Top Speed Physics

Scaff

Moderator
26,232
United Kingdom
He/Him
ScaffUK
ScaffGTP
The Collector's Edition. :D

It is unlikely to be easy to get good quality data and everything you need for all the cars in the game. Some games feel like you are actually just driving the data rather than a simulation. PDI's approach seems to be that of creating a perfect simulator. Although it is impossible, it gives plenty of scope to improve to become much closer to real. Even centuries later it will probably still be far from ideal. However you can still get good characteristics in a abstract way already and that level should improve greatly by over the next decade given improvements in CPU performance which will allow developers to express themselves better. Fortunately we still live in an era where we can still drive the real cars with combustion engines, if only it wasn't so costly compared to virtual.

Hamilton reached out to them, it is clear that he can drive quite well in the game straightaway so must be natural enough for him to adjust to. Also he can direct areas of the game to be better, read the setup of W08 will be improved. Great person for PDI to have on board given his experience with the real thing and bespoke F1 simulators and directing them to be more realistic. Also heard Toyota drivers which consist of F1 drivers in the past like Kobayashi and Alonso played GT Sport a lot while at Le Mans 2018. Good timing of the 1.19 update by PDI, played a part in Toyota's first Le Mans victory and 1-2.

I think in the future there may be cases that the GT engine will be used by F1 teams. Drivers themselves use GT Sport to practice and keep themselves sharp like Hamilton and Ocon. Nvidia used GT engine for self driving cars development so already a rival to rFactor Pro in that regard. Slowly but surely one day PDI will have all / most of the current F1 tracks in the game so should make GT a very attractive package having super realistic graphics (Good way to utilise their ray tracing system) and accuracy of tracks which is most realistic part of a sim. Teams would use their own data and likely physics model though as they know better in detail how everything works for their specific car which will likely be top secret information.

GT simulates wheel spin, probably if the physics engine ran at a faster rate and mapping was changed a little bit it would be easier to modulate even with current model. Longitudinal grip exists and is plentiful, just need to have fine throttle control which is not necessarily a bad thing for a simulator to teach a driver. It is quite satisfying nailing traction out of a corner unlike a lot of other sims where there is little skill involved. LFS is probably more of an arcade game than Driveclub, it has a lot less advanced physics engine either way. Passable back in 2003 though as a sim. Then you have more complex sim like rFactor 2 and they seemed to have simulated a black hole in their tyre model the way cars seem to slide instead of losing control as one would expect when you overcook a corner too much.

Aero like I said before is where I think GT is ahead of all PC sims regarding physics. It must be quite taxing having such an advanced system in the game with such a low end CPU that already has to process so much in the game such as the graphics and sound simulation. Cars feel like on the knife-edge at the aerodynamic limits which is fun unlike how dull it is in AC. Also your description of ACC aero model is actually the way they did it for AC regarding wings IIRC which was terrible. ACC is like GTS approach but seems a lot less advanced. The effect in driving is very much like AC though, they seemed to have retained that concrete rear end feeling of AC while driving but any sort of big suspension movement even at really low speed, it is almost like someone is performing a pit manoeuvre. :lol: It is quite similar to how it is in the F1 games. The cars still feel like they aren't under any aerodynamic load so doesn't surprise me that it seems braking technique is of that of a street car unlike GT Sport. Low speed physics in ACC does not feel right but they seem more like they are trying to simulate it unlike AC. Does not feel fun to drive but still a bargain for number of good quality tracks you get.

They exist and people use them on GT Sport already but what I had in mind was getting it so that it is mainstream. If the DS5 and next Logitech and Thrustmaster wheels have it then that is massive improvement in realism. PS4 isn't a great platform for FFB due to latency and low CPU performance not allowing for more complex physics to run at a decent frequency. Feedback will massively improve with GT with better hardware as they seem to have the realistic approach regarding FFB. Older wheels used to work good in older GTs but now it seems like almost a no compromise approach regarding force feedback that requires the wheel to be able to have the dynamic range and response with platform to give a realistic feeling. AC FFB feels quite amplified, you can feel it even on controller like Xbox 360.
So much of this is demonstrably untrue, PD have moved their physics game along to the point its reasonable. However the damper, aero and tyre model still lag behind.

Aero loading in particular has some clear issues.



F1 teams will never use GT as a platform, and if you look at motorsports grade simulations visuals are way down the priority list, and the likes of Ferrari, Mercedes and Porsche went in a different direction for experience centre simulators.

GT is great fun, but it's not a match for the likes of AC or even PC2 in terms of physics, and that's a quite clear design choice on PDs part.

GTS issues with load transfer can be experienced by doing back to backs quite easily, simply take the original Fiat 500 out around a track induce heavy understeer and then lift off the throttle sharply. In GTS you will simply slow down the degree that you are washing out, what should happen (in a stupidly light, shortwheel base, RR engined car with all its weight at the rear) is a rapid transition to lift off oversteer, and heavy lift off oversteer at that. AC models this very, very well.

Its the same with race prep'd FWD cars (and some road ones as well), GTS gives you a decrease in understeer when you lift off, when it should be a rapid transition to liftoff oversteer. Add in the lack of aggression from the diffs you have on these cars and in reality you should be able to lift off to get the back out, point in the right direction and hammer the throttle to drag the car around. which is exactly how they are driven in reality, and exactly how you drive them in AC and PC2, yet it simply doesn't work in GTS (and no amount of tuning of the cars will make it happen either).

Oh and the magic FFB with the TGT, it's a tactile Puck that's fed by GTS added into the wheel. You can get a better range of tactile feedback, across more titles, for less money with a standalone tactile setup (and if real accuracy in this regard is your end goal then simvibe on PC wipes the floor with it).

However once again it easy to experience the difference in FFB between GTS and other titles. Take any car to Brands Hatch (either layout) and end the first turn at a reasonable speed. Paddock Hill has a pronounced drop off, and the car on the racing line is not running parallel to the road. As such you should be able, through the FFB, to feel the left and right wheels load and unload, and it should be subtle enough that you can keep it under control simply by changing the amount of pressure in your wrists very slightly. Once again you get this in both PC2 and AC (with AC being better in this regard), GTS you get nothing at all.

Now don't get me wrong, I'm in a place that I really, really like GTS; but I'm also quite aware of the limits it has in regard to its physics engine and tyre model.
 
Last edited:
2,754
United States
Theresa, Wisconsin
F1 teams will never use GT as a platform, and if you look at motorsports grade simulations visuals are way down the priority list, and the likes of Ferrari, Mercedes and Porsche went in a different direction for experience centre simulators.

:confused::confused: Wait a minute, do you mean if I were to spend millions on an F1 simulator that it would not include a livery editor???:D:D:cheers:
 

Scaff

Moderator
26,232
United Kingdom
He/Him
ScaffUK
ScaffGTP
Seems to be the case, at least in GT land. Of course, the faster you go, the more air passes through the radiator which I imagine would cancel out the higher air temp (if it's modelled in GT, which I seriously doubt).

IIRC the difference in temp between hottest time and coolest at SSRX is only ~5 degrees C, so I imagine the effect of density is more important at those speeds than the loss of engine hp. Also we are only talking 2-3 km/h difference here at speeds >600 km/h, so it's not a huge difference :lol: But if you're going for the ultimate record, every little thing helps - set toe/camber to zero, car wash, etc.

It would be interesting to see what the real world calculations is like for air density vs temp, but I don't have a brain big enough to do that :P



If you want to be pedantic, it's a "simplification that creates fundamental flaws at extreme situations". Though of course, no sim is perfect (and likely never will be, or we'll be creating a parallel universe inside our own) and even ACC is bound to get it wrong if you set values beyond reasonable parameters. But GT's known aero/top speed issues has plagued the series since GT1, and PD/Kaz does not show any intention of rectifying it, despite saying with every new release that the aero model has been revamped.

I'm pretty certain ACC is the only sim to put ride height under Aero settings, but this doesn't mean other hardcore sims (rF2, PCARS, iRacing, RRRE, LFS) doesn't model them. Kunos just wants emphasis on how sensitive GT3 cars are to rake so that's why they designed the UI that way.

Interesting results on the Tomahawk. Though as I said above, the difference in GT6 was tiny (2-3 km/h @ >600 km/h) and that was with DRS (which you can't do in GTS currently) and between time 15:30 and just before dawn (which is not selectable in GTS). So possibly the difference is still there but we can't replicate the conditions in GTS. Or PD could just not model air density anymore *shrugs*.
I can confirm that aero and ride height are certainly modelled in PC2, I've tested it and thanks to the real time telemetry you can see cars that generate lift gaining ride height as speed increases and those that generate downforce reducing in ride height.

The degree varies depending on the car, aero and aero setup, but its clearly modelled and can generate enough to bottom the suspension out.
 

LeGeNd-1

Premium
6,757
Australia
Australia
GTP_LeGeNd-1
I can confirm that aero and ride height are certainly modelled in PC2, I've tested it and thanks to the real time telemetry you can see cars that generate lift gaining ride height as speed increases and those that generate downforce reducing in ride height.

The degree varies depending on the car, aero and aero setup, but its clearly modelled and can generate enough to bottom the suspension out.

That is really cool. Not enough games feature detailed telemetry these days. I still remember poring over the telemetry in EA Sports (yes, that EA) F1 2002 and spending hours correlating the graphs with setup and trying to get that last few tenth. GT6 had a crude telemetry which was a good start, god knows why they decide to remove it in GTS which is supposed to be heavy on the competitive aspect.
 

Scaff

Moderator
26,232
United Kingdom
He/Him
ScaffUK
ScaffGTP
That is really cool. Not enough games feature detailed telemetry these days. I still remember poring over the telemetry in EA Sports (yes, that EA) F1 2002 and spending hours correlating the graphs with setup and trying to get that last few tenth. GT6 had a crude telemetry which was a good start, god knows why they decide to remove it in GTS which is supposed to be heavy on the competitive aspect.
I've recorded some testing with it, once I get a chance to get the video edited I will link it here.
 
6,573
United Kingdom
United Kingdom
Collector Edition here too.

Well mate, I think you must be living in a parallel universe then. There is so many things wrong with your text here I'm not even gonna bother correcting them all, as I suspect you're one of those people who thinks GT>>>>>all and no amount of rational argument is going to convince you. So let's agree to disagree here :)
GT is the real driving simulator, it says so on the box so it must be true. :)

In all seriousness, GT does so much better than PC sims in a lot of areas. It is good to see Alan rate GT highly based on a real world driving experience.

So much of this is demonstrably untrue, PD have moved their physics game along to the point its reasonable. However the damper, aero and tyre model still lag behind.

Aero loading in particular has some clear issues.



F1 teams will never use GT as a platform, and if you look at motorsports grade simulations visuals are way down the priority list, and the likes of Ferrari, Mercedes and Porsche went in a different direction for experience centre simulators.

GT is great fun, but it's not a match for the likes of AC or even PC2 in terms of physics, and that's a quite clear design choice on PDs part.

GTS issues with load transfer can be experienced by doing back to backs quite easily, simply take the original Fiat 500 out around a track induce heavy understeer and then lift off the throttle sharply. In GTS you will simply slow down the degree that you are washing out, what should happen (in a stupidly light, shortwheel base, RR engined car with all its weight at the rear) is a rapid transition to lift off oversteer, and heavy lift off oversteer at that. AC models this very, very well.

Its the same with race prep'd FWD cars (and some road ones as well), GTS gives you a decrease in understeer when you lift off, when it should be a rapid transition to liftoff oversteer. Add in the lack of aggression from the diffs you have on these cars and in reality you should be able to lift off to get the back out, point in the right direction and hammer the throttle to drag the car around. which is exactly how they are driven in reality, and exactly how you drive them in AC and PC2, yet it simply doesn't work in GTS (and no amount of tuning of the cars will make it happen either).

Oh and the magic FFB with the TGT, it's a tactile Puck that's fed by GTS added into the wheel. You can get a better range of tactile feedback, across more titles, for less money with a standalone tactile setup (and if real accuracy in this regard is your end goal then simvibe on PC wipes the floor with it).

However once again it easy to experience the difference in FFB between GTS and other titles. Take any car to Brands Hatch (either layout) and end the first turn at a reasonable speed. Paddock Hill has a pronounced drop off, and the car on the racing line is not running parallel to the road. As such you should be able, through the FFB, to feel the left and right wheels load and unload, and it should be subtle enough that you can keep it under control simply by changing the amount of pressure in your wrists very slightly. Once again you get this in both PC2 and AC (with AC being better in this regard), GTS you get nothing at all.

Now don't get me wrong, I'm in a place that I really, really like GTS; but I'm also quite aware of the limits it has in regard to its physics engine and tyre model.
Aero in GTS is far ahead of AC IMO, I actually haven't yet bought the Ferrari F1 DLC on PC because of how terrible aero simulation is in AC. Even pCARS 2 does it better than AC but to be fair, AC is quite old. I might buy the Ultimate Edition on PS4 and demonstrate how much worse the aero is in AC than GT.

Quite a number of F1 teams and car manufacturers use rFactor Pro. It could be a good way to gain revenue for PDI. There should be quite beastly CPUs and GPUs next year on the 7nm EUV node so should be able to still match display refresh rates, perfect time for F1 teams to upgrade and GT should be a great software upgrade if Sony and PDI offer it to them that is. VR also should be more viable to utilise due to increase of resolution. I would be surprised if it doesn't happen within the next decade. It does not surprise me that Lewis uses GTS more to practice than the Mercedes simulator as that one does look like a "very bad computer game" to me also.
Mercedes F1 Simulator.png
Kind of looking forward to see how PDI might be involved in the next GT-R too and great to see Toyota getting involved with GTS.

GT suspension doesn't really do much movement and also tyre temperatures seem simplified in the game so you also likely won't get effect of lower rear tyre temperatures on FWD cars. Kind of feels like placeholder level making the game more accessible plus only so much you can do with a processor that is slower than an Intel Atom CPU or even the Cell CPU at some tasks, next console should be at least 4X improvement and at Intel Core i9 level of performance which opens up possibility of doing so much more in terms of physics. Also would be great if they do damage modelling realistically like the crumpling effect, would make racing more realistic. I think they've done a great job in getting the right kind of driving style for majority of cars in the game, a big improvement over GT6. Now it is possible to hold steering angle through a corner, it is important to steer and lean on the front tyres and utilise the downforce by keeping car stable while in GT6 it was more driving with the rear. Also breaking traction is penalised much more in GTS.

I think in AC, everything turns to understeer quite quickly. So even if you lift off and get oversteer, it is very hard to lose control of car even being super aggressive with the inputs, it will still quickly turn to understeer on power. I think iRacing does suspension and feeling like there is a consequence for bad driving much better than any other PC simulator game.

I haven't used T-GT, I was getting at they are trying to do FFB realistically on what is actually felt and separating things. I wonder though if the T-GT GT mode is an experiment outside of standard USB HID class for better FFB potential.

Last time I drove Brands Hatch on GT with a wheel was at the Copper Box Arena and can't remember how it was. Don't have PS4 with me at the moment so might be a while before I can test properly as ideally I would want to get / try on a direct drive wheel to see what current level of FFB is really at as belt wheels ruin a lot of subtle feedback plus they don't have the range to replicate the forces well enough. This person thinks it is realistic.


Also notice Matt Prior seems to rate handling of the game quite highly: Link


I agree that there is a lot of limits regarding its physics engine which is why I don't really play it much although I must say the championships they are offering are really tempting. I'm really waiting on PS5 and I might get back into racing games if level is really good, hopefully see next GT this year on PS5 being shown off.

That is really cool. Not enough games feature detailed telemetry these days. I still remember poring over the telemetry in EA Sports (yes, that EA) F1 2002 and spending hours correlating the graphs with setup and trying to get that last few tenth. GT6 had a crude telemetry which was a good start, god knows why they decide to remove it in GTS which is supposed to be heavy on the competitive aspect.
Probably the most realistic official F1 game still, amazing to think that engine would develop into what is widely used by car manufacturers and F1 teams.
 

Scaff

Moderator
26,232
United Kingdom
He/Him
ScaffUK
ScaffGTP
GT is the real driving simulator, it says so on the box so it must be true. :)

In all seriousness, GT does so much better than PC sims in a lot of areas. It is good to see Alan rate GT highly based on a real world driving experience.

I have a youtube channel and a great degree of real world driving experience, I disagree with that.


Aero in GTS is far ahead of AC IMO, I actually haven't yet bought the Ferrari F1 DLC on PC because of how terrible aero simulation is in AC. Even pCARS 2 does it better than AC but to be fair, AC is quite old. I might buy the Ultimate Edition on PS4 and demonstrate how much worse the aero is in AC than GT.
You keep saying this, yet have no experience with the vehicle in question in AC and have provided nothing at all to back up your claim.

The only point I would agree on here is that PC2 does a better job in aero.

Quite a number of F1 teams and car manufacturers use rFactor Pro. It could be a good way to gain revenue for PDI. There should be quite beastly CPUs and GPUs next year on the 7nm EUV node so should be able to still match display refresh rates, perfect time for F1 teams to upgrade and GT should be a great software upgrade if Sony and PDI offer it to them that is. VR also should be more viable to utilise due to increase of resolution. I would be surprised if it doesn't happen within the next decade.
You are seriously clutching at straws with this, RFactor Pro, AC Pro and PCPro are all used by manufacturers and teams right now, you will notice that GT isn't in that list, and given the limitations that PD still have with GTS they are a long way off getting to that point.


It does not surprise me that Lewis uses GTS more to practice than the Mercedes simulator as that one does look like a "very bad computer game" to me also.
View attachment 808744
Kind of looking forward to see how PDI might be involved in the next GT-R too and great to see Toyota getting involved with GTS.
You do know that all of the above is pretty much 100% marketing?


GT suspension doesn't really do much movement and also tyre temperatures seem simplified in the game so you also likely won't get effect of lower rear tyre temperatures on FWD cars.
Yet its the sim that all the race teams and manufacturers should be using?

Kind of feels like placeholder level making the game more accessible plus only so much you can do with a processor that is slower than an Intel Atom CPU or even the Cell CPU at some tasks, next console should be at least 4X improvement and at Intel Core i9 level of performance which opens up possibility of doing so much more in terms of physics.
Ah the old PS4 isn't powerful enough argument.

Its actually far more straightforward than that, PD focus on the visual aspect of its titles over the simulation, they always have doe so. Its really quite obvious to pretty much everyone apart from the GT apologists.


Also would be great if they do damage modelling realistically like the crumpling effect, would make racing more realistic. I think they've done a great job in getting the right kind of driving style for majority of cars in the game, a big improvement over GT6. Now it is possible to hold steering angle through a corner, it is important to steer and lean on the front tyres and utilise the downforce by keeping car stable while in GT6 it was more driving with the rear. Also breaking traction is penalised much more in GTS.
I agree that GTS has improved things, teh problem for PD is that so has the rest of the genre.


I think in AC, everything turns to understeer quite quickly.
Road cars I would agree, just as they do in reality. Race spec cars, well that depends on exactly how you tune them.

So even if you lift off and get oversteer, it is very hard to lose control of car even being super aggressive with the inputs, it will still quickly turn to understeer on power.
It really, really doesn't.

I think iRacing does suspension and feeling like there is a consequence for bad driving much better than any other PC simulator game.
I personally think iRacing still has issues with its tyre model that unfortunately hamper it in that regard, however that doesn't stop PD being behind the curve still in this area.


I haven't used T-GT, I was getting at they are trying to do FFB realistically on what is actually felt and separating things. I wonder though if the T-GT GT mode is an experiment outside of standard USB HID class for better FFB potential.
I know, and as I explained better and cheaper ways of getting the same exist for any rig.


Last time I drove Brands Hatch on GT with a wheel was at the Copper Box Arena and can't remember how it was. Don't have PS4 with me at the moment so might be a while before I can test properly as ideally I would want to get / try on a direct drive wheel to see what current level of FFB is really at as belt wheels ruin a lot of subtle feedback plus they don't have the range to replicate the forces well enough. This person thinks it is realistic.
I can, because the last time I drove all three with a wheel was yesterday.


This person thinks it is realistic.

Also notice Matt Prior seems to rate handling of the game quite highly: Link

Would you like me to provide a list of people on the internet saying the exact same thing about every title in the genre?

That's aside from the fact you forgot that neither of those sources actually says what you claim they do, and the first one isn't even addressing the point I made.

I agree that there is a lot of limits regarding its physics engine which is why I don't really play it much although I must say the championships they are offering are really tempting. I'm really waiting on PS5 and I might get back into racing games if level is really good, hopefully see next GT this year on PS5 being shown off.
And yet you continue to try and argue that its a better sim that just about anything and should be used by manufactures and teams!

Your now contradicting yourself massively.

What you actually seem to be saying is that if GT overhauled its tyre model, its suspension model and got rid of the "limits regarding its physics engine), oh and ran on a high end PC set-up then it would be the finest sim around and all the team and manufacturers would be using it.

That does however miss one rather key point, that's not what we have right now and isn't the product you are making the claims for unrivaled accuracy about.
 
Last edited:

CLowndes888

I want to be monkey
Premium
10,566
Australia
Melbourne
fubbletrouble888
Aero like I said before is where I think GT is ahead of all PC sims regarding physics. It must be quite taxing having such an advanced system in the game with such a low end CPU that already has to process so much in the game such as the graphics and sound simulation. Cars feel like on the knife-edge at the aerodynamic limits which is fun unlike how dull it is in AC. Also your description of ACC aero model is actually the way they did it for AC regarding wings IIRC which was terrible. ACC is like GTS approach but seems a lot less advanced. The effect in driving is very much like AC though, they seemed to have retained that concrete rear end feeling of AC while driving but any sort of big suspension movement even at really low speed, it is almost like someone is performing a pit manoeuvre. :lol: It is quite similar to how it is in the F1 games. The cars still feel like they aren't under any aerodynamic load so doesn't surprise me that it seems braking technique is of that of a street car unlike GT Sport. Low speed physics in ACC does not feel right but they seem more like they are trying to simulate it unlike AC. Does not feel fun to drive but still a bargain for number of good quality tracks you get.
I'm sorry, GT Sport has proved that it's aero is behind the PC sims. There isn't aero wash and no downforce is simulated underneath the car. It's all going over the top of the car which substantially throws the balance off; the game has to overcompensate for that. In the case of Project Cars 2, there is definitely underbody aero. The best comparison to make in order to understand this is by driving the La Ferrari. In GT Sport, you are constantly scrabbling for traction and braking is awful. In Project Cars 2, the car is much more grounded and has much better traction. Braking distances are shorter too. I know that the La Ferrari has a decent amount of aero underneath the car, not dissimilar to a race car. The only reason why GT3 cars are soo much easier to handle is because of the huge wings they have. The La Ferrari doesn't have that so it has to rely more on downforce being generated underneath the car. As GT Sport doesn't do this, it sits behind the PC sims.
 
2,754
United States
Theresa, Wisconsin
It does not surprise me that Lewis uses GTS more to practice than the Mercedes simulator as that one does look like a "very bad computer game" to me also.
.

You're saying that Hamilton uses GTS to practice F1 racing more than he uses the Merc F1 simulator? I dont believe that in the slightest, if he does play GTS it would simply be to "play". There is virtually nothing to be gained for his racing career by playing GTS, it does not simulate real driving near close enough. Not only that but he would be limited by tracks and car adjustability. He wouldn't even be able to adjust the most basic thing, tire air pressure in GTS.
 
373
Australia
Australia
wmd351
Does the Merc F1 simulator have Spa? :)

But on a serious note, did previous GT's use under car modelling for ground effects cars like the Chaparral or was it just added downforce trickery?
 

LeGeNd-1

Premium
6,757
Australia
Australia
GTP_LeGeNd-1
Scaff, I respect you for trying to educate Saidur, but I think for the sake of your time and sanity, just ignore him. The human mind has incredible capacity to block out objectivity once it decides to believe in something. You won't change his mind even after another 100 pages or arguing :lol:

I'm sorry, GT Sport has proved that it's aero is behind the PC sims. There isn't aero wash and no downforce is simulated underneath the car. It's all going over the top of the car which substantially throws the balance off; the game has to overcompensate for that. In the case of Project Cars 2, there is definitely underbody aero. The best comparison to make in order to understand this is by driving the La Ferrari. In GT Sport, you are constantly scrabbling for traction and braking is awful. In Project Cars 2, the car is much more grounded and has much better traction. Braking distances are shorter too. I know that the La Ferrari has a decent amount of aero underneath the car, not dissimilar to a race car. The only reason why GT3 cars are soo much easier to handle is because of the huge wings they have. The La Ferrari doesn't have that so it has to rely more on downforce being generated underneath the car. As GT Sport doesn't do this, it sits behind the PC sims.

Pretty much what I said on the first page of this thread. While I agree that underbody aero is inadequate in GT, I do think it's modelled. Just not strong enough to be significant in comparison to upper body aero. However...

But on a serious note, did previous GT's use under car modelling for ground effects cars like the Chaparral or was it just added downforce trickery?

You raised a good point. I actually looked up Chaparral 2J videos on YT and sure enough the settings screen showed downforce 0 0. But we all know how much grip the 2J has in comparison to other race cars. So I guess PD can add significant amounts of underbody downforce through the physics engine for special cases. Why they didn't do so for other race cars and supercars, who knows?
 

CLowndes888

I want to be monkey
Premium
10,566
Australia
Melbourne
fubbletrouble888
You raised a good point. I actually looked up Chaparral 2J videos on YT and sure enough the settings screen showed downforce 0 0. But we all know how much grip the 2J has in comparison to other race cars. So I guess PD can add significant amounts of underbody downforce through the physics engine for special cases. Why they didn't do so for other race cars and supercars, who knows?
The Chapparal is definitely an exception to the general trend.
 

LeGeNd-1

Premium
6,757
Australia
Australia
GTP_LeGeNd-1
*BUMP*

Someone hacked the game files and removed the excess downforce on the McLaren F1, and surprise surprise, it managed to reach its real life top speed (240-241 mph). Dunno why PD decides this car needs more DF, and the Vulcan/Veneno for example barely has any. But that's classic Kaz logic for you.


Also a video showing that downforce is possibly calculated directly from wheel speed (and not vehicle speed relative to the air). So aero modelling is probably even more wonkier than just wrong DF values :lol:


Thanks to @Whistle Snap for making these videos.
 
Last edited:
1,229
United States
California
JoshsoJB
*BUMP*

Someone hacked the game files and removed the excess downforce on the McLaren F1, and surprise surprise, it managed to reach its real life top speed (240-241 mph). Dunno why PD decides this car needs more DF, and the Vulcan/Veneno for example barely has any. But that's classic Kaz logic for you.


Also a video showing that downforce is possibly calculated directly from wheel speed (and not vehicle speed relative to the air). So aero modelling is probably even more wonkier than just wrong DF values :lol:


Thanks to @Whistle Snap for making these videos.
I've read that the McLaren F1 has a "high downforce mode" that's probably turned off during those 240mph runs. Knowing how off the top speeds are from the video above, it's probably just due to their aero model that it doesn't reach the irl speed but it's possible the one in GTS is in that mode. The top speeds of the other cars in that video (that aren't hitting the rev limiter) are consistently ~20mph higher than irl but that much lower in the F1's case, so that kind of supports the hdm theory. Its special slippery aerodynamics not being simulated could also be a thing though and it's just going how fast your standard light 600hp car with GTS's aero model would go. idk lots of possibilities, just throwing it out there that it has that mode.
 

LeGeNd-1

Premium
6,757
Australia
Australia
GTP_LeGeNd-1
I've read that the McLaren F1 has a "high downforce mode" that's probably turned off during those 240mph runs. Knowing how off the top speeds are from the video above, it's probably just due to their aero model that it doesn't reach the irl speed but it's possible the one in GTS is in that mode. The top speeds of the other cars in that video (that aren't hitting the rev limiter) are consistently ~20mph higher than irl but that much lower in the F1's case, so that kind of supports the hdm theory. Its special slippery aerodynamics not being simulated could also be a thing though and it's just going how fast your standard light 600hp car with GTS's aero model would go. idk lots of possibilities, just throwing it out there that it has that mode.

The McLaren F1 HDF mode is often exaggerated. What it does have are two small fans in the rear flanks of the car, which activates during braking to maintain air attachment to the diffuser. It only provides a very small increase in downforce, and the whole car itself doesn't produce much downforce/drag either. That's why it can reach 240 mph with "only" 627 HP whereas the Veyron needs 1001 HP to go just 14 mph faster.

Watch here from 18.50 onwards, straight from the man himself ;)

I've driven mods of McLaren F1 in AC, with properly made physics and everything, and it is very difficult to drive fast. PD probably thought it would be too difficult for the masses, and would damage the reputation of the F1 too much if they presented it realistically, so they added a lot of downforce to make it easier to drive.
 
5,815
Germany
Hanover/Germany
alexpkas
The McLaren F1 HDF mode is often exaggerated. What it does have are two small fans in the rear flanks of the car, which activates during braking to maintain air attachment to the diffuser. It only provides a very small increase in downforce, and the whole car itself doesn't produce much downforce/drag either. That's why it can reach 240 mph with "only" 627 HP whereas the Veyron needs 1001 HP to go just 14 mph faster.

Watch here from 18.50 onwards, straight from the man himself ;)

I've driven mods of McLaren F1 in AC, with properly made physics and everything, and it is very difficult to drive fast. PD probably thought it would be too difficult for the masses, and would damage the reputation of the F1 too much if they presented it realistically, so they added a lot of downforce to make it easier to drive.

PD just doesn't care too much about exact accuracy...