AC GT3 @ Spa - Sunday 29th August 2021

[Kek700]

@demetri

Pheew thought it was me Demetri, exactly the same when I drive it, perfect balance, a joy to drive, then out of nowhere a slow spin. and overheated tyres.
Did some experiment with this, I found at the limit the rears overloads in an instant, by itself no problem, but the tyre will immediately go into the red.
This will not allow you to correct any slide, it then turns into a tyre with a full grip on the back and a tyre in the red. Not a hope in hell of catching it.
Even if you do, you have a quarter of a lap before it is drivable again.
Certainly, something is very wrong with AC tyre data.
Has anyone else an input on this.

PS 1
I should add, I also noticed when experimenting that it is me, I just may not quite get a line correct into a corner, very marginal, I may make a very small correction, hardly noticeable to the human eye, maybe a quicker turn of the wheel into a corner.
Something, if you are not looking for it, you would easily miss.
This is all it needs to set the chain of events off.

 

[Goblin616]

@demetri

Pheew thought it was me Demetri, exactly the same when I drive it, perfect balance, a joy to drive, then out of nowhere a slow spin. and overheated tyres.
Did some experiment with this, I found at the limit the rears overloads in an instant, by itself no problem, but the tyre will immediately go into the red.
This will not allow you to correct any slide, it then turns into a tyre with a full grip on the back and a tyre in the red. Not a hope in hell of catching it.
Even if you do, you have a quarter of a lap before it is drivable again.
Certainly, something is very wrong with AC tyre data.
Has anyone else an input on this.

Here's my input: AC tyres are awful

 

[demetri]

@demetri

Pheew thought it was me Demetri, exactly the same when I drive it, perfect balance, a joy to drive, then out of nowhere a slow spin. and overheated tyres.
Did some experiment with this, I found at the limit the rears overloads in an instant, by itself no problem, but the tyre will immediately go into the red.
This will not allow you to correct any slide, it then turns into a tyre with a full grip on the back and a tyre in the red. Not a hope in hell of catching it.
Even if you do, you have a quarter of a lap before it is drivable again.
Certainly, something is very wrong with AC tyre data.
Has anyone else an input on this.

The thing is I don't think they got red for me and they were more or less fine after that, no quarter of lap needed

 

[Kek700]

Not the answer I was expecting.

 

[demetri]

See the video. With overheated tires, I wouldn't have been able to take Pouhon almost normally after that

 

[Interslice]

See the video. With overheated tires, I wouldn't have been able to take Pouhon almost normally after that

Do you normally enter the corner like that with the dab of the brake at the end of the trail? Looks like there is a slight bump on the inside there.

 

[demetri]

Do you normally enter the corner like that with the dab of the brake at the end of the trail? Looks like there is a slight bump on the inside there.

Honestly, I have no idea, I don't look at the bars when I'm driving, I just try to feel what the car is telling me. Probably not the way I would usually brake there, I think I realized I was going in a bit faster than I should've and tried to slow it down more and maybe it even caused the rear to step out, but the point is that kind of spin is typically very easy to correct, at least in the Audi

 

[beginer]

See the video. With overheated tires, I wouldn't have been able to take Pouhon almost normally after that

My lambo experience:

This is the same thing that happened when i was in the lambo. I figured it was me not balancing the weight of the car properly. I felt like there was severe lift off oversteer which, if memory serves, was corrected by increasing differential coast. (it looks like your slide happened after lift off oversteer would have happened)

The rest was about balancing the car through the corner by blending in throttle as i was lifting off the break (left foot breaking). The car didnt seem to like crusing through the corner without any throttle.

I was wondering if this was a mid engine car issue (the seemingly ultra sensitivity to weight transfer) what do yall think?

 

[demetri]

My lambo experience:

This is the same thing that happened when i was in the lambo. I figured it was me not balancing the weight of the car properly. I felt like there was severe lift off oversteer which, if memory serves, was corrected by increasing differential coast. (it looks like your slide happened after lift off oversteer would have happened)

The rest was about balancing the car through the corner by blending in throttle as i was lifting off the break (left foot breaking). The car didnt seem to like crusing through the corner without any throttle.

I was wondering if this was a mid engine car issue (the seemingly ultra sensitivity to weight transfer) what do yall think?

On the previous lap:

In the R8 on soft tires after 30 minutes of a race (and 25 diff coast!):

And I repeat, it didn't feel a single bit strange until I countersteered and applied throttle but absolutely nothing happened in regards to stopping the developing spin

 

[Interslice]

My lambo experience:

This is the same thing that happened when i was in the lambo. I figured it was me not balancing the weight of the car properly. I felt like there was severe lift off oversteer which, if memory serves, was corrected by increasing differential coast. (it looks like your slide happened after lift off oversteer would have happened)

The rest was about balancing the car through the corner by blending in throttle as i was lifting off the break (left foot breaking). The car didnt seem to like crusing through the corner without any throttle.

I was wondering if this was a mid engine car issue (the seemingly ultra sensitivity to weight transfer) what do yall think?

Yep, generally the mid engine cars are more sensitive on the corner entry, while the front engine cars are twitchy on the exits.
Sounds like higher diff coast would help you alright.

 

[Kek700]

I don't understand the not in red tyres bit, but I know that the car is very knife edgy on that type of corner entry.
There is a bigger delay before you go on the throttle in the shot of your spin + your spin picture the car is understeering a lot more so I assume that is delaying your throttle + your corner entry speed is much higher probably causing the car not to turn.
There was probably a point where one tyre was asked to do more than it was capable of, that would almost certainly be rear left side.
The next corner uses the other rear tyre, so it is very possible it went into the red, not too badly, and cooled sufficiently before the next left-hand corner which is a long way down the track.
All very knife-edge and confusing to why such a dramatic finish to a not very big reason.
Typical Lamborghini.

 

[demetri]

Yeah, it was my mistake of not scrubbing enough speed and entering too fast, but the transition from understeer to oversteer went way faster than what I'm used to driving the Audi. Could've been one of the Lambo's quirks. Or it might be curable by a setup adjustment. I haven't driven this car long enough to make a qualified judgement

 

[RasmusP]

Not the answer I was expecting.

View attachment 499762

See the video. With overheated tires, I wouldn't have been able to take Pouhon almost normally after that

I enjoyed reading all your posts about the lambo issue!
3 years ago (I think) I was practicing the Nordschleife with the Lambo with the help of Matteo Caruso. We tried to create a good setup and definitively build a very nice one!

Story:
He never spun. Not once. And was 15 seconds quicker than me... He's one of the best "weight shift managers" I've ever come across.
Meanwhile I was spinning or understeering out of the corner every second lap.
I was braking earlier, going in slower, coming out slower and being more careful and still spun on the exact same setup.

Bottom of it:
The Lambo definitely has some weird "issue" with weight shifts. I always spun after coming off the brakes like Dmitry.
Alternatively I understeered because the front became too light...
Only when I got the throttle lifting and trail braking correct, I magically didn't spun nor understeered and could do the corner 20 kph faster.

I practiced Flugplatz for 2 weeks (about 30 minutes every second day) until I got it consistently correct.
Sadly I don't have the videos if my fails anymore but in the end I could do it without braking, just a slllooooowwwww lift of the throttle and a still slow, but a bit quicker push on it at the apex.

Sometimes the rear tyres go hot, sometimes they don't. However we all agree that the Lambo loses it slowly but without any hope of catching it.

I would love to believe it's like that in reality but then you take the Lambo in ACC for a "spin" (pun intended...) and it doesn't do the same.

I get a similar behavior in the McLaren in AC btw. It's different though.. With the McLaren im on knifes edge and at one moment in time it will just insta-snap and wipe out.
It always feels like I just went beyond limits but honestly I think the root of that is similar to the Lambo-Issue...

 

[Kek700]

Thank you for your comments Rasmus, nice that it is just not me, I was quite pleased when Dmitry posted the above, he is on another level to me, so when he got clobbered by the Lambo I was relieved. Sorry, Dimtry.

I drove Monza with one eye on the telemetry and one on the road, not easy, started to see a trend on one particular corner. ( must find out how to run a video whilst I am driving.)
If I changed anything to do with that corner, later turn in, too much speed, too much or a sudden wheel input, ( we are talking marginal here, certainly not obvious ) anything that was different the left rear, suddenly went into overload conditions.
Now it did not always mean a red tyre and slow spin, but it soon became obvious that it was a series of combinations that made the difference between an all-wheel drift and a slow spin with a red tyre.
It is the speed that the tyres turn red, is that real. ????
I discovered that I can have a nice setup for me; Lamborghini is for 15 laps, 20 laps, but once those combinations are meet, invoked, away it goes.
That is for me what makes it so difficult, you start to relax, think you have it sorted, then wham it's gone.
I am now trying to learn the McLaren, and now drive it quite thoughtfully, unlike the Nissan where I can easily go off and have a daydream whilst driving it.

 

[RasmusP]

Thank you for your comments Rasmus, nice that it is just not me, I was quite pleased when Dmitry posted the above, he is on another level to me, so when he got clobbered by the Lambo I was relieved. Sorry, Dimtry.

I drove Monza with one eye on the telemetry and one on the road, not easy, started to see a trend on one particular corner. ( must find out how to run a video whilst I am driving.)
If I changed anything to do with that corner, later turn in, too much speed, too much or a sudden wheel input, ( we are talking marginal here, certainly not obvious ) anything that was different the left rear, suddenly went into overload conditions.
Now it did not always mean a red tyre and slow spin, but it soon became obvious that it was a series of combinations that made the difference between an all-wheel drift and a slow spin with a red tyre.
It is the speed that the tyres turn red, is that real. ????
I discovered that I can have a nice setup for me; Lamborghini is for 15 laps, 20 laps, but once those combinations are meet, invoked, away it goes.
That is for me what makes it so difficult, you start to relax, think you have it sorted, then wham it's gone.
I am now trying to learn the McLaren, and now drive it quite thoughtfully, unlike the Nissan where I can easily go off and have a daydream whilst driving it.

It's an often discussed topic in physics discussions about ac that the tyres "work quite well" and "are fun", but sometimes you can see the flaws.
One big weak spot of AC is the Tyre temperature simulation from what knowledgeable guys said.

Toe and psi barely influence the temperatures, overheating is a bit "weird" etc.
Mostly it's not an issue but sometimes you run into a critical situation and wonder if you're stupid or if AC might be a bit unrealistic regarding that one moment.

To see how completely different things can be, compare acc, rf2 and ac regarding Tyre temperatures.
And apparently some really well done AC mod cars are a whole different experience.
I just didn't test one of these cars yet...

There's one paymod lmp2 car iirc that mclarenf1papa worked at and he's involved in professional lmp2 simulations of a real pro team.

I'll dig that one out when I'm home from my holidays!

I feel we know as much about this topic as much as I could see at the summit of the Zugspitze yesterday

 

[Kek700]

At first, I thought you were talking to one of our resident aliens.

 

[demetri]

It's an often discussed topic in physics discussions about ac that the tyres "work quite well" and "are fun", but sometimes you can see the flaws.
One big weak spot of AC is the Tyre temperature simulation from what knowledgeable guys said.

Toe and psi barely influence the temperatures, overheating is a bit "weird" etc.
Mostly it's not an issue but sometimes you run into a critical situation and wonder if you're stupid or if AC might be a bit unrealistic regarding that one moment.

It wasn't always like that. I believe this behavior came with V10 tire model back in mid-2016. Earlier AC versions would not suffer as much from tires getting overheated so soon. I remember being able to run Super Soft compound on the 458 GT2 at Spa at +26 air/+37 track temps. For a few laps in a row, I think it was four laps, definitely more than two, until the tires simply wore out and lost grip. Pushing it as max as I could all the time to get those coveted 2:15 times.
Good luck doing all that nowadays, the tires will turn into butter by the end of sector 2 if not even earlier.

 

[Goblin616]

Remember that time I fell through the map at practice for Le Mans?

Is it fair to keep it as the speed record in ACCM?

Spoiler: click

 

[Goblin616]

Does anybody want to practice for zandvoort? i'm driving tt there now.

 

[Kek700]

It’s 1:30am here Frank, most are tucked up in bed, it’s only the ones who cannot sleep that are about, ie me.