisted and so the weight will travel in the direction of least resistance. Traction is broken instantly and the car suddenly starts travelling in pretty much the opposite direction pivoting around the cars centre of gravity as the forces balance themselves out.

 

[DeltawingR18]

I like to use the grass to my advantage. Tap the grass with the back wheels, slide around the turn. Brands Hatch turn 3 is a good example.

 

[Lewis_Hamilton_]

In GT6, Vettel's race would pretty much end there.. but not in real life? and it was even a 700HP MR car

You can do that in GT6, it's about managing your throttle, brake and steering inputs carefully, you can't ask nearly as much from the tire that is losing traction. I can't view the clip but I'm assuming it's at Monza, there was very little load going on to the outside tire and not a lot of steering input was needed.

In all the years I've been watching motorsport, I think it's probably rarer to *not* see someone spin out like this at least once in a race.

Look at the entrance to Spoon Curve at Suzuka in Formula1 a year or 2 ago, there were several cars that came off in exactly the same spot by doing exactly the same thing, clipping the rear tire on to a tiny, tiny patch of grass just before the kurb. It ended with a miniture, expensive scrap yard against the outside barriers.

 

[Johnnypenso]

You can do that in GT6, it's about managing your throttle, brake and steering inputs carefully, you can't ask nearly as much from the tire that is losing traction. I can't view the clip but I'm assuming it's at Monza, there was very little load going on to the outside tire and not a lot of steering input was needed.

100%👍 The slide caught in the above video at Brands Hatch I've done many, many times in GT6. I tuned all my cars at least partially at that track and have had many offs just like that one. It's a question of balancing your steering input, and throttle mostly.

 

[bluecharger]

It might be perfectly normal in GT and it might be something you just have to guard against at all cost when playing, and I get that the incident shown in the OP is at a bit of an extreme force/direction angle thing, but it's still way too much vs. real life. It DOES matter what drivetrain configuration you have as to how much slippage one rear tire can encounter to affect the entire behavior of a car. A one-tire drop-off shouldn't throw the whole car in the example completely around.

 

[Lewis_Hamilton_]

A one-tire drop-off shouldn't throw the whole car in the example completely around.

Why not? That wheel has lost traction while the others haven't, therefore it's going to get swung around, just like if you were to break traction at the rear by pulling the handbrake.

One of the major accidents I was involved in (riding in the back, not driving) happened like the OP's video. As my mother swerved to miss a drunk driver pulling across the road directly in front of us, the rear tire with load on it dipped into the sand along the road edge, it span the car around 180 degrees even though my mum was counter steering, where the vehicle then hit the edge of the other side of the road and performed 3 flips. We were doing 70mph at the time in a front wheel drive car.

 

[Johnnypenso]

It might be perfectly normal in GT and it might be something you just have to guard against at all cost when playing, and I get that the incident shown in the OP is at a bit of an extreme force/direction angle thing, but it's still way too much vs. real life. It DOES matter what drivetrain configuration you have as to how much slippage one rear tire can encounter to affect the entire behavior of a car. A one-tire drop-off shouldn't throw the whole car in the example completely around.

70-80% of the rear cornering load goes from tarmac to sand/grass. What do you think is going to happen? If you're near 100% of lateral grip, losing just a few % will cause a spin, losing most of that 70-80% will do the same. But as I said it can be saved and I've done it many, many times, it's throttle and steering input for the most part.

 

[Imari]

It might be perfectly normal in GT and it might be something you just have to guard against at all cost when playing, and I get that the incident shown in the OP is at a bit of an extreme force/direction angle thing, but it's still way too much vs. real life. It DOES matter what drivetrain configuration you have as to how much slippage one rear tire can encounter to affect the entire behavior of a car. A one-tire drop-off shouldn't throw the whole car in the example completely around.

You dip one tyre in the dirt. Suddenly the back axle has roughly half the grip that the front axle does. Car is massively unbalanced, spin ensues.

Notice that in all the RL videos posted, even if one wheel hits the dirt the driver makes sure that one of the wheels on the other axle gets into the dirt very quickly. That evens up the grip between the front and rear of the car, and prevents the spin.

The OPs mistake was trying to keep it on the road. It's not possible in that situation, unless you're well under the grip limit already. Your choices are run wide into the dirt, or spin. It's then finding the appropriate inputs to make sure what you want to happen, happens.

GT has some weird things with it's physics sometimes, but I'm pretty sure that isn't one of them.

 

[bluecharger]

Why not? That wheel has lost traction while the others haven't, therefore it's going to get swung around, just like if you were to break traction at the rear by pulling the handbrake.

One of the major accidents I was involved in (riding in the back, not driving) happened like the OP's video. As my mother swerved to miss a drunk driver pulling across the road directly in front of us, the rear tire with load on it dipped into the sand along the road edge, it span the car around 180 degrees even though my mum was counter steering, where the vehicle then hit the edge of the other side of the road and performed 3 flips. We were doing 70mph at the time in a front wheel drive car.

A swerve is much different from a controlled turn. I don't know how much of a drop-off your Mom encountered (sorry about that, btw.) or any other parameter involved in your accident other than the speed you quote. I have, however, driven everything from 2 to 12 wheelers in the last 32 years and while I admit to some conceptual possibility, the game has it too severe. I'm not going to argue this for days; the OP had a point to make, started getting buried with pooh-pooh pseudo-PD nonsense and I spoke up for the OP. You simply can't dissect this to death; common sense and actual experience has to inform you at some point when this game is poppycock. The OP's example was no extreme angle, no huge side-load, no precipitous drop-off, and the car was LOST with one rear tire barely inches off the road surface. BS, plain and simple. Race car videos and non-relatable numbers will not cover this. I do hope some day you all find out driving is not nearly as dramatic or ever-exciting as this game portrays. That's it, end of my participation.

 

[Wide Boy]

Grass is pretty slippery very much so if it is at all damp, dew can scare the life out of you with how quickly things let go.

 

[Imari]

The OP's example was no extreme angle, no huge side-load, no precipitous drop-off, and the car was LOST with one rear tire barely inches off the road surface.

Is there some sort of difference in grip between dirt that is two inches from the road surface and dirt that is two feet from the road surface?

 

[axel edwards]

This would happen in real life I mean watch any motor race one I can think of specifically is the 2012 Belgium GP where a HRT racing car had its wheel on the grass under breaking and it spun round and hit the barrier so there is nothing wrong with the physics.

 

[axel edwards]

also if u think it cannot be saved here is an example of a save in this situation

I had just touched the gravel with my rear tire after slideing round the corner and it threw my car into a slide which I saved

 

[Johnnypenso]

A swerve is much different from a controlled turn. I don't know how much of a drop-off your Mom encountered (sorry about that, btw.) or any other parameter involved in your accident other than the speed you quote. I have, however, driven everything from 2 to 12 wheelers in the last 32 years and while I admit to some conceptual possibility, the game has it too severe. I'm not going to argue this for days; the OP had a point to make, started getting buried with pooh-pooh pseudo-PD nonsense and I spoke up for the OP. You simply can't dissect this to death; common sense and actual experience has to inform you at some point when this game is poppycock. The OP's example was no extreme angle, no huge side-load, no precipitous drop-off, and the car was LOST with one rear tire barely inches off the road surface. BS, plain and simple. Race car videos and non-relatable numbers will not cover this. I do hope some day you all find out driving is not nearly as dramatic or ever-exciting as this game portrays. That's it, end of my participation.

The general physics and common sense behind it are explained above and it's hardly poppycock. It's a matter of tire load + grip lost at the lateral g limit + steering input + throttle...pretty simple.

 

[lmracer]

I've done this in real life with my car on a racecourse. What we are seeing in your video is correctly represented. Instead of using the throttle, you should have gone neutral and tried to center the car's inertia to save it. Once you throttled and added more load to the outside tire, it will lose traction and it will want to 'lead'. (whatever tire locks, leads) Look at it again and analyze the lateral acceleration you are asking of the car. the tire could simply not cope with the lateral acceleration in the low traction condition.

Edit: Imagine suddenly a lunch tray is placed under the tire that goes off. Make sense now?

 

[Dodzzz]

I've done this in real life with my car on a racecourse. What we are seeing in your video is correctly represented. Instead of using the throttle, you should have gone neutral and tried to center the car's inertia to save it. Once you throttled and added more load to the outside tire, it will lose traction and it will want to 'lead'. (whatever tire locks, leads) Look at it again and analyze the lateral acceleration you are asking of the car. the tire could simply not cope with the lateral acceleration in the low traction condition.

Edit: Imagine suddenly a lunch tray is placed under the tire that goes off. Make sense now?

Thanks everyone for the inputs! I appreciate that
I understand it all.. but still in my opinion, the other 3 tires (both front and rear right) are still on tarmac gripping properly..
I don't think just one rear left tire lose grip could drag the whole tires lose all grip..and it's an FF car anyway, even if all tires lose grip, my car should just (spun gently) and thrown deeper into the dirt area..

 

[gtracedriver1]

I hate the grass in Mt.Panorama. The track is too narrow and very difficult for 2 cars side by side pretty easy to touch grass in the final sector. At high speed a little touch on grass and you are basically a passenger. Very annoying. I think they made it too slippery. But on some tracks it is ok I guess.

 

[pyrates]

Thanks everyone for the inputs! I appreciate that
I understand it all.. but still in my opinion, the other 3 tires (both front and rear right) are still on tarmac gripping properly..
I don't think just one rear left tire lose grip could drag the whole tires lose all grip..and it's an FF car anyway, even if all tires lose grip, my car should just (spun gently) and thrown deeper into the dirt area..

And it would't if the car was in a neutral state. In your case most of the load is on the tire that loses grip though. The tires that still have grip carry very little load at that point.

 

[super_gt]

 

[Imari]

Thanks everyone for the inputs! I appreciate that
I understand it all.. but still in my opinion, the other 3 tires (both front and rear right) are still on tarmac gripping properly..
I don't think just one rear left tire lose grip could drag the whole tires lose all grip..and it's an FF car anyway, even if all tires lose grip, my car should just (spun gently) and thrown deeper into the dirt area..

When you're on flat tarmac, all four wheels are contributing about the same amount to the total grip.
When you're going through a hard right hand corner, the vast majority of the grip is coming from the two left hand wheels, the outside wheels. Nearly none of the grip is coming from the inside wheels.

You can test this yourself. Find a corner with grass on the apex. Go through as fast as you can as close to the limit of grip as you can. Try and slip your inside wheel(s) over the grass on the apex. You might slide a little bit wider than you otherwise would, but very little of consequence will happen.

As you've already seen, when you try and do this with the outside wheels the consequences are dramatic.

So if I pull some random numbers out of my butt, and we say that the outside wheels are contributing 40% each of the total grip, and the inside wheels are contributing 10% each when going through a hard corner. If you put an outside wheel off you're losing a huge proportion of your grip all at once.

Those numbers are probably way off and someone will correct me, but they demonstrate the point.

If you were just losing it at both wheels it wouldn't be so bad, as you can see from the real life videos. Cars just slide wide. But if you're losing it at one end of the car, suddenly it's massively unbalanced. You still have 50% grip trying to turn the front of the car from the front two wheels, and 10% plus a little bit from grass trying to turn the rear. Bad things are going to happen.

Put RS on the front and CH on the rear of your car. It's hard to drive, but it's doable. Now add in that there's a sudden change from RS/RS to RS/CH, and you don't know exactly when it's going to happen. That's what makes it so hard to catch.

The best response is to get off the throttle and steer out of the corner, into the gravel. The back has lost grip, so it will go wherever it wants to until it gets grip back. Until then, your job is to keep the front of the car at the front. Accelerating doesn't help, because you're working against a rotating force and acceleration (and braking) is linear. At best it does nothing, at worst you flick the car round even harder.

Steer into the slide, wait for the rear tyres to hook up again, and then power out of it. Even on grass, it's very catchable if you see it coming early enough, both in real life and in the game.

It sucks that there's nothing you can do to avoid going off, but if you've got a wheel on the grass you've already made the mistake. All you can do is try and minimise the time lost to that mistake.