Forza 4 vs GT5 physics (read the first post before contributing)

[1241Penguin]

It does if you try to accelerate on a banked corner like on the oval tracks and on certain corners of the Nordschleife (not the Karussell) for example.

I really don't think you understand what this "RWD torque steer" is. Frankly, if GT5 can't even replicate "side-stepping" on a banked track, then it really isn't a simulator.

Go onto a flat surface, and then launch a car. In GT5, you'll just accelerate up to speed no problem at all. In real life though, as shown in the videos me and Nismo34 posted, you will have to correct the, what I believe, uneven torque distribution between the rear wheels.

Then again the video i allready posted:

http://www.youtube.com/watch?v=vD9AW-EB3vo

The Porsche does not sidestep and the steering wheel is straight at take off.

Did you not read what I wrote earlier? Just because there is one instance of a RWD launch without torque steer doesn't mean all RWD launches don't.

 

[crazy_cj]

1241Penguin knows what hes talking about.

I have a 200sx. its no ferrari by any means, but it has a modest 255kw at the rear wheels. dumping the clutch in 1st gear at full boost will side step right up to 3rd gear.

im still baffled how the general consensus still considers gt5 the most realistic sim. I dont get it. forza 4 has a tire model, better suspension model, and just better physics all round. its no comparison.

this is coming from a ps3 fan.

 

[Scaff]

Side steping does rarely occur in real life and most of the time its due to the surface conditions. Many roads tend to lean to one side and that causes a car to sidestep. Spinning the tires while accelerating might cause a car to sidestep, but mostly because the road is either banked or the front wheels not facing foreward perfectly.

Uhhh no.

Road camber is not a major factor in a car sidestepping.

Unequal torque distribution between the driven wheels in one of the two main factors and the other is the tractive force that can be dealt with at each driven wheel. This is rarely in the real world equal between the two driven wheels as few cars have a natural 50:50 Left right balance and even fewer when a driver is in the car. As a result you have uneven torque being sent to tyres that have different tractive limits.

That one tyre will loose traction before the other is not a major surprise, and as a result if you want to getting a RWD car to step-out is not difficult. You don't get massive amounts with most cars (its a few degrees) unless they are kicking out a lot of torque. It can be avoided by throttle modulation and that's what you would want to do with any race or drag launch, after all it looses you time and that's exactly what you don't want, however once you take gearing into account you can achieve this in almost any reasonably powerful RWD car if you launch them with the throttle wide open and just dump the clutch.

However its perfectly possible and doesn't require a cambered surface at all, to be blunt GT5 simply doesn't replicate this at all, regardless of tyres used (all the way down to CH) or TC setting.


Oh and can we all follow the AUP when posting in here, in particular.

You will not use “textspeak” (“r”, “u”, “plz”, etc.) in your messages. Decent grammar is expected at all times, including proper usage of capital letters.

 

[thelvynau]

Wasn't this discussed in for a vs gt5 physics thread?

 

[Samus]

Yes, and Scaff posted some great videos that highlighted the problem.

 

[crazy_cj]

Yes, and Scaff posted some great videos that highlighted the problem.

Does anyone have the link to the videos?

 

[Samus]

 

[crazy_cj]

Thanks heaps.

 

[USARMYCOMBATVET]

1241Penguin
Im still baffled how the general consensus still considers gt5 the most realistic sim. I dont get it. forza 4 has a tire model, better suspension model, and just better physics all round. its no comparison.

this is coming from a ps3 fan.

I have owned Gran Turismo 5 since release.
I have owned Forza 4 since release.
I am a gamer at heart and try very hard not to judge others for their choice in gaming platforms.
I am aware there are other games which may outdo the games I am about to mention. This is my perspective on side step in GT5.

I may get butchered for this but, here goes:

Forza 4 has side-step. GT5: very minimal at best(exceptions being very powerful cars). In wet conditions, you bet your 🤬 GT5 is the best simulation I've ever seen when it comes to racing in the rain. It's good enough for me because I'm not a race car driver. I'm just a guy who loves cars, trying to enjoy them in a game.
In Forza 4, I almost always am forced to launch at about 2000-4000rpm or I side-step/lose traction on one wheel--call it what you like--it happens in Forza 4 and not GT5 on most cars. I find that short shifting doesn't affect the side-step effect much for me in this game. In GT5, I can short shift and it doesn't side step at all. These are simply my observations of two games I own and enjoy. I hope I've contributed something useful to this community and this thread.

 

[llNovall]

Please explain why a car actually side steps, then try again somewhere that isn't perfectly flat with perfectly uniform tyre grip and perfectly central weight balance. Think about what GT5 is simulating, now explain why Forza does side step in that situation.

Not all cars sidestep. Sidestepping occurs due to torque transfer thru the drivetrain (torque=twisting force). That twisting force causes the inertia that makes the car sidestep to the right. Most of today's modern cars do a great job of controlling this through proper suspension geometry (design) and proper tuning. The '60-'70's muscle cars were the most notorious for sidestepping: tons of torque and old school suspension design. However, with the new aftermarket suspension items offered for these old cars, its now possible to control this on them too. So, to answer why GT5 does not simulate this is simple: they would have had to hard launch every car to see which ones would and would not sidestep, and because each car does so differently. The game would still be inaccurate if they all sidestepped the same ( Forza4).

 

[Scaff]

I have owned Gran Turismo 5 since release.
I have owned Forza 4 since release.
I am a gamer at heart and try very hard not to judge others for their choice in gaming platforms.
I am aware there are other games which may outdo the games I am about to mention. This is my perspective on side step in GT5.

I may get butchered for this but, here goes:

Forza 4 has side-step. GT5: very minimal at best(exceptions being very powerful cars). In wet conditions, you bet your 🤬 GT5 is the best simulation I've ever seen when it comes to racing in the rain. It's good enough for me because I'm not a race car driver. I'm just a guy who loves cars, trying to enjoy them in a game.
In Forza 4, I almost always am forced to launch at about 2000-4000rpm or I side-step/lose traction on one wheel--call it what you like--it happens in Forza 4 and not GT5 on most cars. I find that short shifting doesn't affect the side-step effect much for me in this game. In GT5, I can short shift and it doesn't side step at all. These are simply my observations of two games I own and enjoy. I hope I've contributed something useful to this community and this thread.

GT5 does not have side step at all, not in any car, it still has exactly the same launch issue in this regard that have existed across the entire series.

So, to answer why GT5 does not simulate this is simple: they would have had to hard launch every car to see which ones would and would not sidestep, and because each car does so differently.

Why would they have to test this on every car?

If the physics model is up to the job and the suspension and tyre modelling is in place you don't have to test every car at all, the physics engine and the specs for the car would do it. Pretty every other sim on the market (regardless of platform) models this, do you think they tested every single car individually? What about LFS which is primarily non-licensed track inspired cars?

You can also have the finest suspension set-up in the world, you will not get a car in reality that has perfectly equal load distribution on every tyre at launch, and as a result the driven wheels will not always loose traction at exactly the same time.

The game would still be inaccurate if they all sidestepped the same ( Forza4).

Sorry but the difference in sidestep between cars in FM4 is quite clear to see and they certainly do not all react in exactly the same way at all.


BTW - This is getting merged with the GT vs FM physics discussion for rather obvious reasons.

 

[SlipZtrEm]

Not all cars sidestep. Sidestepping occurs due to torque transfer thru the drivetrain (torque=twisting force). That twisting force causes the inertia that makes the car sidestep to the right. Most of today's modern cars do a great job of controlling this through proper suspension geometry (design) and proper tuning. The '60-'70's muscle cars were the most notorious for sidestepping: tons of torque and old school suspension design. However, with the new aftermarket suspension items offered for these old cars, its now possible to control this on them too. So, to answer why GT5 does not simulate this is simple: they would have had to hard launch every car to see which ones would and would not sidestep, and because each car does so differently. The game would still be inaccurate if they all sidestepped the same ( Forza4).

Side-stepping isn't some value they could just plug into the system for each car: a good physics model would take the uneven distribution of torque into account on cars, and while surely it wouldn't be a perfect representation of real life, it's readily apparent GT5 does not consider these things from a stand still. A Speed 12 or Shelby Cobra on CH tires will still launch straight at the Speed test.

FM4 isn't perfect in this regard either, but it at least models the effects - and no, it's not the same on every car.

 

[NOSWaster]

im still baffled how the general consensus still considers gt5 the most realistic sim. I dont get it. forza 4 has a tire model, better suspension model, and just better physics all round. its no comparison.

GT5 and Forza 4 are not the most realistic sims. iRacing is. Failing you can acquire that, rFactor is still better. Both of them replicate side stepping.

 

[USARMYCOMBATVET]

GT5 and Forza 4 are not the most realistic sims. iRacing is. Failing you can acquire that, rFactor is still better. Both of them replicate side stepping.

Irrelevant Point.

 

[jujunosuke]

@thelvynau

Beta as in playable? Or a simulation?

I am preparing it. Beta will be available at the end of this month probably.
I am probably going to create my own thread later to get feedback from gtplanet community members.

I will let you know when it will be available if you want !

 

[thelvynau]

@thelvynau

I am preparing it. Beta will be available at the end of this month probably.
I am probably going to create my own thread later to get feedback from gtplanet community members.

I will let you know when it will be available if you want !

Awesome sounds good.

 

[Odyofil]

There is no engine brake in GT, just shift down 4 to 1 and watch, and then, go play forza shift down from 4 to 1, then see what happens to car.

 

[hogger129]

I've played them both (played Forza 4 at a friend's place), and I'm going to put my vote in for Gran Turismo 5.

 

[C_Raccoon23]

I voted for Forza. GT5 loses my vote due to the fact cars behave differently depending on what game mode you play. It really bugs me.

 

[sik180sx]

There is no engine brake in GT, just shift down 4 to 1 and watch, and then, go play forza shift down from 4 to 1, then see what happens to car.

I use a clutch and there is definately engine brake in gt5.If i'm in 4th and i shift to 1st,hello compression lock-up.

 

[indoor activist]

Hang on!!!....Are you really claiming that GT5 is an inferior game due to, side stepping? If so, sort your life out.

 

[HighSeasHoMastr]

I think that the claim is that GT5 is inferior because it has nothing resembling a realistic tire model, and the lack of sidestepping is used as an indicator of that.

 

[Samus]

Hang on!!!....Are you really claiming that GT5 is an inferior game due to, side stepping? If so, sort your life out.

Hang on!!! Did you sign up just to post that? If so, sort your life out.

In all seriousness no, nobody is claiming GT5 is inferior because of one issue. They're saying it's inferior because of many issues, that being one of them due to the poor tyre model, as mentioned above.

 

[Nismo34]

I use a clutch and there is definately engine brake in gt5.If i'm in 4th and i shift to 1st,hello compression lock-up.

Right... Next GT5 has an accurate tyre model... No way GT5 has engine braking.. Go down a hill flat out in a samba bus in the highest gear then drop it back to first without using the brake.. What happens next? Yes, it gains speed... This wouldnt happen if it had engine braking...

 

[Ridox2JZGTE]

Right... Next GT5 has an accurate tyre model... No way GT5 has engine braking.. Go down a hill flat out in a samba bus in the highest gear then drop it back to first without using the brake.. What happens next? Yes, it gains speed... This wouldnt happen if it had engine braking...

In real life, if the hill is steep enough and no brake, the car would still go faster, the engine would over rev as the engine would not be able to brake with it's own compression, and the occupants would die in a crash or fall over the cliff. There are so many accidents happened this way due to faulty brakes, they can try engine braking and it would not do anything, the law of gravity still wins. Engine braking can only help to slow down when the brake is also used. On it's own, it does have use on a flat road, but on a steep slope, useless.

Want to prove it, try it yourself, find a hill, roll the car down without brake, use the engine braking and see what happens, but don't blame anyone if you crash. And an advice, never use higher gear when rolling down the hill, change to lower gear before rolling down, it's common sense.

 

[1241Penguin]

Hang on!!!....Are you really claiming that GT5 is an inferior game due to, side stepping? If so, sort your life out.

No one is. All we are saying is that the lack of "side-stepping" is another flaw with GT5's physics compared to Forza 4's. Plus, the way you say what you just said makes it seem like you're trying to suggest that GT5 is the better game by default.

 

[hennessey86]

If anyone still thinks GT5s physics are better than forzas after GT academys sliding round corners to get a fast lap shocker, then wow just wow........................................

 

[Ridox2JZGTE]

In real life, sliding around corners sometimes could be faster, Tsuchiya is known to used the tail slides around corners in his career in JGTC, he won with it several times. I am sure this technique has been used in many different field of motorsports, there's no guarantee a faster lap, but it does help in certain condition.

 

[Scaff]

In real life, sliding around corners sometimes could be faster, Tsuchiya is known to used the tail slides around corners in his career in JGTC, he won with it several times. I am sure this technique has been used in many different field of motorsports, there's no guarantee a faster lap, but it does help in certain condition.

Very, very rarely is it a quicker way around a corner, certainly on a race track its almost never quicker that maximising the last shred of grip a tyre has available.

Now while Tsuchiya did throw in a little drifting in his JGTC days it was mainly showboating when he was well ahead of the rest of the pack, its quite doubtful that he won as a result of it at all. He did also say:

"I drift not because it is a quicker way around a corner but the most exciting way."

All of which is an aside because the techniques required to get a top time in the GTA were simply people taking advantage of the issues that exist within GT5/GTA's physics engine.

 

[Scaff]

Very, very rarely is it a quicker way around a corner, certainly on a race track its almost never quicker that maximising the last shred of grip a tyre has available.

Now while Tsuchiya did throw in a little drifting in his JGTC days it was mainly showboating when he was well ahead of the rest of the pack, its quite doubtful that he won as a result of it at all. He did also say:

"I drift not because it is a quicker way around a corner but the most exciting way."

All of which is an aside because the techniques required to get a top time in the GTA were simply people taking advantage of the issues that exist within GT5/GTA's physics engine.

In real life, if the hill is steep enough and no brake, the car would still go faster, the engine would over rev as the engine would not be able to brake with it's own compression, and the occupants would die in a crash or fall over the cliff. There are so many accidents happened this way due to faulty brakes, they can try engine braking and it would not do anything, the law of gravity still wins. Engine braking can only help to slow down when the brake is also used. On it's own, it does have use on a flat road, but on a steep slope, useless.

Want to prove it, try it yourself, find a hill, roll the car down without brake, use the engine braking and see what happens, but don't blame anyone if you crash. And an advice, never use higher gear when rolling down the hill, change to lower gear before rolling down, it's common sense.

Uhh sorry but no.

Compression braking is most certainly an effective way of maintaining a speed down a descent. As long as the tyres still maintain traction then the speed of the vehicle will be limited to what ever the current engine RPM is and the MPH per 1,000rpm the vehicles gearing provides.

This is a standard hill-descent technique when off roading, low ratio engaged, lower gera selected and feet off all the pedals and you do not accelerate down the hill at all but maintain a steady speed determined by the engine speed and the gearings MPH per Xrpm. One I've used many, many times before and certainly one that does not require the brakes to be used (in fact off road that' the very last thing you would do).