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[DiRT 4] Constructive feedback on the subject of car-feel and physics: The Ultimate Thread

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KevM said:
That's catching a slide, rather than oversteering.  You could do that exactly the same with a front wheel drive.  It just looks weird the way the front wheels stay dead straight for most of the slide.  An Escort should be the full of the rack!!
"Front wheels should follow drive line, so if you were to powerslide with front wheels almost straight up you'd spin a car. That's what I call forcing a sim to act properly. Your tyres have too much of a grip, so in order to powerslide you have to drive the way a real car would spin."

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hawku0 said:
Here are some real life rally videos with a cornering force telemetry.

Subaru with studded tires on ice:
https://www.youtube.com/watch?v=CRSl82Ts6jM

VW Golf III Kitcar:
https://youtu.be/hTyjKX99nBE

Rallycross on gravel:
https://www.youtube.com/watch?v=yJYNO2LFpUU

BMW M3 E30 rally:
https://youtu.be/7tQ8fbFsOUE

Renault Clio rally:
https://www.youtube.com/watch?v=DTJWcCjplHk

Wales Rally with Mitsubishi Lancer Evo IX:
https://www.youtube.com/watch?v=eIgz7TF9UCQ

None of those cars can sustain over 1G's of total cornering force, yet every single car on Dirt 4 can sustain over 1G's on every surface, every condition and every speed.

Cornering at lateral force of 1G's means that there is a force equal of the car's weight pushing it from the the side.

Let's simplify this so that the most stubborn people on this planet ( @Headlong ) can understand this:
  •  Put a car on a platform which can tilt sideways.
  •  Tilt the platform to a 90 degree angle and add device which somehow adds a force which pushes the car to platform with same force as gravity, which is 1G.
  • There is now 1G's of lateral and vertical force affecting the car.
  • Let's add another half of a car weight to side of the car and now we have the cornering forces of Dirt 4.
  • How does the car still hold on the platform?

Another simplification:
  • Put a car to a flat tarmac surface.
  • Reduce a vertical force of the car to 0 G's
  • Now the lateral force and vertical force are the same. It's the same ratio when when cornering at 1G.
  • How much force would you need to push the car to the side when it doesn't weight anything?
  • How much downforce would you need to add to the car to withstand 0.5G's of lateral force? What speed you have to drive to achieve that downforce?

Of course there are situations where tyres can peak over 1G's, but to sustain over 1G, you would need a massive amount of downforce and a very sticky tarmac.
I don't understand how someone can argue that every car should sustain over 1G's on gravel and ice without any serious downforce.


To keep this thread somewhat constructive, here is my constructive feedback:
  • Maybe we should have a tyre friction coefficient slider on the car setup menu, so we could tune the values to little closer to the realistic values.
  • There should be different sliders for different kind of road surface and off-road surface.
  • Paul Coleman said in one video that we should send them good car setups and those friction coefficient sliders would really help us to help Codies to make the game better and more fun for us sim racers.
This is a great post Thanks for collecting these videos.

On a side note, the Rallycross on gravel clip seems to be a pretty standard car doing some sort or autocross event on gravel? Wouldn't really call that RX though ;)

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Hawku0 said:

Of course there are situations where tyres can peak over 1G's, but to sustain over 1G, you would need a massive amount of downforce and a very sticky tarmac.
I don't understand how someone can argue that every car should sustain over 1G's on gravel and ice without any serious downforce.


They did add a lot of data from one of the major tire companies (forget which it was) as well as added a lot of detail in the aerodynamics of the cars.


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Honestly this whole aero thing ,unless I'm at Pikes Peak in a Quattro at 130 mph I don't need it ............would much rather enjoy a proper tire model and sidewall simulation of it "................or just get us the choice to change tires ,therefore grip

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Narzugon said:
 
Hawku0 said:

Of course there are situations where tyres can peak over 1G's, but to sustain over 1G, you would need a massive amount of downforce and a very sticky tarmac.
I don't understand how someone can argue that every car should sustain over 1G's on gravel and ice without any serious downforce.


They did add a lot of data from one of the major tire companies (forget which it was) as well as added a lot of detail in the aerodynamics of the cars.


For RX they did indeed. And apart from braking distances it works nice.
EDIT: For tyres that is. As for aerodynamics- don't know if those are responsible for rally physics.

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This thread is really weird.  

Between Headstrong, folk quoting what they've said when you agree with them, to wee Grimmi who is shit scared to post anything himself, but follows me around flagging and disagreeing to everything I type - lol

Set the bag of glue down boys....  :D

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KevM said:
This thread is really weird.  

Between Headstrong, folk quoting what they've said when you agree with them, to wee Grimmi who is **** scared to post anything himself, but follows me around flagging and disagreeing to everything I type - lol

Set the bag of glue down boys....  :D
I just quoted myself so you know more people came into the same conclusion. You are not reading this thread post by post, so I wanted to point it out to you. But that's fine, I won't do it again.

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Oh I read it.                                                    

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bogani said:
Is there any vids of R5 cars with a G-meter out there? 
https://youtu.be/10NnPYpssYw
EDIT:This one is the closest, 
I am sure I saw some Hyundai R5 with proper telemetry (including G-meter) before, but cannot find it in my yt history.

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Does anyone else find the R5 cars really gutless?  Maybe it's the sound? 

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A fresh one from this week preevent test, fiesta r5 on dry tarmac :
https://www.youtube.com/watch?v=t9iNeZowu7o
And another one found on youtube, fiesta r5 on gravel :
https://www.youtube.com/watch?v=j8yv02FlfPM

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KevM said:
Does anyone else find the R5 cars really gutless?  Maybe it's the sound? 
arent some of the same sounds used for the wrong cars on r5s ?

i just ask on some of my videos i seen quite a few comment about this.

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dgeesi0 said:
KevM said:
Does anyone else find the R5 cars really gutless?  Maybe it's the sound? 
arent some of the same sounds used for the wrong cars on r5s ?

i just ask on some of my videos i seen quite a few comment about this.
Yep the 208 r5 is using the same sound sample as the fiesta r5 in dirt 4, while IRL the 208 sound a lot more agressive :
https://youtu.be/H_ign3I1z1E?t=8s
https://youtu.be/ngDPMb6N1ww?t=13s

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hawku0 said:
Here are some real life rally videos with a cornering force telemetry.

Subaru with studded tires on ice:
https://www.youtube.com/watch?v=CRSl82Ts6jM

VW Golf III Kitcar:
https://youtu.be/hTyjKX99nBE

Rallycross on gravel:
https://www.youtube.com/watch?v=yJYNO2LFpUU

BMW M3 E30 rally:
https://youtu.be/7tQ8fbFsOUE

Renault Clio rally:
https://www.youtube.com/watch?v=DTJWcCjplHk

Wales Rally with Mitsubishi Lancer Evo IX:
https://www.youtube.com/watch?v=eIgz7TF9UCQ

None of those cars can sustain over 1G's of total cornering force, yet every single car on Dirt 4 can sustain over 1G's on every surface, every condition and every speed.

Cornering at lateral force of 1G's means that there is a force equal of the car's weight pushing it from the the side.

Let's simplify this so that the most stubborn people on this planet ( @Headlong ) can understand this:
  •  Put a car on a platform which can tilt sideways.
  •  Tilt the platform to a 90 degree angle and add device which somehow adds a force which pushes the car to platform with same force as gravity, which is 1G.
  • There is now 1G's of lateral and vertical force affecting the car.
  • Let's add another half of a car weight to side of the car and now we have the cornering forces of Dirt 4.
  • How does the car still hold on the platform?

Another simplification:
  • Put a car to a flat tarmac surface.
  • Reduce a vertical force of the car to 0 G's
  • Now the lateral force and vertical force are the same. It's the same ratio when when cornering at 1G.
  • How much force would you need to push the car to the side when it doesn't weight anything?
  • How much downforce would you need to add to the car to withstand 0.5G's of lateral force? What speed you have to drive to achieve that downforce?

Of course there are situations where tyres can peak over 1G's, but to sustain over 1G, you would need a massive amount of downforce and a very sticky tarmac.
I don't understand how someone can argue that every car should sustain over 1G's on gravel and ice without any serious downforce.


To keep this thread somewhat constructive, here is my constructive feedback:
  • Maybe we should have a tyre friction coefficient slider on the car setup menu, so we could tune the values to little closer to the realistic values.
  • There should be different sliders for different kind of road surface and off-road surface.
  • Paul Coleman said in one video that we should send them good car setups and those friction coefficient sliders would really help us to help Codies to make the game better and more fun for us sim racers.
This is a great post Thanks for collecting these videos.

On a side note, the Rallycross on gravel clip seems to be a pretty standard car doing some sort or autocross event on gravel? Wouldn't really call that RX though ;)


Sorry, but this is nonsense; you have a very incomplete and 2 dimensional understanding of physics and car dynamics.

Below is a video of the Audi Quattro frequently pulling over 1.5 g and peaking at well over 2g lateral on a loose surface at 2:28 in the video.  

https://www.youtube.com/watch?v=5hs-oPzj_9M

I really don't understand why you guys keep doing this. You got a really good rally sim and instead of playing it and having fun you've embarked upon some kind of fault finding quest. 

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Heres a video of me locking the rear diff of the Mk2 and driving (very badly so please forgive me) around Dirtfish but you can see it understeering when I put the power down. Sometimes it does step out but you should be able to throttle control a slide around that donut area and it just doesn't want to. Let me know if I have done a setup wrong though...

https://www.youtube.com/watch?v=SJdJNz9QDOw

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what you want is escort mk2 from dirt rally and dirt 4 side by side.i havent got dirt rally installed or i would do it. cars in dirt 4 feel like something is holding em back at some point.

would be nice to know when we may see some handling tweaks thing is im guessing many are on vacation now after making game so when this tweaking will happen is anyones guess.

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Heres a video of me locking the rear diff of the Mk2 and driving (very badly so please forgive me) around Dirtfish but you can see it understeering when I put the power down. Sometimes it does step out but you should be able to throttle control a slide around that donut area and it just doesn't want to. Let me know if I have done a setup wrong though...

https://www.youtube.com/watch?v=SJdJNz9QDOw
@SirPhilMcKraken have you driven the M3 in Spain?!?  Flip that thing over steers all day long!!  Haha, I wonder if the MK2 has a similar feel in Spain and that it's just gravel physics in general that require needs tweaking

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Heres a video of me locking the rear diff of the Mk2 and driving (very badly so please forgive me) around Dirtfish but you can see it understeering when I put the power down. Sometimes it does step out but you should be able to throttle control a slide around that donut area and it just doesn't want to. Let me know if I have done a setup wrong though...

https://www.youtube.com/watch?v=SJdJNz9QDOw
did you alter suspension at all? like front suspension, dampers and rollbar?

I seem to sorta be able to get cars to behave better by altering all the above, I don't actually know how to doughnut though so probably not one to base testing on. xD

EDIT: well actually a doughnut isn't so hard, can't manage to control a slide around that circular skid area though. (thought I had the wrong definitions! )

EDIT2: erm... in the tuning area is that front toe in description correct?

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I managed to get the Fiesta R5 to behave quite nice in Sweden last night. I still feel the front end of the car can change direction too quick on occasion resulting in some wobbly steering inputs.


The default setups does not do the game any favours though.

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Heres a video of me locking the rear diff of the Mk2 and driving (very badly so please forgive me) around Dirtfish but you can see it understeering when I put the power down. Sometimes it does step out but you should be able to throttle control a slide around that donut area and it just doesn't want to. Let me know if I have done a setup wrong though...

https://www.youtube.com/watch?v=SJdJNz9QDOw
@SirPhilMcKraken have you driven the M3 in Spain?!?  Flip that thing over steers all day long!!  Haha, I wonder if the MK2 has a similar feel in Spain and that it's just gravel physics in general that require needs tweaking
I haven't yet no but I'll give it a go! I have driven the Escort and it does understeer there as well but if you hit the edge of the track ever so slightly then the back just snaps round.

nbates66 said:
Heres a video of me locking the rear diff of the Mk2 and driving (very badly so please forgive me) around Dirtfish but you can see it understeering when I put the power down. Sometimes it does step out but you should be able to throttle control a slide around that donut area and it just doesn't want to. Let me know if I have done a setup wrong though...

https://www.youtube.com/watch?v=SJdJNz9QDOw
did you alter suspension at all? like front suspension, dampers and rollbar?

I seem to sorta be able to get cars to behave better by altering all the above, I don't actually know how to doughnut though so probably not one to base testing on. xD

EDIT: well actually a doughnut isn't so hard, can't manage to control a slide around that circular skid area though. (thought I had the wrong definitions! )

EDIT2: erm... in the tuning area is that front toe in description correct?
I didn't adjust the suspension tab, I did adjust the toe angles though which I tried to show briefly which did seem to have a slightly positive effect. I have a feeling though that the toe descriptions or slider is currently wrong so I don't know which way to move them xD

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Hi all! New to the forums ;)

I tried tuning the Mk2 yesterday too and I think I managed to get some nice powersliding out of it, so I thought I post it here.

In addition to increasing the driving lock (28%), I also gave it a decent amount of preload. Around 80Nm, because it seemed to help with getting the rear loose and having more traction in the corner. More resulted in me constantly spinning :D. For the braking lock I choose 8%, because I felt that way I had more control over the car while braking and initiating some pendulum turns. Braking force was at 2732 Nm, bias at 56%. To further help with the steering to overcome understeer, I added some front toe-in (0.3°). For the anti-roll bars, I set the front to around 5.45 N/mm, and the rear to 9N/mm. Additionally I made the spring rates a tiny bit softer and set all the damping settings to -2.

The roll-bars seemed to change a lot for me, but they certainly have a very narrow sweetspot. A rear bar, thats too soft prevents the rear from going out, a rear bar, thats too firm results in spinnig around. For the front a softer setting helps against understeer, because of the increased traction. But when its too soft, it again just glues the front to the ground and spins the car (thats how I feel about it). Here, the gravel at DirtFish seems to be more forgiving, but for wales I had the front bar to be firmer (around 10N/mm (rear was 10-12N/mm)).

I didn't play around with the wheel-camber that much, but my guess is, that a setting of -1.5° might be not bad.

For the braking bias, I personally wouldn't go under 54%. If its too unstable, maybe up to 70% like the default setting.


Hope this helps, and feel free to correct if I'm wrong about something, because I'm not an expert ;).

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fab1701 said:
Hi all! New to the forums ;)

I tried tuning the Mk2 yesterday too and I think I managed to get some nice powersliding out of it, so I thought I post it here.

In addition to increasing the driving lock (28%), I also gave it a decent amount of preload. Around 80Nm, because it seemed to help with getting the rear loose and having more traction in the corner. More resulted in me constantly spinning :D. For the braking lock I choose 8%, because I felt that way I had more control over the car while braking and initiating some pendulum turns. Braking force was at 2732 Nm, bias at 56%. To further help with the steering to overcome understeer, I added some front toe-in (0.3°). For the anti-roll bars, I set the front to around 5.45 N/mm, and the rear to 9N/mm. Additionally I made the spring rates a tiny bit softer and set all the damping settings to -2.

The roll-bars seemed to change a lot for me, but they certainly have a very narrow sweetspot. A rear bar, thats too soft prevents the rear from going out, a rear bar, thats too firm results in spinnig around. For the front a softer setting helps against understeer, because of the increased traction. But when its too soft, it again just glues the front to the ground and spins the car (thats how I feel about it). Here, the gravel at DirtFish seems to be more forgiving, but for wales I had the front bar to be firmer (around 10N/mm (rear was 10-12N/mm)).

I didn't play around with the wheel-camber that much, but my guess is, that a setting of -1.5° might be not bad.

For the braking bias, I personally wouldn't go under 54%. If its too unstable, maybe up to 70% like the default setting.


Hope this helps, and feel free to correct if I'm wrong about something, because I'm not an expert ;).
Thanks for the suggestions, I will give these a go :)

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