Body roll too exaggerated?

[crimson_menace]

As most of you know, the GT series has been known for it's lifelike physics, and stunning visuals.

I've been playing since GT1, and I've recently noticed something a little bothersome.

When driving in a car with soft springs/dampers, the body rolls with enertia. Obviously. But in some cars, it seems, that the roll is a bit much.

In a C4 Corvette, for example. Heavy braking seems to cause unnaturally high body roll. In most cases, from what I've seen IRL and in videos, the body roll isn't nearly what GT shows it to be, IMO. It seems, with almost any soft-springed car, when the brakes are hit, you're plowing the road with your bumper.

What do you guys think about it? Too much body roll, or am I knit-picking?



EDIT: I've also recently played GT:HD, and noticed the same thing. Even light taps on the brakes causes the car to lurch. (@ 20-30 mph.)

 

[Scaff]

As most of you know, the GT series has been known for it's lifelike physics, and stunning visuals.

I've been playing since GT1, and I've recently noticed something a little bothersome.

When driving in a car with soft springs/dampers, the body rolls with enertia. Obviously. But in some cars, it seems, that the roll is a bit much.

In a C4 Corvette, for example. Heavy braking seems to cause unnaturally high body roll. In most cases, from what I've seen IRL and in videos, the body roll isn't nearly what GT shows it to be, IMO. It seems, with almost any soft-springed car, when the brakes are hit, you're plowing the road with your bumper.

What do you guys think about it? Too much body roll, or am I knit-picking?



EDIT: I've also recently played GT:HD, and noticed the same thing. Even light taps on the brakes causes the car to lurch. (@ 20-30 mph.)

Uh if you run with dampers and spring that are too soft for the car and the load transfer that's exactly what should be happening.

In fact the degree of body roll on soft springs and dampers is under-played, from the videos shown so far of GT5P its much closer to what should be happening in the real world.

Dampers in particular are far to firm even at the lowest settings, given that its almost imposable to set the dampers so soft that the spring oscillations become uncontrolled. Always remember that dampers actually have little to do with how far a car moves under load transfer (that's principally down to the spring rates), rather they determine how quickly the car moves under load transfer and how well the springs natural cycle is controlled.

Road car set-ups are not geared to the levels of force that can be experienced on the track, hell you take a road car and brake to the tyres true limit in the real world and you will be close to removing the front bumper on a lot of cars.

The following video quite clearly shows the degree of body roll that can occur in a road car when taken on track, keep in mind that most of these will also not be being pushed right the way to the limit (as is so easy to do in GT).




Regards

Scaff

 

[Rotary Junkie]

Right on, Scaff.

If anything, it is underplayed to a point that realism can't quite be claimed. Add in the under-rotation of the car when the rear tires break loose under power, and suddenly it's not the real driving simulator.

 

[crimson_menace]

Good to know. Thanks guys. 👍

 

[Wolfe]

Scaff's absolutely right in saying body roll is underpronounced in GT4. However, I've also noticed the phenomenon you were referring to with the C4 -- "body roll" to the front is called nose dive, or just dive, by the way -- and that's definitely not realistic at all.

The speed of the movement is too slow, and if you're using the "bumper" cam, the degree of the movement is too severe. I don't know about anyone else here, but I've never seen a car bob like a drinking bird when it slams on its brakes and screeches to a halt.

 

[Tornado]

The speed of the movement is too slow, and if you're using the "bumper" cam, the degree of the movement is too severe. I don't know about anyone else here, but I've never seen a car bob like a drinking bird when it slams on its brakes and screeches to a halt.

Or the Volvo 240. Classic!

 

[crimson_menace]

Scaff's absolutely right in saying body roll is underpronounced in GT4. However, I've also noticed the phenomenon you were referring to with the C4 -- "body roll" to the front is called nose dive, or just dive, by the way -- and that's definitely not realistic at all.

That's exactly what I'm talking about! Front-end diving....

 

[Rotary Junkie]

Well, I think that is due to the lack of stops in the suspension geometry. If the springs and shocks CAN be compressed until the car hits the ground under a given load, the car WILL hit.

 

[Scaff]

Scaff's absolutely right in saying body roll is underpronounced in GT4. However, I've also noticed the phenomenon you were referring to with the C4 -- "body roll" to the front is called nose dive, or just dive, by the way -- and that's definitely not realistic at all.

The speed of the movement is too slow, and if you're using the "bumper" cam, the degree of the movement is too severe. I don't know about anyone else here, but I've never seen a car bob like a drinking bird when it slams on its brakes and screeches to a halt.

A modern car with a descent suspension set-up (as in dampers and springs) and suspension geometry configured to maximise anti-dive would not behave in that manner you are correct.

However to issue a blanket 'not realistic at all' is not accurate either, older vehicles can most certainly react in this manner, particularly with poor or antiquated dampers (the principal factor in how quickly dive or squat occurs).

The video I posted above clearly shows just how much roll, dive and squat can vary from car to car. Now GT4 (or any of the GT series) is certainly not 100% accurate in this regard, but the basics are OK, just underplayed.

The principal issue with GT4 (as I mentioned above) is down to the damper rates having a minimum value that is set quite high, as a result its almost impossible to set them too soft. As I also mentioned the video for GT5P does indicate that improvements in this area have been made.


Regards

Scaff

 

[Omologato]

Or the Volvo 240. Classic!

I can personally tell you that in real life, the 240 Estate does not dive to the point that the front air dam scrapes.

 

[dylansan]

Yes but most of the time your hitting the brakes all the way in GT, and holding them, from high speed, to get it to bottom out IIRC. In real life, I doubt you've tried that?

 

[syclone538]

Yes but most of the time your hitting the brakes all the way in GT, and holding them, from high speed, to get it to bottom out IIRC. In real life, I doubt you've tried that?

Why would you doubt he has tried it? All of my friends that are at least somewhat into cars have tried exactly that in at least 1 car. And I agree the nose dive is excessive in most of the cars that I've driven before modifying the suspension.
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edit
I guess it could depend on what you call high speed, I’m talking about 50-80 mph to 0. I’ve never personally done an all out 100 to 0 mph.

 

[Wolfe]

Scaff, are you trying to say that older cars with antiquated shocks won't bounce a bit after screeching to a stop, and will instead dive forward, come to a stop, then slowly and calmly return to level, like in GT4? That says to me that the car has weak springs and very strong shocks.

Cars in GT4 don't have to be old and antiquated to do this, anyway.

 

[Scaff]

Scaff, are you trying to say that older cars with antiquated shocks won't bounce a bit after screeching to a stop, and will instead dive forward, come to a stop, then slowly and calmly return to level, like in GT4? That says to me that the car has weak springs and very strong shocks.

Cars in GT4 don't have to be old and antiquated to do this, anyway.

No quite the opposite, my main point was that blanket comments that cars well never behave in 'x' manner are rarely accurate given the range of possible situations that can occur. In regard to GT4 dampers I have always maintained that they can't actually be set to realistically soft (or underdamped levels) and that even an FC setting of 1 is still too stiff for many cars, particularly the lighter ones.

This thread....

https://www.gtplanet.net/forum/showthread.php?t=74732&highlight=dampers

...covers my thoughts on GT4 dampers and how they relate roughly to real world settings in a lot of detail, in a nutshell I believe that the range of damper settings in GT4 basically run from Medium to Firm, with almost no ability to truly under-damp a car.

Hence the reason why I have said a couple of times above that you can't set a car up to show true uncontrolled spring oscillations, you simply can't get teh dampers soft enough.


Regards

Scaff

 

[Wolfe]

Well then, Scaff, I must respectfully suggest that one of us is misreading the other, because this sequence of statements doesn't make sense:

The speed of the movement is too slow, and if you're using the "bumper" cam, the degree of the movement is too severe. I don't know about anyone else here, but I've never seen a car bob like a drinking bird when it slams on its brakes and screeches to a halt.

A modern car with a descent suspension set-up (as in dampers and springs) and suspension geometry configured to maximise anti-dive would not behave in that manner you are correct...

...older vehicles can most certainly react in this manner, particularly with poor or antiquated dampers (the principal factor in how quickly dive or squat occurs).

Scaff, are you trying to say that older cars with antiquated shocks won't bounce a bit after screeching to a stop, and will instead dive forward, come to a stop, then slowly and calmly return to level, like in GT4?

No quite the opposite, my main point was that blanket comments that cars well never behave in 'x' manner are rarely accurate given the range of possible situations that can occur.

 

[Scaff]

Well then, Scaff, I must respectfully suggest that one of us is misreading the other, because this sequence of statements doesn't make sense:

Well the problem (or confusion) for me was this...

The speed of the movement is too slow, and if you're using the "bumper" cam, the degree of the movement is too severe. I don't know about anyone else here, but I've never seen a car bob like a drinking bird when it slams on its brakes and screeches to a halt.

..because all the drinking birds I had as a kid, when started, would continue to 'bob' up and down, gradually slowing down until they stop. Which is more extreme than you would find on an underdamped car, but still basically the same. The dampers not being able to total control the spring oscillation cycle and the car 'bobs' on the springs before coming to a rest. Something I most certainly have seen and felt in a number of older cars, particularly after a violent and/or sudden load transfer.

Then again its quite a few years since I had a drinking bird

Scaff

 

[Mad Matt]

I think you're more or less agreeing here! I'm in the process of fitting new springs and shocks to my Fiat, so I'll be curious to see how it relates to the changes modelled in the game. My plan is to take it down to the ring, but I doubt I'll have the nerve to do it anywhere near as fast as in the game (or perhaps I won't because of common sense?).

 

[Mad Matt]

Forgot to mention, I've already fitted a strut brace. If I relate that to chassis stiffening in the game then yes there is something smiler to what I feel in real life and the game.

If I might use a simile, I'd say it's like comparing Chinese food from your local restaurant with the food you get in China. The local food puts you in mind of the real thing, but you can feel something is lacking!

 

[Leonidae]

I can personally tell you that in real life, the 240 Estate does not dive to the point that the front air dam scrapes.

It does so in GT4 because it's about half a ton overweight. If it would be lighter, that wouldn't happen. And I don't think that it's too exaggerated, not after driving my sister's '95 Astra wagon..body roll, nose dive, bouncing tyres under acceleration.. everything is spot on.. too bad that GT4 doesn't feature broken gearbox.

 

[Tornado]

Yes but most of the time your hitting the brakes all the way in GT, and holding them, from high speed, to get it to bottom out IIRC.

Whether it was tried in real life or not (who hasn't done a panic stop at least once in their life?), you hardly need to stomp on the brakes to get that much dive out of the Volvo 240. Half braking power is enough to do it, and it does it regardless of speed.

 

[Wolfe]

Well the problem (or confusion) for me was this...

..because all the drinking birds I had as a kid, when started, would continue to 'bob' up and down, gradually slowing down until they stop. Which is more extreme than you would find on an underdamped car, but still basically the same. The dampers not being able to total control the spring oscillation cycle and the car 'bobs' on the springs before coming to a rest. Something I most certainly have seen and felt in a number of older cars, particularly after a violent and/or sudden load transfer.

Then again its quite a few years since I had a drinking bird

Scaff

I don't think the drinking birds I've seen were as fast as you're describing. Perhaps I could have chosen a better metaphor.

 

[Parnelli Bone]

Dampers in particular are far to firm even at the lowest settings, given that its almost imposable to set the dampers so soft that the spring oscillations become uncontrolled.

Regards

Scaff

This is something me & Sucahyo noticed in GT2--you set dampers on their minimum setting, and the car still behaves relatively safely. In GT1, however, if you put dampers on "1", most cars start bouncing like mad....going up on 2 wheels in turns and stuff. The spring oscillations become deadly.

 

[Omologato]

While it's true that any car will dive when the brakes are applied, I will still argue that in real life the Volvo does not scrape the air dam. I autocross my Volvo during the summer months and have performed many quick stops, especially on courses with long straights followed by a sharp turn, and I have never been able to replicate what happens in GT4.

As Leonidae said though, the car is incorrectly over weight in GT4. I don't recall the conversion to kilograms, but in pounds it weighs 3,100 for an automatic 240 estate in real life.

 

[Tornado]

I don't recall the conversion to kilograms, but in pounds it weighs 3,100 for an automatic 240 estate in real life.

And the one in GT4 is a stick, too.

 

[Wolfe]

And the one in GT4 is a stick, too.

Everything in GT4 is a stick. I guess Polyphony Digital was too lazy to model the acceleration and shifting characteristics of a torque converter.

 

[Tornado]

Everything in GT4 is a stick. I guess Polyphony Digital was too lazy to model the acceleration and shifting characteristics of a torque converter.

That's not what I meant.

 

[Wolfe]

That's not what I meant.

I don't know Volvos that well, but I don't know how you could determine the transmission the GT4 car is supposed to have without simply going by the way it shifts.

 

[Tornado]

I don't know Volvos that well, but I don't know how you could determine the transmission the GT4 car is supposed to have without simply going by the way it shifts.

Because the 240GLT has 5 gears, if I'm not mistaken, and Volvo never sold the 200 series with anything more than 4 speeds if it was an automatic. I was referring strictly to how cars with sticks weigh less than those with slushboxes.

 

[Wolfe]

Because the 240GLT has 5 gears, if I'm not mistaken, and Volvo never sold the 200 series with anything more than 4 speeds if it was an automatic.

Right. I should have thought of that.

I was referring strictly to how cars with sticks weigh less than those with slushboxes.

I'm aware of this.

 

[Rotary Junkie]

Gear count?

Oh, and drive either of the Jag R-Performances. Note that they idle at a couple MPH rather than sitting there. The only inaccuracy is that the converter can be fully released.