Nose-Tipping, Rollovers, and 'Broken' Handling of MR Cars: An Analysis of GT6's Center of Gravity

mister dog
Meh take a map of the US and ask the average European to point out Nebraska or Pennsylvania and he wouldn't have a clue neither; a bit the same concept as with Europe and it's countries.
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Ha! That's true. Then again, if you ask the average American to point out NE, he'd probably just point to the middle of the map and hope for the best.

(If anyone's from NE, btw, please know I'm not dissing your state or anything. Since I'm from Maine I guess don't really have the right to mock anyone else's state. Haha)
 
No expert in the field, but all this hating on MR cars being broken is ridiculous. In real life you really think you can just pile drive the throttle and expect the car to go? A supercar in real life isn't going to handle ultra sharp the entire time? People asked for more realistic better physics yet all I see around here lately is constant complaining.

If you are on high grip tyres, when they break traction the reaction will be more extreme. I was in a BMW on racing hard tyres, a ton of grip, and then when it breaks BANG you are around. Supercars are on sports hard tyres generally that aren;t particularly grippy.

As for the Deltawing mentioned last page... an excerpt from an interview by TopGear.com about the car prior to the Road America ALMS in 2012.



"...Technique is important. You drive the car quite conservatively: brake in a straight line, turn in fast, then immediately get back on the power. It's the rear that's doing all the work here, so you need to use it. Use the traction, maximise the tyre grip. That's why the guys that race it have found that it's fast in different places to other cars. It behaves differently."

"...cars with heavier active downforce can brake later, right up to the apex, a technique called trail braking. The DeltaWing is slower into corners, but quicker out of them. And down the straights it's much faster. Cars with big wings generate more and more downforce the quicker they go, which really harms acceleration. The DeltaWing just keeps on pulling. It has a smaller frontal area and it's shape means it pushes the air out of the way more gradually.

Even with a mere 300bhp from a 1.6-litre turbo (an engine distantly related to that of the Nissan Juke), it was clocked at Le Mans at over 192mph. I've got no idea what speed I was doing down Road Atlanta's back straight as I haven't had a chance to look at the telemetry yet, but the DeltaWing was so planted and stable that big speeds are less scary here than in any other racing car I've driven. It doesn't hunt or follow cambers or dart or weave. It's remarkably vice-free..."

"...It just drives cleanly and naturally. It's actually a ridiculous amount of fun to drive, not least because of the way the acceleration never lets up as it hurls its way between corners - no appreciable turbo lag, just this intoxicating eagerness to get to the next corner as soon as possible. And when you get there, the speed washes off so easily, and then the front tracks so lightly and accurately in, it's as if it has no inertia. Which, compared to other racing cars, it doesn't. The steering's lovely, too. You know exactly where you are with it because the narrow front tyres are easy enough to turn that power steering was deemed unnecessary..."
 
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That deltawing video makes decent sense to me. High powered rear heavy cars want to do wheelies when accelerating in the first place (see drag racing). Of course, when building a rear heavy race car you will take this into account, adding downforce or changing the suspension/weight setup to make sure it keeps it's front wheels on the ground. In the deltawing that stability is given by the downforce from the 'ground effect' created by the airflow between the floor and the road. However, the moment you launch the front wheels over a curb, the 'ground effect' goes away, and there's nothing keeping the front on the ground.

Accelerating over a bump in a rear heavy race car is dangerous at the best of times. In a rear heavy race car with ground effect, it's lethal.
 
iLex
It seems to happen in two phases. First he hits the curb, then for a split second nothing much happens and then he suddenly flips over. My sense of forces, which I developed by living on earth for almost 34 years now tell me this is not natural... If it was one fluid movement I maybe could've lived with it.
It just seems like there is an invisible guy at the side of the road giving it an extra push or if he suddenly catches a huge burst of wind from the side.

This is what I see in many of the roll over videos, especially the ones that are on the edge of rolling over. They all suddenly get a push (indeed like a bomb explodes under the car) and flip over. In many cases the gravity should have pulled the car back to the road or at best should've made it a close call, but instead the car just gets this huge kick and starts flying.

If physics truly worked this way we would see a lot (a LOT) more cars flip over in real life.
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This... /\ +1, While I was turning into the corner, I'd hit that apex every lap previously and it's the point at which I begin my exit. So there wasn't any steering inputs at the time of the roll, it honestly caught me by surprise. Felt as though there was string attached to the tires pulling them upward.
If you watch I turn in and aim for the apex, but I use that time to straighten the car out to get back on power. So there was really little to no steering and the speed was relatively low.
 
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z06fun
This might be a good place to say that, in real life, MR cars have a much larger change in balance with throttle vs. say a typical front engine, rear wheel drive car. For an MR car, weight change on the front wheels with throttle changes can be HUGE. In real life, if an MR car starts out fairly neutral in handling, it can have a lot of oversteer under throttle lift. For GT6, to me it feels like PD improved these physics by A LOT from GT5, where that aspect didn't really seem to exist. From my 15 years of real life racing, MR cars can be harder to drive compared to others because of the huge balance change with throttle, especially if they don't have the real long wheel base of something like an audi R10 LM type car.

The ar flipping is a whole different issue :)
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How's the fake version of your Lotus?

Only experience I've had with the MR cars in game so far is when I got giddy to see they put in the Dino and then proceeded to loop it the first time I saw a corner. Though trailing throttle fixed it and it was a fun car after that, just had to make sure to be careful and for gods sake no trail braking. :lol:
 
I find that the Toyota MR2 GT-S '97 still a handfull to drive. Under throttle, it is more tail happy than a Silvia! I do not tail brake, I do not lift the accelerator mid turn, and the car is likely to spin out even on SH tyres.

I know that maybe it's not a good comparison, but I've tried the Ferrari 365 GTB4 in game. This car has 50% more power and torqe, weighs a bit less and was produced in 1971! Using SH tyres it is almost impossible to spin even if I slammed the accelerator mid-corner.

I refuse to belive that both MR2 and 365 GTB4 have accurate handling in game.
 
Check the tire width on both cars, GT6 now take account the contact patch. I have 400PS Zeek tuned MR2 GTS on comfort soft replica and it's very much great to drive, a bit wild, but can be pushed hard. The real MR2 GTS have 225/50 R15 rear tire and 195/50 R15 front. Comparing both needs to take into account their real life counterpart tires, Ferrari 365 GTB is FR with 52% front weight bias, where as the MR2 is rear biased MR car. The old Ferrari have Pirelli P4000 215/70 R15 touring tire - in GT6 it should have comfort hard or medium tire stock, while the MR2 would have comfort medium stock. Can't compare both cars with same SH tire.
 
Rods
Ha! That's true. Then again, if you ask the average American to point out NE, he'd probably just point to the middle of the map and hope for the best.

(If anyone's from NE, btw, please know I'm not dissing your state or anything. Since I'm from Maine I guess don't really have the right to mock anyone else's state. Haha)
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I'm FROM 'MERCA AND I!!!!

WELL...

Unfortunately have to agree with you :(
 
I wonder if the cars behaving odd when rolling has to do with moment of inertia?

brief explanation - you have a barbell with two 10 lb discs on it, one at each end, and you try to rotate it in helicopter fashion. Now if you do the same but with the discs are both near the centre, it's easier. In both cases the barbell has the same mass and the same centre of mass, but it's easier/harder to rotate depending on the distribution of mass along its length.

I would hope (but not bet!) that PD has centre of mass modelled correctly. But how on earth would you model moment of inertia?! You'd have to know the location and size of most of the important masses in the car's body; engine, fuel tank, gearbox, differential, wheels -this sounds like a lot of work. I reckon this could account for the unnatural floaty-rolling people have seen.

Failing that you'd have to get a car and mount it in a "lawnmower man" style 3-axis gimbal, and measure the torque needed to spin it around (!)

Cheers,

Bread
 
There are some reports that the handling on some MR cars has changed after 1.03 patch. Gonna try out stock Toyota MR2 and Lancia Stratos when I get home after work...
 
AI was driving this. Replay showed a nose stand every lap on this corner and only in this braking zone, nowhere else.

image.jpg
 
CeeJay
Oh GT physics! :lol:

Actually I'm a little more perplexed by the shadowing on the car.. Where is the other light source that is causing the second shadow under the car? :confused:
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That double shadow effect is carried over from GT5.

The lighting model seems to cast at least two shadows. One from the light source such as the sun or trackside lighting, and one cast straight down. If the car is not airborne, the resulting appearance is quite realistic, but when a car flies, it's horrible.

Other examples follow from both GT5 and GT6:-

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The above from a home made track in GT5,


and below from GT6. It's not so obvious in this shot since I deliberately lowered my point of view to minimize the effect, but if you look closely, you'll see a fainter shadow directly under the Stingray.
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Furinkazen
No expert in the field, but all this hating on MR cars being broken is ridiculous.
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I think it's perfectly reasonable. The opposite I see to the MR broken idea usually comes in two flavors:

1. "I can drive it fine"

2. "This car acts the way it's described in this source"

The first argument obviously doesn't say much since drivability and accuracy are different.

The second looks good, but may not be. Many sources of automotive information like to be not so objective. Or at best, not very precise. Reading something like "The car will bite your head off with oversteer" doesn't mean that the car oversteers at all speed with any tap of the wheel. Ideally you'd like to see a chart of grip vs slip angle for front and rear and then try to reproduce this chart in game. Unfortunately this is unlikely to happen.

I myself don't have an opinion on GT6 MR since I've never driven one in game, but the typical counter arguments I've seen done look conclusive.

bread82
I would hope (but not bet!) that PD has centre of mass modelled correctly. But how on earth would you model moment of inertia?!
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Ask the manufacturer, it probably get spit out of CAD automatically.
 
The moon missions have different gravity/physics. Maybe that is somehow screwing with earth based tracks?
 
I'm determined not to join the thread as a grumbler, Most but not all of the MR cars that I've driven to date in gt6 do have a sudden rotation towards the inside of the corner, the effects are still there with the lower powered mid engine cars but not as prominent..but even at very low speeds in the R8 LMS around 50mph on throttle. I have no problem braking in these cars, its when the car has just settled holding the throttle at eg. 50% and boom around she goes. I'm pretty sure a real R8 wouldn't be letting go at 50mph. I can tune it out to a degree but it seems a bit off to me...I just drive around it but I still question it.
 
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GBO Possum
AI was driving this. Replay showed a nose stand every lap on this corner and only in this braking zone, nowhere else.

View attachment 100291
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This is the only car I have seen this issue with, don't know which model Mitsubishi Lancer it was as AI was driving it.
Suppose should buy them to find out but suspect it is a suspension issue, to soft causing weight transference & stoppies.
Never seen in a car but easy enough to do on a motorbike, trial riding you sometimes set your suspension to let you do just this or pull easy wheelies.

Low speed stoppie is achieved by accelerating transferring the weight back then breaking throwing it forward & having the suspension set up to let the vehicle pitch & transfer the weight. So long as your tyre does not break grip its easy enough on a bike
 
I think the physics are a major step in the right direction for GT6. However, my main issue is they're just the tiniest step too far. If the weight transfer was dialed back by just a tiny fraction, with no need for PD to adjust grip levels in order to try and fix it, the physics would become more realistic.
 

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