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

[Scaff]

You stack up poorly, and I'm getting sick of your constant harassment.

Do I really - care to explain why?

Oh and I haven't harassed you once, all I've done is ask you to explain your point of view in more detail.

Its quite straightforward, if you post you are effectively giving all members permission to quote you and reply. If you don't want that to happen then don't post, and it would be appreciated if you didn't abuse the report button again, once is enough.

GT5 > FM4 🤬, and I 🤬 if you agree or not, no one can 'prove' either game has superior physics.

If you bypass the swear filter one more time you will be getting an infraction, you will not be warned again.

We can't 100% prove the entire physics engine of any title, but we can look at selected elements and prove quite a bit, for example GT5 doesn't model full throttle launches correctly. That we can (and have) proven 100%.

I stand by that GT5 has no rivals on the PC.

Then expect to be asked to explain and provide evidence to back up your factual statement.

I have not got forza 4 unfortunately, will be getting it likely so can test out the zonda then, will probably just take a corner in 2nd holding it at mid revs, then foot down coming out of the corner and see what happens, corner will be sharp enough to push the tail out.

I will see if I get a chance to test this and put a video up for you, I know nothing beats giving it a go for yourself but it may be of interest. What you will also see when you get FM4 yourself is that the track in question is almost entirely high speed with nothing to really test the car in question in 2nd gear.

Scaff

 

[Spagetti69]

I'm guessing your talking about the alps.

Use the test track, various layouts on there for testing.

 

[Scaff]

Don't worry about giving your own details to public Scaff, I am not going to invade other's privacy just for the sake of a discussion in a forum. I acknowledge the good will on your part, and elaborating briefly about your job. That alone shows that you are true to your words:tup:.

I know that I might have been intrusive for being curious, please bear with me and I am really sorry if I any words that I posted earlier might have been uncomfortable for anyone to read.

No problem at all and it certainly didn't make me feel uncomfortable at all.

Now regarding GT5 and FM4, when I look at the replay of cars going in FM4, I get that weird feeling, the way the tires and the body the car moves while interacting with the road surface, it looked too busy - is there a word for this ? oh well, too sensitive to road surface ? While in GT5, the cars look so firmly grounded and less drastic movement, even on a low powered cars with soft suspension going in hard in a corner. These can be observed and compared on Top Gear Test Track, for example using De Lorean DMC, in which GT5 only has the standard car version.

Using stock cars with no mod, I did a couple of laps on both games, with the hand controller, GT5 car in cockpit and replay visually felt more firm and planted - weight transfer wise with less dive and suspension movement compared to FM4. In Forza 4, the Delorean DMC has that dive/squat during hard braking, exiting corner, and to certain degree suspension movement that visually gives impression that the road is bumpy on a smooth surface on Top Gear Test Track, this is more pronounced inside the cockpit view, but to my taste, is a bit too much. Maybe it's just me, or has anyone felt the same ? Any opinion is greatly appreciated ...

All I know about Delorean DMC is that it is a sports car, which surely has firmer spring and damper than most people mover like Corolla or Yaris.
Here are videos to see what I mean :

While I would agree that neither title gets this 100% right I would personally put FM4 ahead on this one.

The DMC-12 however is a tricky car to use for this kind of test much of which is to do with the car itself and its history. The DMC-12 was a poorly made car in its day and as such a lot of the cars that left the factory had to be rebuilt before being handed over to the customers (pretty much all the US stock had this happen) with changes being made to the cars at the time. Its also a car that has undergone serious owner modification over the years and we then have the problem that the car in GT5 and the car in FM4 are not the same.

GT5 use the S2 DMC-12 which is effectively an original car modified to bring it up to date and that included a range of suspension upgrades. The example in GT5 is from 2004. FM4 however models the original 1982 car. As you can imagine that makes direct comparisons very problematic.

Even looking at video footage causes its own issues, with this example:



Showing roll, dive and squat that are even more pronounced than the FM4 car.

Its also worth noting that a lot of modern hot hatches may well have firmer springs and dampers that most older 'sports' cars, as road cars go I personally think its an unpleasant change as while fine on track it can be a real pain on the road particularly if combined with low-profile tyres.

Based on my observation, FM4 seems to be a bit exaggerated in suspension movements or should I say amplified ? While in GT5, suspension movements are bit sterile, or lacking real world dynamics, that zig zag part on the real life video sums it up pretty well

While in overall terms I would agree with you I don't think the DMC-12 is a good car for the test (as outlined above), we should go for a more up to date car that features in both titles and allows a comprsion less likely to be confused by differing versions and owner modifications.

I would suggest something that's been on Top Gear as that means footage on a track that appears in both titles should be easy to find as well.

I'm guessing your talking about the alps.

Use the test track, various layouts on there for testing.

Yep it was the Alps, which is why the original comment was a bit of an overstatement by saidur_ali in my opinion, particularly when combined with it being the demo.

The TGTT is also a good bet for these kind of tests because it has a nice range of corners, in particular 2nd gear and also then allows back to backs with GT5 if required.


Scaff

 

[Spagetti69]

Ah the hammerhead.

Scaff, I've recently painted up a MK2 GT40(gulf)
Anyhow I was getting it into position for photographing and whilst I was doing this I revved the engine whilst in neutral and not moving.
From cockpit view the car is rocking side to side from shear engine power. I've never noticed this before. Probably happens on all high powered cars but it was the first time I noticed it.

Not sure if GT models this at all. Maybe.

 

[Scaff]

I have not got forza 4 unfortunately, will be getting it likely so can test out the zonda then, will probably just take a corner in 2nd holding it at mid revs, then foot down coming out of the corner and see what happens, corner will be sharp enough to push the tail out.

Here we go Zonda Cinque at the TGTT, same car as the demo and a 2nd gear corner, steady mid throttle to wide open and the back steps right out. Tyres were nice and warm as well as this was the third lap.

Ah the hammerhead.

Scaff, I've recently painted up a MK2 GT40(gulf)
Anyhow I was getting it into position for photographing and whilst I was doing this I revved the engine whilst in neutral and not moving.
From cockpit view the car is rocking side to side from shear engine power. I've never noticed this before. Probably happens on all high powered cars but it was the first time I noticed it.

Not sure if GT models this at all. Maybe.

FM has always had the cars rocking, annoyingly every damn car used to do it on the start grid in 1 to 3, even FWD runabouts, its now a lot more car sensitive.


Scaff

 

[BMWM52012]

Oh 80% of people on Gran Turismo Planet think that Gran Turismo physics are better than rival xbox360 exclusive Forza 4's physics. I'm sure 80% of people on Forza planet would also think GT's physics are better too. This thread must be an elaborate plot to find out who every Forza fanboy on this site is. Clever. I think GT5 feels much more realistic personally. Aside from the prototype car that generates enough G-force to easily kill its driver, and tops at 301 mph with stock everything.

 

[Patrick]

What feels more realistic? Tell us what. It's annoying seeing a lot of people just say "this game feels better".

 

[Cowboys965]

What feels more realistic? Tell us what.

Wait, so GT5 player is telling us how all Forza players think GT5 player is right, but also says GT5 player says GT5 is good because he's a GT5 player.

All GTs think GT is good because they are GTs.
I think GT is good.
All Forzytes think GT is good.

 

[Patrick]

Read the sentence I added.

 

[Cowboys965]

Oh 80% of people on Gran Turismo Planet think that Gran Turismo physics are better than rival xbox360 exclusive Forza 4's physics.

I think GT5 feels much more realistic personally.

My point.

 

[X-Power]

I personally, judging by the various evidence posted in this topic and my own experience of both games, think Forza 4 has the more realistic physics. They're not perfect, no game has perfect physics, but Forza 4's physics do seem to be closer to reality than GT5's physics. In Forza 4, each car handles like I would expect it to, old RWD muscle cars feel heavy and slow to respond, small modern FWD hot hatches feel light and responsive. The cars in Forza 4 are also more fun to drive, even cars like the Vauxhall Agila and Toyota Aygo are fun to thrash around a circuit. In comparison, GT5 just feels sterile and uninvolving. Judging by the evidence posted in this thread, GT5 has a very simplistic tyre model, whereas Forza 4 has a brilliant tyre model created with Pirelli tyre data. After playing FM4, GT5 just feels quite simplistic and sterile.

Before anyone calls me a "Forza fan"... I have played every Gran Turismo game except GTPSP and I am a fan of both Forza and Gran Turismo. In my opinion, PD need to improve the vehicle physics in Gran Turismo 6.

 

[TokoTurismo]

For me, I don't care which game is realistic or not realistic. As long as they have cars I'm happy... Btw, I own both games. Hot Wheels will say, "BEAT THAT!!!" That is all.

 

[evilserpentman]

I think the problem here is many people are mixing enjoyment with figures.

Scaff is talking about the facts, figures and the workings.

A lot of posters are talking about which is more fun, not neccesarily more 'correct'.

So, GT5 is more forgiving, hence it's possibly more widely recognised as more fun.
Forza is not quite as forgiving.

But, this is about facts here, not fun.

 

[TokoTurismo]

I think the problem here is many people are mixing enjoyment with figures.

Scaff is talking about the facts, figures and the workings.

A lot of posters are talking about which is more fun, not neccesarily more 'correct'.

So, GT5 is more forgiving, hence it's possibly more widely recognised as more fun.
Forza is not quite as forgiving.

But, this is about facts here, not fun.

Hmm. That's true. :/

 

[Patrick]

Oh 80% of people on Gran Turismo Planet think that Gran Turismo physics are better than rival xbox360 exclusive Forza 4's physics. I'm sure 80% of people on Forza planet would also think GT's physics are better too. This thread must be an elaborate plot to find out who every Forza fanboy on this site is. Clever.

Wrong.

 

[Lukeydopeyus]

While I would agree that neither title gets this 100% right I would personally put FM4 ahead on this one.

The DMC-12 however is a tricky car to use for this kind of test much of which is to do with the car itself and its history. The DMC-12 was a poorly made car in its day and as such a lot of the cars that left the factory had to be rebuilt before being handed over to the customers (pretty much all the US stock had this happen) with changes being made to the cars at the time. Its also a car that has undergone serious owner modification over the years and we then have the problem that the car in GT5 and the car in FM4 are not the same.

GT5 use the S2 DMC-12 which is effectively an original car modified to bring it up to date and that included a range of suspension upgrades. The example in GT5 is from 2004. FM4 however models the original 1982 car. As you can imagine that makes direct comparisons very problematic.

Even looking at video footage causes its own issues, with this example:



Showing roll, dive and squat that are even more pronounced than the FM4 car.

Its also worth noting that a lot of modern hot hatches may well have firmer springs and dampers that most older 'sports' cars, as road cars go I personally think its an unpleasant change as while fine on track it can be a real pain on the road particularly if combined with low-profile tyres.

While in overall terms I would agree with you I don't think the DMC-12 is a good car for the test (as outlined above), we should go for a more up to date car that features in both titles and allows a comprsion less likely to be confused by differing versions and owner modifications.

Scaff

Yeah, Scaff, you are right abut Delorean, they are different car in both games, I have found a video replay for Forza 4 with Nissan GTR SpecV, the car suspension looks a bit floaty at times - does not look like a 1700+kg car going at high speed. I see this on straights and high speed corner entry/exit.




Here is a video from Top Gear show, Nissan GTR 2012, not SpecV, but they are about the same, minor differences aside.




For GT5 ... Nissan GTR'07 not the same ...really



One more thing that I notice is the engine noise from inside the cockpit in both games, tried a stock Nissan R33 GTR Vspec 1997 on both games as I have been in the car in real life as a passenger and also drove it couple of times both stock and some modified ones - 400 kW of fun. Forza 4 sounds more accurate, while GT5 lacks the sound detail.

There's more though, the noise level inside the cabin in real life is not that loud, engine noise, exhaust noise are all too loud in FM4, while in GT5 sound levels are about right, although both lack the turbo noise, exhaust drone, valvetrain noises on idle to name a few. In my opinion, the sound effects inside cabin in FM4 are more accurate, but way too loud to my taste as most cars IRL have a well insulated cabin, while in FM4, even on unmodified car, the noise is almost like a stripped down interior car. For reference here is a video from Best Motoring race at Tsukuba with stock cars :





FM4 sound designers might have done this to thrill the players with stylishly accurate sound effect, whereas in GT5, the sound levels are geared toward realistic levels but alas they forgot how accurate it should be on most cars ...

 

[Scaff]

Yeah, Scaff, you are right abut Delorean, they are different car in both games, I have found a video replay for Forza 4 with Nissan GTR SpecV, the car suspension looks a bit floaty at times - does not look like a 1700+kg car going at high speed. I see this on straights and high speed corner entry/exit.



Here is a video from Top Gear show, Nissan GTR 2012, not SpecV, but they are about the same, minor differences aside.



For GT5 ... Nissan GTR'07 not the same ...really

Again its a tricky one because its not the exact same car in each and the GT5 clip is more in-car and menus than anything else.

The FM4 does look a like floaty but its not a million miles away at all, from the small amount of GT5 footage it looks too stiff with minimal roll and heave. Particularly given that the '12 GTR has a stiffer chassis and revised suspension (and I doubt they lowered the rates).

Still looking for that car to run....

One more thing that I notice is the engine noise from inside the cockpit in both games, tried a stock Nissan R33 GTR Vspec 1997 on both games as I have been in the car in real life as a passenger and also drove it couple of times both stock and some modified ones - 400 kW of fun. Forza 4 sounds more accurate, while GT5 lacks the sound detail.

There's more though, the noise level inside the cabin in real life is not that loud, engine noise, exhaust noise are all too loud in FM4, while in GT5 sound levels are about right, although both lack the turbo noise, exhaust drone, valvetrain noises on idle to name a few. In my opinion, the sound effects inside cabin in FM4 are more accurate, but way too loud to my taste as most cars IRL have a well insulated cabin, while in FM4, even on unmodified car, the noise is almost like a stripped down interior car. For reference here is a video from Best Motoring race at Tsukuba with stock cars :


FM4 sound designers might have done this to thrill the players with stylishly accurate sound effect, whereas in GT5, the sound levels are geared toward realistic levels but alas they forgot how accurate it should be on most cars ...

It's a bit of an off-topic but.....

No doubt that FM4 sounds are tweaked to make them a little more dramatic, FM4 does this to a much lower level that the rest of the series and given that T10 are hampered massively by the limits of Dolby Digital (the best your going to get out of the 360 via 5.1) I think they do a damn good job.

PD have the tools available in 7.1 LPCM from the PS3 to do the job and they make pretty good use of it for doppler effects and sound placement of other cars, however the recordings they use (and re-use between cars) disappoint far more that they please. A few cars sound good but they are few, most sound plain wrong. Some sound good at idle and very low revs (Shelby Cobra) but everything goes wrong as the revs rise, almost as if they were only able to capture the car at idle and concocted the rest of the sound. Most sound as if they were not recorded under load, simply done with the car in neutral and then just rev'd the hell out of it.


Scaff

 

[Sputnik]

I only played FM3 for a few weeks and it was terrible compared to GT5! Arcade!

 

[C_Raccoon23]

I only played FM3 for a few weeks and it was terrible compared to GT5! Arcade!

This is about Forza 4 though.

 

[Lukeydopeyus]

Here is hoping that the next GT5 update will be a massive overhaul of the physics engine, I know PD have the resources, and Kazunori Yamauchi must have known the issue of the current physics engine used, and he must have received so many input and complaints from various people - like us, if he ever read our forum ...

The first major issues to address are tire simulation, deformation, tire surface patch sizes, tire pressure, tire temperature and tire friction.Afterwards, PD can improve the current physics to better simulate weight shift + distribution ( driver's weight also included ), suspension-drivetrain( multi link, leaf spring, McPherson strut, double wishbone,torsion beam, live axle, 4wd transaxle, CV joints) and they need to make sure all settings accurate to real life counterpart, unlike now that all have .20 rear toe and 0.0 front toe

The engine power loss due to aerodynamic drag at speed, PD need to fix this as well, I've seen low power cars that in real life could not reach the top speed that can be achieved in GT5 when stock, and yet in GT5 the car could go over the safe engine rev limit as if there's no wind resistance, but road elevation seems to affect to some degree.

The clutch .... please allow manual clutch operation with DS3, just like TOCA used, I'd played TOCA 2 and 3, they were great with manual clutch 👍, blipping throttle on down shift feels like doing heel and toe in real life, which i always love to do in my own car when driving fast Don't forget also engine load simulation on drive train during down shift or up shift ( clutch slip) and engine stall - need to map a new button for engine starter, this will need proper clutch modelling, unlike the current one, which some says the clutch isn't like a clutch but a switch with some travel.

The last one, PD need to remove all assists, including the hidden steering assist when using DS3 in certain condition, I never played with ABS, or any other assist, but at times - sliding, loss of traction on trackside, or brake locks skid, the steering somehow altered by the game, to help me control the car .... I don't want that, in real car there's no such thing They can make this a pro simulation mode for DS3 under options ...

Enough of me ranting about GT5, Forza 4 by far have less to rant about beside the occasional awkward car movement during external view/replay and engine sound effects that are too loud. All I can say Forza 4 has found the nice spot for physics engine that can satisfy most racing fan on console, while GT5 needs more work, keep updating Kaz

 

[BMWM52012]

Wait, so GT5 player is telling us how all Forza players think GT5 player is right, but also says GT5 player says GT5 is good because he's a GT5 player.

All GTs think GT is good because they are GTs.
I think GT is good.
All Forzytes think GT is good.

I guess the sarcasm didn't carry. I was saying that members of a website devoted to a certain game are probably not going to favor a rival game over their own.

 

[Scaff]

I guess the sarcasm didn't carry. I was saying that members of a website devoted to a certain game are probably not going to favor a rival game over their own.

Don't always count on it. Quite a few of us are long serving member of GTP (I joined in 2003) but would class ourselves as more motorsport, car and racing/driving sim fans that GT fans.

As such we are interesting mainly it whatever title(s) offer us the best experience across those interests rather than sticking to a single series as a matter of dogma.

GT may have brought a lot here but most stay for far more than that.

Right now FM4 is top of my pile on consule becasue it offers me what I need; should an update for GT5 or GT6 arrive or Project CARS, etc, etc and they change that, well then that will become my focus.

I'm here for the cars and the physics, doesn't matter what name is on the box.


Scaff

 

[thelvynau]

I guess the sarcasm didn't carry. I was saying that members of a website devoted to a certain game are probably not going to favor a rival game over their own.

I love gt5 but I do prefer the other game over gt5 not by much.

Its not just fan boys on these forums or on forza planet.

 

[avens]

Here is hoping that the next GT5 update will be a massive overhaul of the physics engine, I know PD have the resources, and Kazunori Yamauchi must have known the issue of the current physics engine used, and he must have received so many input and complaints from various people - like us, if he ever read our forum ...

The first major issues to address are tire simulation, deformation, tire surface patch sizes, tire pressure, tire temperature and tire friction.Afterwards, PD can improve the current physics to better simulate weight shift + distribution ( driver's weight also included ), suspension-drivetrain( multi link, leaf spring, McPherson strut, double wishbone,torsion beam, live axle, 4wd transaxle, CV joints) and they need to make sure all settings accurate to real life counterpart, unlike now that all have .20 rear toe and 0.0 front toe

The engine power loss due to aerodynamic drag at speed, PD need to fix this as well, I've seen low power cars that in real life could not reach the top speed that can be achieved in GT5 when stock, and yet in GT5 the car could go over the safe engine rev limit as if there's no wind resistance, but road elevation seems to affect to some degree.

The clutch .... please allow manual clutch operation with DS3, just like TOCA used, I'd played TOCA 2 and 3, they were great with manual clutch 👍, blipping throttle on down shift feels like doing heel and toe in real life, which i always love to do in my own car when driving fast Don't forget also engine load simulation on drive train during down shift or up shift ( clutch slip) and engine stall - need to map a new button for engine starter, this will need proper clutch modelling, unlike the current one, which some says the clutch isn't like a clutch but a switch with some travel.

The last one, PD need to remove all assists, including the hidden steering assist when using DS3 in certain condition, I never played with ABS, or any other assist, but at times - sliding, loss of traction on trackside, or brake locks skid, the steering somehow altered by the game, to help me control the car .... I don't want that, in real car there's no such thing They can make this a pro simulation mode for DS3 under options ...

Enough of me ranting about GT5, Forza 4 by far have less to rant about beside the occasional awkward car movement during external view/replay and engine sound effects that are too loud. All I can say Forza 4 has found the nice spot for physics engine that can satisfy most racing fan on console, while GT5 needs more work, keep updating Kaz

that can't be done in an update. Also the current physics engine is more or less correct, thing is it doesn't simulate several elements like some that you mentioned.

And all that requires lots of time. LFS has like a 3-4 years delay working in only one of those aspects.

TOCA isn't a great example though. That's always been on the "simcade" part of this genre. By that time GTR2 was and still is miles better.

 

[Lukeydopeyus]

that can't be done in an update. Also the current physics engine is more or less correct, thing is it doesn't simulate several elements like some that you mentioned.

And all that requires lots of time. LFS has like a 3-4 years delay working in only one of those aspects.

TOCA isn't a great example though. That's always been on the "simcade" part of this genre. By that time GTR2 was and still is miles better.

I realized now I'm asking too much for a console game, I used to play Grand Prix 3 and Nascar 2003 on PC, they were great at the time. I always thought that simulation physics in GT5 are handled in game engine the way the PC game does ... not much that I know of, just guessing if they are to rebuild the physics to incorporate some of the things I mentioned, what would it take ... replace some system files in the game ?
At the very least, PD can take notes from PC sims like Iracing, LFS, GTR2, rFactor and many others, or even maybe get their physics engine as a reference

PS3 should have the computational power to do those number crunching, but now I'm left to wonder if Kazunori Yamauchi deliberately choose to leave out certain aspect of the physics engine for fears that the consumers might not like the game if it has a dedicated physics engine focused toward realism, like Iracing, which is only a portion of GT5 market size. Consoles market always have been handled differently than PC market ... market demography, hardware limitations and commercial reasons, just to name a few...

How many people would buy GT5 if it has Iracing physics or how many people would buy Iracing game released in consoles ? Not the same number like what GT5 have sold right now I' am afraid. PD must have thought that only a fraction of their consumer are serious fan of racing and willing to play a realistic simulator, because as we all know that PS3 owners and players are spread to a broad spectrum of age, interests and budget.

PD should listen to loyal fans like us from GTPlanet, and maybe GT6 would at least have all the aspects of physics that I have mentioned to justify it's claim as the real driving simulator.

You got me wrong Avens, I was not referring to TOCA physics at all, but rather it's implementation of clutch on hand controller to give the players with DS3 the same freedom similar to the wheels users when changing gears. By the way, I have this insane idea, what if Sony release a wireless clutch pedal device designed to work in tandem with DS3, so we can use our left foot for the clutch while we play with the DS3. I'm imagining myself doing it for some time while actually playing GT5, it might work well, who knows ...

 

[Samus]

Forgive me if this has already been mentioned but I don't really feel like reading 29 pages. But what about the aerodynamic physics of the game, and in particular drag and slipstreaming? I'm not talking about the basic slipstream model but how in GT5 many, many cars can reach 300mph+ simply by creating a slipstream 'chain' which to me with my basic understanding of physics isn't realistic all. I've not seen this sort of behaviour in Forza games so thoughts from people who probably have a better understanding than I do?

 

[Lukeydopeyus]

Forgive me if this has already been mentioned but I don't really feel like reading 29 pages. But what about the aerodynamic physics of the game, and in particular drag and slipstreaming? I'm not talking about the basic slipstream model but how in GT5 many, many cars can reach 300mph+ simply by creating a slipstream 'chain' which to me with my basic understanding of physics isn't realistic all. I've not seen this sort of behaviour in Forza games so thoughts from people who probably have a better understanding than I do?

I read this article a while ago, if human strength alone can do wonders when the aerodynamic drag is almost non existent or gone, then cars with more than 300mph top speed while slipstreaming is plausible, if it has enough hp and low enough weight, I say it might do it.

Here is the link

http://sportsillustrated.cnn.com/vault/article/magazine/MAG1119704/index.htm

The guy is pedaling a bicycle to a top speed of 150 mph, he was helped by means of slipstreaming a car in front of him, amazing isn't as this was done in 1985 ...👍

 

[Scaff]

I read this article a while ago, if human strength alone can do wonders when the aerodynamic drag is almost non existent or gone, then cars with more than 300mph top speed while slipstreaming is plausible, if it has enough hp and low enough weight, I say it might do it.

Here is the link

http://sportsillustrated.cnn.com/vault/article/magazine/MAG1119704/index.htm

The guy is pedaling a bicycle to a top speed of 150 mph, he was helped by means of slipstreaming a car in front of him, amazing isn't as this was done in 1985 ...👍

Enough HP is a must, but weight actually has little to do with it (weight is a factor in rolling resistance but that's about it), the drag co-ef of the car and its frontal area are much more important.

Power required = Total Resistance x Speed/375
Total Resistance = Air Resistance + Rolling Resistance

(Nice example of the full calculation from Famine here - https://www.gtplanet.net/forum/showthread.php?p=3354105)

That said neither title gets it right, but GT5 has some big issues (not that the FM4 ones are exactly small - just smaller) such as the daisy chain to reach improbable speed. Take the example you used of the bike, while an amazing feat it took a lead car capable of 300mph to achieve 150mph in the following vehicle by effectively removing most of the air resistance.

This kind of effect is correct but not to the degree GT allows it to be used, its not something I've seen happen in FM4.

The other issue I've found with GT5 (and to be fair I've not yet played around with this in FM4 - but do plan to) is the lack of lift on older cars.

Take something like the 1966 Ford GT40 MkII which generated lift at the following speeds:


1966 Ford GT40 MkII
Lift:
100 lbs. @ 150 mph, with 525 lbs. of drag
144 lbs. @ 180 mph, with 756 lbs. of drag
177 lbs. @ 200 mph, with 933 lbs. of drag
Source - http://www.mulsannescorner.com/aerodatabasefordgt4066.html

Which is frighting enough, but when they redesigned the car and the MkIV came along they had reduced the drag co-ef to achieve higher speeds along the various straights at Le Mans, however the effect on lift was just terrifying.

1967 Ford GT40 MkIV
Lift:
148 lbs. @ 150 mph, with 365 lbs. of drag
213 lbs. @ 180 mph, with 554 lbs. of drag
263 lbs. @ 200 mph, with 648 lbs. of drag
318 lbs. @ 220 mph, with 828 lbs. of drag


Given that it weighed 2,205lbs the lift was 14% at its top speed with reports of drivers being able to apply 1/4 turns lock in both directions on the Hunaudieres straight with no effect on the cars direction.

GT5 certainly doesn't recreate this and I have my doubts that FM4 does either. A quick look at the telemetry of FM4 will be able to let us know that one however, as the load on the front suspension should reduce as speed increases.

When I have some time this looks like a good area for testing.


Scaff

 

[thelvynau]

I just had a thought.

Say for example if gt5 or forza gets the physics 100% (for argument sake).

Would beginners be able to play it?

My guess is no game will attempt to simulate perfect physics because not everyone will derive enjoyment from it.

 

[hennessey86]

I know for a fact that most of you own PS3/PC wheels and you talk about forza 4 physics. I play both with a wheel and like scaff says both have there flaws but Forza is more realistic in my opinion.