Top Speed Physics

6,573
United Kingdom
United Kingdom
As Scaff said, it's not a lack of torque or power, but the Mac hits an aerodynamic drag wall basically. IIRC the default gear ratios are also wrong on the F1, and especially the 6th gear is much longer than the actual car which further compounds the problem.
Personally I'm really impressed by the F1 car in GT Sport, seems one of the most realistic cars in the game. There are a lot of limitations caused by PS4 having low CPU power so I think they've done a great compromise between all aspects. Hopefully PS5 releases this year so PDI can start showing their true level. They will be in unique situation being probably only simulation racing game developer who can target really high minimum specs so I won't be surprised if they offer the best simulation given they have a lot of talented people at PDI.

 

LeGeNd-1

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Personally I'm really impressed by the F1 car in GT Sport, seems one of the most realistic cars in the game. There are a lot of limitations caused by PS4 having low CPU power so I think they've done a great compromise between all aspects. Hopefully PS5 releases this year so PDI can start showing their true level. They will be in unique situation being probably only simulation racing game developer who can target really high minimum specs so I won't be surprised if they offer the best simulation given they have a lot of talented people at PDI.


We were talking about the McLaren F1 road car, not the Merc F1 car. I think you got confused a bit there.

As for the Merc F1 itself, I have explained many times in other threads that it leaves a lot to be desired. Maybe the intrinsic physics are good, but the way the FFB communicates the physics is just terrible in my opinion and completely unnatural to drive fast, especially in slow speed corners. Compared to a similar vehicle in Assetto or Automobilista it's light years difference. Laptimes are not end all be all comparison and you really gotta drive this car in other sims to know the difference.

In general, due to the nature of GT and Forza games being simulations for "mass market" and containing lots of different variety of cars, their physics engine are tailored to suit the majority of vehicles (i.e. road cars of mid level performance). Hence cars at extremes of scale (F1, lightweights like Caterham, electric cars and hypercars with lots of fancy new tech) are not going to be simulated properly without a lot of fudging of numbers under the hood. The only sim that is truly jack of all trades is Assetto, but even that takes a truly talented modder that understands the physics engine inside out to fully take advantage of.
 
94
United States
United States
K32
That'd be the hybrid system finally running out of power. The P1 goes on a sort of low boost mode after reaching 7th (which is why you are able to maintain ~430 km/h) , but after a while the energy is eventually spent and the car relies entirely on pure horsepower to keep going (the reason why you can barely stay above 400 km/h) .

As you slowed down the brakes generated heat, which is recovered as energy by the McLaren's ERS system, thus giving you that boost to once again reach the same top speed after accelerating anew.

Simple.

Hope this clears that up for you.

This is so Polyphony Digital taking details to the extreme, man I love this company
 
6,573
United Kingdom
United Kingdom
We were talking about the McLaren F1 road car, not the Merc F1 car. I think you got confused a bit there.

As for the Merc F1 itself, I have explained many times in other threads that it leaves a lot to be desired. Maybe the intrinsic physics are good, but the way the FFB communicates the physics is just terrible in my opinion and completely unnatural to drive fast, especially in slow speed corners. Compared to a similar vehicle in Assetto or Automobilista it's light years difference. Laptimes are not end all be all comparison and you really gotta drive this car in other sims to know the difference.

In general, due to the nature of GT and Forza games being simulations for "mass market" and containing lots of different variety of cars, their physics engine are tailored to suit the majority of vehicles (i.e. road cars of mid level performance). Hence cars at extremes of scale (F1, lightweights like Caterham, electric cars and hypercars with lots of fancy new tech) are not going to be simulated properly without a lot of fudging of numbers under the hood. The only sim that is truly jack of all trades is Assetto, but even that takes a truly talented modder that understands the physics engine inside out to fully take advantage of.
Oops, saw you mention F1 and torque while skim reading, I see what you mean now. Someone should do a comparison between McLaren F1 GTS vs Real and see how it differs. More car data to correlate with and improvement of simulation should make it all closer. I think PDI are likely to have more clout to get access to more real life data too.

Anyway I think good to bring the W08 up being one of the more complex and recent additions to GT, you can see it is quite realistic in performance. I hope Lewis association with GT is long term and he can help improve GT by giving insights to PDI that only a driver of his calibre would know.

Feels natural enough for me to be fast with it although quite not there yet. I actually find low speed physics in GT Sport very promising for future games. They seem like they are trying to replicate it while most other sim games it doesn't feel like there are really any traction phases, you just mash the throttle and you get close to perfect traction.

Aero simulation is where I think physics of GT is strongest at the moment, can't think of another game better at the moment. I have driven most other sims and that makes me appreciate more how good GT is fundamentally, they really did a huge step going from GT6 to GTS and they are largely being held back by the CPU. They are smart with what they are working on this generation bringing tracks, cars, networking, UI / OS and sound up to a high level ready for next-generation and working on physics underpinnings that could make big step forward with more processing power, going like from 2D to 3D. PDI are usually at the cutting edge of tech and finally with PS5 they will have the platform to make "THE REAL DRIVING SIMULATOR". For long they might have been envious of hardware F1 teams have to develop simulators on but now it's going to be their turn to show their level.

I do hope with better connectivity standards and lower latency that PS5 should have, it opens up potential of a pressure sensitive L2 trigger. Also hopefully there will be more direct drive wheels and pedals with pressure sensitive brake pedal by then, that will make realism much better too.
 
The Corvette C7 impresses me the most: 460 hp and hits 340 Km/h (almost 370 going downhill). And this is stock! The maximum speed, stated by Chevrolet, is 195 Mph or 313 Km/h. I wonder if engine displacement also has some influence on these speeds.
 
10
United Kingdom
United Kingdom
How realistic are top speeds meant to be on GT Sport? I tested the Lamborghini Aventador and the top speed was similar to its real life top speed, but then I took the Aston Martin DB11 for a run and got to over 220MPH in a car which shouldn't be hitting speeds like that.
 

LeGeNd-1

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6,744
Australia
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GTP_LeGeNd-1
Oops, saw you mention F1 and torque while skim reading, I see what you mean now. Someone should do a comparison between McLaren F1 GTS vs Real and see how it differs. More car data to correlate with and improvement of simulation should make it all closer. I think PDI are likely to have more clout to get access to more real life data too.

Anyway I think good to bring the W08 up being one of the more complex and recent additions to GT, you can see it is quite realistic in performance. I hope Lewis association with GT is long term and he can help improve GT by giving insights to PDI that only a driver of his calibre would know.

Feels natural enough for me to be fast with it although quite not there yet. I actually find low speed physics in GT Sport very promising for future games. They seem like they are trying to replicate it while most other sim games it doesn't feel like there are really any traction phases, you just mash the throttle and you get close to perfect traction.

Aero simulation is where I think physics of GT is strongest at the moment, can't think of another game better at the moment. I have driven most other sims and that makes me appreciate more how good GT is fundamentally, they really did a huge step going from GT6 to GTS and they are largely being held back by the CPU. They are smart with what they are working on this generation bringing tracks, cars, networking, UI / OS and sound up to a high level ready for next-generation and working on physics underpinnings that could make big step forward with more processing power, going like from 2D to 3D. PDI are usually at the cutting edge of tech and finally with PS5 they will have the platform to make "THE REAL DRIVING SIMULATOR". For long they might have been envious of hardware F1 teams have to develop simulators on but now it's going to be their turn to show their level.

I do hope with better connectivity standards and lower latency that PS5 should have, it opens up potential of a pressure sensitive L2 trigger. Also hopefully there will be more direct drive wheels and pedals with pressure sensitive brake pedal by then, that will make realism much better too.

Well I don't know which version of GT Sport you're playing, but my impressions are all the opposite to yours.

Real life data doesn't mean anything if the game physics can't translate it properly. I'm pretty sure they have all the data they need, but the aero modelling in GT is fundamentally flawed which leads to unrealistic top speeds.

Hamilton's role, just like any other celebrity role in previous GT games, is quite superficial. Anything he says on camera is always going to be good things because he got paid for it. If you really think the W08 is realistic wouldn't you think Mercedes F1 team would use GT Sport in all their simulators?

Low speed physics in GT is also one of the worst. Longitudinal tyre grip is pretty much non existent and it's impossible to modulate throttle properly. That's why most online races which have standing starts everyone just uses TCS. Comparing to sims like Assetto, Automobilista and LFS where it's very natural to modulate tyre grip from standing start. Heck even arcade games like Driveclub does a better job at this in some respect.

Aero, I've already said plenty before is messed up in GT. It's not really a case of getting better or worse from previous games because they keep using the same simplifications. Compare this to ACC for example where they model every downforce generating element separately, and also ride height/car rake also influences downforce. It's night and day compared to PD's simple perpendicular force vector.

Pressure sensitive brake pedals already exist. Once again it's just up to PD to implement it. But yet again they disappoint us in GTS by having non linear throttle (and brake to an extent). I mean when I play Assetto with my G25 I'm getting a better experience than GTS with T-GT, you know there's something wrong.
 
729
Brazil
Brazil
And when I said the top speeds of the Challenger R/T and Mustang Mach 1 where ridiculous low for what we're their real specs, I was laughed at even thought I brought in my sources which folks said were wrong.

If you guys think these supercars have unrealistic top speeds, you should see the classics being laughably limited by ****ing rev limiters that shouldn't even be present in the cars to begin with.
 
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K3Tuning

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So hard to just take one result and replicate it under different conditions IRL let alone a video game.

Don't you need to pull over and switch to a top speed key in a different key location to activate the Veyrons top speed mode. So whatever the wing does in regular mode its not representing top speed mode simply going down flat. As mentioned the car also lowers and other performance elements also work to produce top speed. We do not have Top Speed mode for the Veyron in Gran Turismo.

Question, Are speeds 100% identical in both directions on SSRX, this would show if any wind is simulated, IIRC they had wind readings in GT6. The wind speed always relatively small. A 50kmh tail wind sure will help speeds go up as a head wind will slow them down but small 5kmh to 10kmh winds wont have as dramatic an impact.

The ability to test with same wind conditions as real world test is kinda needed & it would be interesting to see if ever we get the Nardo track with its constant banking allowing for higher speeds.

Any top speed result off that track has to have the banking factored out before it can compare to a flat speed. Always faster.

Its for all this and a few more reasons that top speeds in video games are of no concern to me, as long as its not dramatic like a Veyron not busting 300kmh lol or Race cars wildly off from real versions (low drag configurations aside) I don't care.

Before SSRX you rarely find a place for it to show up let alone matter.
 
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1,695
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Tassie_tiger
Well I don't know which version of GT Sport you're playing, but my impressions are all the opposite to yours.

Real life data doesn't mean anything if the game physics can't translate it properly. I'm pretty sure they have all the data they need, but the aero modelling in GT is fundamentally flawed which leads to unrealistic top speeds.

Hamilton's role, just like any other celebrity role in previous GT games, is quite superficial. Anything he says on camera is always going to be good things because he got paid for it. If you really think the W08 is realistic wouldn't you think Mercedes F1 team would use GT Sport in all their simulators?

Low speed physics in GT is also one of the worst. Longitudinal tyre grip is pretty much non existent and it's impossible to modulate throttle properly. That's why most online races which have standing starts everyone just uses TCS. Comparing to sims like Assetto, Automobilista and LFS where it's very natural to modulate tyre grip from standing start. Heck even arcade games like Driveclub does a better job at this in some respect.

Aero, I've already said plenty before is messed up in GT. It's not really a case of getting better or worse from previous games because they keep using the same simplifications. Compare this to ACC for example where they model every downforce generating element separately, and also ride height/car rake also influences downforce. It's night and day compared to PD's simple perpendicular force vector.

Pressure sensitive brake pedals already exist. Once again it's just up to PD to implement it. But yet again they disappoint us in GTS by having non linear throttle (and brake to an extent). I mean when I play Assetto with my G25 I'm getting a better experience than GTS with T-GT, you know there's something wrong.
I'm sorry, but if you think that ride height and car rake don't influence downforce in GT Sport, then your theory of "aero modelling in GT is fundamentally flawed" is ... fundamentally flawed.
 
2,747
United States
Theresa, Wisconsin
I'm sorry, but if you think that ride height and car rake don't influence downforce in GT Sport, then your theory of "aero modelling in GT is fundamentally flawed" is ... fundamentally flawed.

I believe Legend was saying that ride height and rake does in fact alter downforce (negative lift if we are being picky)
 

LeGeNd-1

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Australia
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GTP_LeGeNd-1
So hard to just take one result and replicate it under different conditions IRL let alone a video game.

Don't you need to pull over and switch to a top speed key in a different key location to activate the Veyrons top speed mode. So whatever the wing does in regular mode its not representing top speed mode simply going down flat. As mentioned the car also lowers and other performance elements also work to produce top speed. We do not have Top Speed mode for the Veyron in Gran Turismo.

Question, Are speeds 100% identical in both directions on SSRX, this would show if any wind is simulated, IIRC they had wind readings in GT6. The wind speed always relatively small. A 50kmh tail wind sure will help speeds go up as a head wind will slow them down but small 5kmh to 10kmh winds wont have as dramatic an impact.

The ability to test with same wind conditions as real world test is kinda needed & it would be interesting to see if ever we get the Nardo track with its constant banking allowing for higher speeds.

Any top speed result off that track has to have the banking factored out before it can compare to a flat speed. Always faster.

Its for all this and a few more reasons that top speeds in video games are of no concern to me, as long as its not dramatic like a Veyron not busting 300kmh lol or Race cars wildly off from real versions (low drag configurations aside) I don't care.

Before SSRX you rarely find a place for it to show up let alone matter.

If you read my post on page 1, you will see that PD kinda tried to model the Top Speed mode of the Veyron automatically (the rear spoiler goes down at 370 km/h), but they forgot about lowering the ride height...

It's hard to assess if top speeds are 100% identical on both directions in SSRX because one straight has the bridge and it also depends on how you exit the banking. In any case, for comparison purposes I think wind direction/speed is not a factor in GT. What does have an effect is time of day, specifically temperature. In GT6 the fastest speeds are at 1500-1530 PM because this is when the temperature is hottest (and air density lowest). I haven't tested this specifically in GTS though.

I'm sorry, but if you think that ride height and car rake don't influence downforce in GT Sport, then your theory of "aero modelling in GT is fundamentally flawed" is ... fundamentally flawed.

Erm...I didn't say that in my post. I just said they mattered in ACC.

Ride height and rake does affect aero in GT, just not as much as ACC and in some cases it does stupid things (e.g. the wheelie glitch in previous games, not sure if this has been tried in GTS). All this because aero in GT land is only a simple force vector perpendicular to the body of the car, and I haven't felt anything different to say that this has been fixed in Sport.

For most cars it's an acceptable simplification, but for cars with trick aero (e.g. Huayra's flaps, McLaren F1's fans, and if they ever make it to the game, Huracan Performante's ALA, Zenvo TSR-S' centrifugal wing) GTS is not good enough. So you get inaccurate handling and top speeds with these cars.

In ACC I know they modelled each individual downforce generating element separately (splitter, canards, wing, diffuser). Each with their own downforce vector acting on the exact distance from the car's center of gravity & center of pressure. Ride height and rake is so involved in downforce that their setting is under Aero in the game instead of Suspension. You can see the aero balance % changing real time when you make adjustments, instead of GT's F:R generic numbers that has been with us since GT1 and no one seems to know what they represent...
 
2,747
United States
Theresa, Wisconsin
If you read my post on page 1, you will see that PD kinda tried to model the Top Speed mode of the Veyron automatically (the rear spoiler goes down at 370 km/h), but they forgot about lowering the ride height...

It's hard to assess if top speeds are 100% identical on both directions in SSRX because one straight has the bridge and it also depends on how you exit the banking. In any case, for comparison purposes I think wind direction/speed is not a factor in GT. What does have an effect is time of day, specifically temperature. In GT6 the fastest speeds are at 1500-1530 PM because this is when the temperature is hottest (and air density lowest). I haven't tested this specifically in GTS though.

So the high temp and low air density making it easier to drive through the air trumps the fact that the car will also be making the least horsepower because of the high temps?
 
1,695
Australia
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Tassie_tiger
Erm...I didn't say that in my post. I just said they mattered in ACC.

Ride height and rake does affect aero in GT, just not as much as ACC and in some cases it does stupid things (e.g. the wheelie glitch in previous games, not sure if this has been tried in GTS). All this because aero in GT land is only a simple force vector perpendicular to the body of the car, and I haven't felt anything different to say that this has been fixed in Sport.

For most cars it's an acceptable simplification, but for cars with trick aero (e.g. Huayra's flaps, McLaren F1's fans, and if they ever make it to the game, Huracan Performante's ALA, Zenvo TSR-S' centrifugal wing) GTS is not good enough. So you get inaccurate handling and top speeds with these cars.

In ACC I know they modelled each individual downforce generating element separately (splitter, canards, wing, diffuser). Each with their own downforce vector acting on the exact distance from the car's center of gravity & center of pressure. Ride height and rake is so involved in downforce that their setting is under Aero in the game instead of Suspension. You can see the aero balance % changing real time when you make adjustments, instead of GT's F:R generic numbers that has been with us since GT1 and no one seems to know what they represent...
So, essentially the comment about ACC was a red herring.
Good to know.

BTW, how many other sims (be it console or PC) have ride height included in the Aero settings?

GT Sports aero is either "fundamentally flawed" or it's an "acceptable simplification".
Which one is it?

If you were to increase front downforce, increase rear downforce, increase rear ride height, and the car had a quicker top speed, I would agree that the aero simulation is fundamentally flawed.
Although I'm pretty sure this isn't the case.


*Edit*
Anyway, I've said all I want to say there.
I find the terminology "fundamentally flawed" uneccessary hyperbole.


So, moving on with a general comment ...
I tend to use SSX in a lobby to quickly knock out my daily mileage.
So today I figured I'ld try a few things while I was there.

I always run the Tomahawk X, so that was the car of choice.
Car settings unknown (I assume standard), but I don't think that matters.

I ran the track with 'time of day' settings - 6:10, 11:00, 15:20, 20:00, and 22:30.
I also ran the track backwards.
I took notice of the max. speed down the back straight.

Every run - 591kmh (always just shy of 12,500rpm).
 
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LeGeNd-1

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GTP_LeGeNd-1
So the high temp and low air density making it easier to drive through the air trumps the fact that the car will also be making the least horsepower because of the high temps?

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

So, essentially the comment about ACC was a red herring.
Good to know.

BTW, how many other sims (be it console or PC) have ride height included in the Aero settings?

GT Sports aero is either "fundamentally flawed" or it's an "acceptable simplification".
Which one is it?

If you were to increase front downforce, increase rear downforce, increase rear ride height, and the car had a quicker top speed, I would agree that the aero simulation is fundamentally flawed.
Although I'm pretty sure this isn't the case.


*Edit*
Anyway, I've said all I want to say there.
I find the terminology "fundamentally flawed" uneccessary hyperbole.


So, moving on with a general comment ...
I tend to use SSX in a lobby to quickly knock out my daily mileage.
So today I figured I'ld try a few things while I was there.

I always run the Tomahawk X, so that was the car of choice.
Car settings unknown (I assume standard), but I don't think that matters.

I ran the track with 'time of day' settings - 6:10, 11:00, 15:20, 20:00, and 22:30.
I also ran the track backwards.
I took notice of the max. speed down the back straight.

Every run - 591kmh (always just shy of 12,500rpm).

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*.
 
373
Australia
Australia
wmd351
So the high temp and low air density making it easier to drive through the air trumps the fact that the car will also be making the least horsepower because of the high temps?
That's always been my understanding of it although as far as hp goes I think the lower density of the air is more detrimental to power than the air temp.

That's why land speed record attempts and events are preferably staged at high altitude locations.
 
Oops, saw you mention F1 and torque while skim reading, I see what you mean now. Someone should do a comparison between McLaren F1 GTS vs Real and see how it differs. More car data to correlate with and improvement of simulation should make it all closer. I think PDI are likely to have more clout to get access to more real life data too.

Anyway I think good to bring the W08 up being one of the more complex and recent additions to GT, you can see it is quite realistic in performance. I hope Lewis association with GT is long term and he can help improve GT by giving insights to PDI that only a driver of his calibre would know.

Feels natural enough for me to be fast with it although quite not there yet. I actually find low speed physics in GT Sport very promising for future games. They seem like they are trying to replicate it while most other sim games it doesn't feel like there are really any traction phases, you just mash the throttle and you get close to perfect traction.

Aero simulation is where I think physics of GT is strongest at the moment, can't think of another game better at the moment. I have driven most other sims and that makes me appreciate more how good GT is fundamentally, they really did a huge step going from GT6 to GTS and they are largely being held back by the CPU. They are smart with what they are working on this generation bringing tracks, cars, networking, UI / OS and sound up to a high level ready for next-generation and working on physics underpinnings that could make big step forward with more processing power, going like from 2D to 3D. PDI are usually at the cutting edge of tech and finally with PS5 they will have the platform to make "THE REAL DRIVING SIMULATOR". For long they might have been envious of hardware F1 teams have to develop simulators on but now it's going to be their turn to show their level.

I do hope with better connectivity standards and lower latency that PS5 should have, it opens up potential of a pressure sensitive L2 trigger. Also hopefully there will be more direct drive wheels and pedals with pressure sensitive brake pedal by then, that will make realism much better too.
Aero simulation may be GT Sport’s strong area but I find it really lacking compared to Project Cars 2. In PC2, when you’re in a high speed corner, the steering gets very heavy because of downforce. Sometimes you even need to lower your frontal downforce because it’s too hard to turn!

GT is like driving my Honda Accord, the faster I go, the easier it gets because there’s no downforce at all.

Speaking of which, PD forgot to add frontal downforce to multiple cars like the Enzo and LaFerrari, off the top of my head. As a result, they have terrible understeer in medium to high speed corners.
 
2,747
United States
Theresa, Wisconsin
That's always been my understanding of it although as far as hp goes I think the lower density of the air is more detrimental to power than the air temp.

That's why land speed record attempts and events are preferably staged at high altitude locations.

I dont know if racers have much choice when it comes to the altitude of a particular facility when it comes to land speed type racing, they are pretty much limited to what nature makes available. Bonneville is 4200' above sea level which is awful high for making good horsepower, I am guessing they lose at least 15% of their total power compared to being at sea level. I have no idea where that trade off is between your engine making excellent power because of favorable corrected density altitude numbers and your cars aero being affected by thinner air. I know for a fact that us drag racers will take the low? density altitude numbers everytime that favor making good HP, we want corrected altitude to be near or even below sea level conditions everytime. Even here in the midwest we can easily go from corrected DA of 4500' in mid summer to -200' in fall or 4500' mid summer afternoon to 2000' at midnight on the same day which is worth around 10-15% horsepower. That can easily be 3-4 1/10ths of a second in ET and worth 4 MPH, of course that's standing start so we are not spending much time pushing the car thru the air but it still makes am impressive MPH difference.
 
3,011
PC 2 feels too slow compared to gran turismo sport. I actually prefer gts to pc2 in performance realism. I will use a car at Daytona or monza and it's like every car has 190 mph top speed regardless of class or make in pc2.
 

Greycap

The Flying Finn
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I know for a fact that us drag racers will take the low? density altitude numbers everytime that favor making good HP, we want corrected altitude to be near or even below sea level conditions everytime. Even here in the midwest we can easily go from corrected DA of 4500' in mid summer to -200' in fall or 4500' mid summer afternoon to 2000' at midnight on the same day which is worth around 10-15% horsepower.

Naturally aspirated engines, I presume? Shouldn't be an issue with super/turbocharged engines unless all the available boost is utilized already at sea level, in other words the wastegate being completely closed. Old aircraft piston engines actually made more power at altitude than at sea level as long as they were below the supercharger critical altitude - which is the altitude in which the aforementioned thing happens and the supercharger can't provide enough air to give full boost pressure anymore.
 
2,747
United States
Theresa, Wisconsin
Naturally aspirated engines, I presume? Shouldn't be an issue with super/turbocharged engines unless all the available boost is utilized already at sea level, in other words the wastegate being completely closed. Old aircraft piston engines actually made more power at altitude than at sea level as long as they were below the supercharger critical altitude - which is the altitude in which the aforementioned thing happens and the supercharger can't provide enough air to give full boost pressure anymore.

Yes, naturally aspirated. The old aircraft piston engines were just tuned to make more HP at altitude, if they so desired I'm sure they could have made much more power at sea level.
 

Greycap

The Flying Finn
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Finland
Finland
Those aero engines actually had insane power losses, I remember reading something about 500+ bhp just to drive the huge centrifugal supercharger but as it gave 1000+ bhp in return it was an easy decision to employ it anyway. That's the main reason to the power increasing with altitude as the losses went down in thinner air but the boost remained the same.

Which leads me to the original point of choosing between thinner air and less power vs. thicker air and more power when going for top speed. In a turbocharged car there's no doubt, thinner air is the choice as the power won't be affected unless the turbo is already giving all it has to give - and that's highly unlikely in a high performance car, there's always some headroom. In a naturally aspirated car things may well be different.
 
2,747
United States
Theresa, Wisconsin
Those aero engines actually had insane power losses, I remember reading something about 500+ bhp just to drive the huge centrifugal supercharger but as it gave 1000+ bhp in return it was an easy decision to employ it anyway. That's the main reason to the power increasing with altitude as the losses went down in thinner air but the boost remained the same.

Which leads me to the original point of choosing between thinner air and less power vs. thicker air and more power when going for top speed. In a turbocharged car there's no doubt, thinner air is the choice as the power won't be affected unless the turbo is already giving all it has to give - and that's highly unlikely in a high performance car, there's always some headroom. In a naturally aspirated car things may well be different.

I suppose that all depends on the type of racing. In drag racing if you can make 70# of boost you will run 70-75# of boost at all times. :D
The Top Fuel and blown alcohol superchargers take in the neighborhood of 1500HP just to drive the superchargers.
 
373
Australia
Australia
wmd351
I suppose that all depends on the type of racing. In drag racing if you can make 70# of boost you will run 70-75# of boost at all times. :D
Yep that is true, but having just watched the latest season of Discovery's Street Outlaws No Prep Kings it was interesting to see the turbo cars get raped when they went to a high altitude track (Denver I think it was?) because they didn't have enough time to spool up in staging before the tree went green. The procharger and (obviously) nitro cars had a huge advantage.

No doubt down the quarter mile that wind resistance is'nt going to have stuff all effect on a 60' time but I believe it does become a significant factor in regards to terminal velocity once you get beyond 100 or so mph, hence drag racers liking smaller cars like a Vega or Chevy II, asides from the obvious weight factor.

At the risk of getting somewhat back on topic, I will point out that the Tomahawk X around SSRX does pull an extra 60 kmh top speed when you drop the flaps and go into low drag mode.
 
2,747
United States
Theresa, Wisconsin
Yep that is true, but having just watched the latest season of Discovery's Street Outlaws No Prep Kings it was interesting to see the turbo cars get raped when they went to a high altitude track (Denver I think it was?) because they didn't have enough time to spool up in staging before the tree went green. The procharger and (obviously) nitro cars had a huge advantage.

No doubt down the quarter mile that wind resistance is'nt going to have stuff all effect on a 60' time but I believe it does become a significant factor in regards to terminal velocity once you get beyond 100 or so mph, hence drag racers liking smaller cars like a Vega or Chevy II, asides from the obvious weight factor.

At the risk of getting somewhat back on topic, I will point out that the Tomahawk X around SSRX does pull an extra 60 kmh top speed when you drop the flaps and go into low drag mode.

The flaps are driver adjustable????
 
373
Australia
Australia
wmd351
Only with the wheel, AFAIK. There's no assignable button for the DS4 controller, but wheels still have button assigned for the Low Drag/Nitro (GT6 leftovers)
Yep, G29 and TM wheels have it, but not available on the Fanatec.
It gets the 'Hawk up from 605kmh to 666kmh in time trial at SSRX.
I've had it up to 676 in a slipstream.
 
6,573
United Kingdom
United Kingdom
Well I don't know which version of GT Sport you're playing, but my impressions are all the opposite to yours.

Real life data doesn't mean anything if the game physics can't translate it properly. I'm pretty sure they have all the data they need, but the aero modelling in GT is fundamentally flawed which leads to unrealistic top speeds.

Hamilton's role, just like any other celebrity role in previous GT games, is quite superficial. Anything he says on camera is always going to be good things because he got paid for it. If you really think the W08 is realistic wouldn't you think Mercedes F1 team would use GT Sport in all their simulators?

Low speed physics in GT is also one of the worst. Longitudinal tyre grip is pretty much non existent and it's impossible to modulate throttle properly. That's why most online races which have standing starts everyone just uses TCS. Comparing to sims like Assetto, Automobilista and LFS where it's very natural to modulate tyre grip from standing start. Heck even arcade games like Driveclub does a better job at this in some respect.

Aero, I've already said plenty before is messed up in GT. It's not really a case of getting better or worse from previous games because they keep using the same simplifications. Compare this to ACC for example where they model every downforce generating element separately, and also ride height/car rake also influences downforce. It's night and day compared to PD's simple perpendicular force vector.

Pressure sensitive brake pedals already exist. Once again it's just up to PD to implement it. But yet again they disappoint us in GTS by having non linear throttle (and brake to an extent). I mean when I play Assetto with my G25 I'm getting a better experience than GTS with T-GT, you know there's something wrong.
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.
 

LeGeNd-1

Premium
6,744
Australia
Australia
GTP_LeGeNd-1
Bummer, I have a Fanatec

If it's any consolation, I have a T-GT and I cannot map the DRS function. It seems like it was a glitch in the early versions of the game letting you change it, but if you set the button to anything else it becomes impossible to get it back.

At least, hopefully until the update later this month bringing the Super Formula which promises to bring "manual boost control" (could be KERS, DRS, or both).

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.

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 :)