[solved] The world physics and tyre physics need "tuning"

[Scaff]

The reason the inside wheel is lifting is a direct result of the high level of grip being generated by the outside tyre. All those pics prove @mattikake 's point the Clio Cup doesn't have the same level of rear end grip in the game.

I have to admit that I didn't yet buy PCars 2 so I can't personally comment directly about the car drives in that game. However, I remembered how loose the rear and of the Clio Cup was in PCars1 so I just fried it up again and ran a few laps around Brands Hatch to remind me exactly what I was dealing with and I came to the same conclusion. Driving that Clio should not be about managing a loose rear end, particularly at relatively low speeds. If anything should be managed it should be understeer and I believe being over aggressive on the throttle during cornering is the last thing that should be done.

I do own and have tracked a Renaultsport Clio on semi-slick tyres so I have a modicum of experience of how these cars behave but the racer takes the grip levels to a higher degree as can be seen here:

The reason the rear lifts and it tripods is down to the far softer front set-up and firmer rear, the grip is being generated at the front of the car and the very aggressive diff allows you to drag it around.

As this Clio Cup driver explains.



Start at 1.45

It's perfectly possible to get heat in the rears, but its never going to be at the same level as the fronts.

You need to be aggressive with the car and throttle, brake late and hard, get the weight over the front. Apex a little later than normal, turn in hard (this is when the rear is likely to lift) and bury the throttle.

The diff will get you through the corner and drag the rear along in a stable manner, this also help get heat into the rear.

Video demonstrating it in PC2 is on its way.

 

[turnupdaheat]

Respectfully, based on your response above, you have a great deal to learn about front wheel drive race cars and how they handle in the real world.

Which part do you disagree with?

The Clio Cup in PC1 is not the same as in PC2. In PC1 it's much harder to handle than in PC2. As already pointed out by people that drove it, like a lot, and are on/near the top of the leaderboards. See also the videos of actual Clio Cup races above, snap oversteer galore. This car only kills when not driving it properly (the onboard IRL race video a few posts up demonstrates this).

Doesn't that race vid show exactly what you're saying shouldn't happen?

If the PC2 Clio handles differently to the PC1 version I'll have to hold fire on commenting on it directly.

If presume right that you are talking about the first lap spins and I would put most of the incidents down to cars making contact to the rear end of the car in front but certainly the car that lost it on the way down to Graham Hill Bend did lose the rear end under braking on cold tyres. Other than that I believe the video demonstrated the high levels of grip that car is capable of and was missing in PC1.

Edit:

The reason the rear lifts and it tripods is down to the far softer front set-up and firmer rear, the grip is being generated at the front of the car and the very aggressive diff allows you to drag it around.

Yes agreed, but that is combined with the grip provided by the rear "leg" of that tripod and in the real car on warm tyres it's rare the see the type of tank slapper that's visible in @mattikake 's video.

 

[Scaff]

Clio Cup Car at Brands Hatch GP.

Second lap from the pits, driven as I explained in the post above.

 

[rono_thomas]

A quick 10 minute test for you, note I’m on a cold track at night current date, note also the higher tyre pressures the car is crazy twitchy as you no doubt will see.

But knowing what its telling me is important, second to last lap is the quickest with me up on my laptime but being too greedy on the last lap.

Im on stock setup except for changing two things in the rear suspension I know will create heat. No doctored video, warts and all are included, with enough running sub 1:30 totally possible 👍

(I do flash the telemetry up occasionally)

 

[mattikake]

^ nice but it looks like you're still struggling like hell to me. Or rather, it's all over the place! You can watch all real the footage you like or try for real, the cars just aren't this twitchy. Maybe it's the new tyre model trying to give you a chance to correct issues you can not just feel but have a chance to see as well?

tbf I had given up and wasn't really trying by the time felt the need to hit record. I'd been going 30 mins beforehand trying to get some normal behaviour. I haven't been trying since day 2 on PC2 really. But what I've discovered is the steering input seems wrong. I found in the second race I could get round the corners just as well with much less steering input and it was far less twitchy as a result. Putting what felt like the right amount in - that was too much - seemed to take it over the edge on the numbers and it would go down of path of miscalculation. If you whacked the steering over too much in that is way beyond the abilities of the available traction, it should want to understeer, not continue to turn regardless resulting in massive oversteer.

But as said, it seems the steering sensitivity was all wrong with the first race v's the second race. In the second race all I did was realise I didn't have to put as much input in as I did first time and it would still go round the corners fine. It just felt and behaved wrong.

 

[Gr8_Lakes]

I did one race with the Clio the other night. I like how it handles. It required an extremely different driving style to keep it from swapping ends. One thing I did find, the steering ratio was too tight for me in the car's settings. I use a T300 wheel on 1080 degrees. For the number of corrections I was having to make, the stock setting was too twitchy for me. After loosening it up a couple places (can't recall the exact ratio) I was able to keep her pointing forward - until I had to spike the brakes mid corner to avoid hitting the two guys battling in front of me. Leave yourself some room for this reason.

 

[Johnnypenso]

^ nice but it looks like you're still struggling like hell to me. Or rather, it's all over the place! You can watch all real the footage you like or try for real, the cars just aren't this twitchy. Maybe it's the new tyre model trying to give you a chance to correct issues you can not just feel but have a chance to see as well?

tbf I had given up and wasn't really trying by the time felt the need to hit record. I'd been going 30 mins beforehand trying to get some normal behaviour. I haven't been trying since day 2 on PC2 really. But what I've discovered is the steering input seems wrong. I found in the second race I could get round the corners just as well with much less steering input and it was far less twitchy as a result. Putting what felt like the right amount in - that was too much - seemed to take it over the edge on the numbers and it would go down of path of miscalculation. If you whacked the steering over too much in that is way beyond the abilities of the available traction, it should want to understeer, not continue to turn regardless resulting in massive oversteer.

But as said, it seems the steering sensitivity was all wrong with the first race v's the second race. In the second race all I did was realise I didn't have to put as much input in as I did first time and it would still go round the corners fine. It just felt and behaved wrong.

FWD race cars are tuned for lift off oversteer. You control it with throttle and steering input for the most part. Throttle induces understeer at the point where the car wants to swap ends. So in a RWD car you don't punch the throttle mid corner as the back end gets loose but in an FF you do. It's completely counterintuitive but it works. It requires a completely different driving style to all other drivetrains. It requires a great deal of practice to get it right, to the point where you can lap endlessly without worrying about the back end coming around. Until you reach that point, it can and will feel "wrong", when, in fact, it's right. Once you get the hang of it, you can make the car dance.

 

[GordonS]

Clio Cup Car at Brands Hatch GP.

Second lap from the pits, driven as I explained in the post above.

The driving in the video is not natural at all. It is like you are holding back and being extreme careful with too much braking approaching fast corners. That tells me there is something wrong in tyre physics/ physics.

 

[blowfishrulez]

The driving in the video is not natural at all. It is like you are holding back and being extreme careful with too much braking approaching fast corners. That tells me there is something wrong in tyre physics/ physics.

Have you even read and understood what was explained before? Scaffs Video gives you a demonstration of how it’s done. The Clio also is the car that Nicholas Hamilton is driving professionally and he loves how authentic it drives in PCars as well as PCars 2. Since the op I only heard “it looks wrong, it feels weird, it’s broken” with no reasonable argument whatsoever.

 

[GordonS]

Have you even read and understood what was explained before? Scaffs Video gives you a demonstration of how it’s done. The Clio also is the car that Nicholas Hamilton is driving professionally and he loves how authentic it drives in PCars as well as PCars 2. Since the op I only heard “it looks wrong, it feels weird, it’s broken” with no reasonable argument whatsoever.

Yes I have.
Fact is the driving pace should be much faster to bring up possible bugs in the game software.
This is a real life lap at the combined Nürburgring lap with fantastic pace:

This is what I want to see when testing the game - not overly careful braking.

 

[NLxAROSA]

If the PC2 Clio handles differently to the PC1 version I'll have to hold fire on commenting on it directly.

I can only recommend you get PC2 then, it's an absolute blast. 👍

A quick 10 minute test for you, note I’m on a cold track at night current date, note also the higher tyre pressures the car is crazy twitchy as you no doubt will see.

Thanks for the vid, gives me some nice inspiration to take off a few tenths/seconds of my own time. 👍

The driving in the video is not natural at all. It is like you are holding back and being extreme careful with too much braking approaching fast corners. That tells me there is something wrong in tyre physics/ physics.

Or it's just @Scaff being careful. But I guess you see what you want to see...

This is what I want to see when testing the game - not overly careful braking.

There's no overly careful braking in @rono_thomas 's vid. And it's a pretty fast lap.

 

[Scaff]

The driving in the video is not natural at all. It is like you are holding back and being extreme careful with too much braking approaching fast corners. That tells me there is something wrong in tyre physics/ physics.

Its the second lap from the pits on a track that is not hot and you expect no degree of caution at all?

That aside you seem to have missed the video above with a Clio Cup driver explaining that the diff requires this to extract the maximum out of the car (or cars of this set-up), the basic point are perfectly valid and how the cars are driven in the real world.

As for the physics being wrong as a result?

Which part of real world physics makes this wrong?

 

[GordonS]

A quick 10 minute test for you, note I’m on a cold track at night current date, note also the higher tyre pressures the car is crazy twitchy as you no doubt will see.

But knowing what its telling me is important, second to last lap is the quickest with me up on my laptime but being too greedy on the last lap.

Im on stock setup except for changing two things in the rear suspension I know will create heat. No doctored video, warts and all are included, with enough running sub 1:30 totally possible 👍

(I do flash the telemetry up occasionally)

This Rono_Thomas's video is a good informative example. It shows the rear end is all over the place saved only by good driving/reactions.

Again in real life none of that happens:

If I see correctly the track is a bit wet too.
So all this tells, there is something suspicious under the Pcars2 Clio physics.

 

[blowfishrulez]

These cars have a very soft front ARB and a rigid, next to unsprung live axle in the rear. There is just no way to shift inertia to the rear to get it into understeer. I reckon the weight distribution during braking as well as throttle lift off is more like 90% on the front. So yeah, to keep it planted, brake hard in a straight line and stomp the throttle on turn in to make the rear follow the front. The video above does not show anything contrary to that.

 

[jake2013guy]

However, when the BTCC and Clio guys were on slicks they were not struggling to get heat in the tyres and suffering with massive oversteer on cold rears like I and everyone else in the online session.

Yes, they were. Matt Simpson (on slicks) struggled at the start of race 3 when the track hadn't dried yet. Or Jack Goff in race 1.

 

[Scaff]

Again in real life none of that happens:

If I see correctly the track is a bit wet too.

Did you not watch the opening lap?

So all this tells, there is something suspicious under the Pcars2 Clio physics.

As I've already asked "Which part of real world physics makes this wrong"?

After all its not as if Touring cars have the rear step out ever and the drivers use a wide open throttle to save it, is it?

 

[OdeFinn]

Wtf..

Game videos people are fighting against oversteer and real life against understeer.
Like real-life driver says at he has to be at max on power or you end up UNDERSTEER..

Something isn't right.

Ps.every real-life video slide above was with brake.

 

[Scaff]

Wtf..

Game videos people are fighting against oversteer and real life against understeer.
Like real-life driver says at he has to be at max on power or you end up UNDERSTEER..

Something isn't right.

No he didn't, he said the old car (previous generation Clio Cup) would understeer on full throttle and that the new car (which is the same cars in PC1 and PC2) allow you to use full throttle when cornering due to the diff.

Ps.every real-life video slide above was with brake.

And? No one is saying otherwise and PC2 isn't demonstrating power-on oversteer with the Clio or TC's, as such why that needs to be pointed out is beyond me.

 

[rono_thomas]

Wtf..

Game videos people are fighting against oversteer and real life against understeer.
Like real-life driver says at he has to be at max on power or you end up UNDERSTEER..

Something isn't right.

It drives exactly the same as the real life videos shown. Theres really nothing wrong.

 

[OdeFinn]

No he didn't, he said the old car (previous generation Clio Cup) would understeer on full throttle and that the new car (which is the same cars in PC1 and PC2) allow you to use full throttle when cornering due to the diff.

I have now watched/listened video several times and driver states just different way of understeer.
Old car was understeering on exit, and current on entry/mid.

 

[Scaff]

I have now watched/listened video several times and driver states just different way of understeer.
Old car was understeering on exit, and current on entry/mid.

So have I and I disagree.

However please explain why you think (referencing real world physics) that PC2's behavior is so wrong.

 

[Imari]

 

[turnupdaheat]

PC2 isn't demonstrating power-on oversteer with the Clio or TC's

It does seem you have to deal with power-on oversteer a couple of times during your video lap. Exiting Surtees at the 45 second mark and at Clearways at the 1:45 mark and at those points the rears should be obediently following their leaders.

Also, with respect, I would suggest you are generally cornering in too low a gear. The 1.6 turbo engine is a relative torque monster, compared to the previous and revvy 2.0 NA motor, and will pull strongly out of the corners from lower in the rev range. You are constantly bouncing off the limiter and will lose a lot of potential laptime doing so.

 

[Scaff]

It does seem you have to deal with power-on oversteer a couple of times during your video lap. Exiting Surtees at the 45 second mark and at Clearways at the 1:45 mark and at those points the rears should be obediently following their leaders.

Yaw and the grip provided by the front end allows the rear to step out. Its not really power-on in the sense that it would be in a RWD car, as in the driven wheels torque overwhelming the available grip of the tyre, but rather the lateral forces on the rear tyres overwhelming the available grip of the tyres

Also, with respect, I would suggest you are generally cornering in too low a gear. The 1.6 turbo engine is a relative torque monster, compared to the previous and revvy 2.0 NA motor, and will pull strongly out of the corners from lower in the rev range. You are constantly bouncing off the limiter and will lose a lot of potential laptime doing so.

In some of the corners I would agree, it was the second lap in the car and wanted to show it was possible to drive it at that stage without any major lift-off oversteer. Subsequent laps saw more heat in the rears and higher gears used for a number of corners.

 

[NLxAROSA]

Yaw and the grip provided by the front end allows the rear to step out. Its not really power-on in the sense that it would be in a RWD car, as in the driven wheels torque overwhelming the available grip of the tyre, but rather the lateral forces on the rear tyres overwhelming the available grip of the tyres

Wasn't it just lift-off oversteer on both occasions? I see you lift the throttle a bit on both occasions, inducing lift-off oversteer to put the car in the right direction before flooring it? After you put down the throttle it's just going where it's pointing.

 

[dQuim]

Clio Cup Car at Brands Hatch GP.

Second lap from the pits, driven as I explained in the post above.

Thanks for the video. Been struggling slightly with lift-off oversteer on this car - specifically at the McLaren/Clearways turn at Brands Hatch Indy (first career Clio Cup event).

 

[Scaff]

Wasn't it just lift-off oversteer on both occasions? I see you lift the throttle a bit on both occasions, inducing lift-off oversteer to put the car in the right direction before flooring it? After you put down the throttle it's just going where it's pointing.

Its most likely a combination of the two.

 

[GordonS]

As I've already asked "Which part of real world physics makes this wrong"?

The virtual car doesn't seem to follow real world - rear too nervous. Is it not obvious?

 

[Imari]

The virtual car doesn't seem to follow real world - rear too nervous. Is it not obvious?

No. Especially when you say this after several videos of real world Clios spinning out and in game ones being driven relatively smoothly. And vice versa. Judging by comparing what is shown in the videos, it seems about as close as one is going to get out of a game.

On the other hand, those complaining about it are showing a remarkable misunderstanding of the car, what it can and should do, and driving dynamics in general. It seems difficult to accept someone's subjective assertion that the physics are "wrong" when they don't actually understand what "right" should look like.

 

[Scaff]

The virtual car doesn't seem to follow real world - rear too nervous. Is it not obvious?

Nope, not at all.

FWD Touring cars are known for being very tail happy, its effectively engineered into the regulations. The Clio add a much shorter wheel base (in comparison to BTCC/WTCC/TCC spec cars) to that, which is going to make that even more pronounced.