AC RaceDepartment European GT Championship 2021

[Interslice]

Didn't we have that yesterday?

Just you Tim

 

[Chris Down]

On RSR the porsche is generally quicker on every normal track by .2 - .5. It's tires go off faster than the maser though... unless you flatspot the maser tyres. Hard to know the balance with them.

Race trim is very different, just look at quali yesterday: I was faster in the 650s in quali, but I knew that Dmitri will be faster in the race even then just because Dmitri was forced to use the mediums in quali due to R8 tyre heating.

In my experience it was the same with the Maserati and Porsche, the Porsche is better than the Maserati in quali trim, but the Maserati tends to be better in race trim, so RSR is a little misleading.

Ye it's pretty similar to gt-r vs 488 or whtaever. Is that with or without the assists on the maser? Over a lap or a 1 hour distance?

The Porsche is generally better over 1 lap and the Maserati is equal or better over race distance. Depends a bit on the track though.

Assists don't matter much for most people at the top I guess, I don't remember whether it was with or without. Hard to say for further down the field, but it shouldn't make any appreciable difference for frontrunners other than being marginally more consistent with ABS.

 

[Interslice]

Race trim is very different, just look at quali yesterday: I was faster in the 650s in quali, but I knew that Dmitri will be faster in the race even then just because Dmitri was forced to use the mediums in quali due to R8 tyre heating.

In my experience it was the same with the Maserati and Porsche, the Porsche is better than the Maserati in quali trim, but the Maserati tends to be better in race trim, so RSR is a little misleading.


The Porsche is generally better over 1 lap and the Maserati is equal or better over race distance. Depends a bit on the track though.

Sounds about right

Assists don't matter much for most people at the top I guess, I don't remember whether it was with or without. Hard to say for further down the field, but it shouldn't make any appreciable difference for frontrunners other than being marginally more consistent with ABS.

I'm normally ok without abs, but found the maser particularly difficult. Much trickier than the GTE or group C cars. Possibly from running the hard tyres at 26/27C track temps making one side have way more grip than the other, nightmare on the likes of silverstone or any bumpy track. The last 15 - 20 minutes of the earlier no assist races were very tough with the flat spots.

We'll re assess it before the next championship anyway. Should have it figured out by then

 

[Interslice]

Race report...
That was a tough race! The start was really enjoyable. Myself, Han and tim were neck and neck, swapping positions for the first few laps, until it all fell apart for me! Some of the best few laps of racing i've had here quickly became that lonely journey through the green hell!!
Knowing the track in clean air is one thing, following a car length behind the car ahead is another. I tried to follow tim through flugplatz but ran a touch wide.. not sure of it was the dirty air or just the visibility and timing but clipping the flat cobbled kerb was enough to send me down the straight backwards. Is dirty air a thing in AC? Made another 2 mistakes on that lap and lost 30 seconds to the lads in just one lap. I only had just the pace to keep up but not the close that gap!

It was interesting driving alone for an hour nonetheless, trying to piece together the details of the middle section of the track. Still a few sections to get right.

Thanks to all for racing last night and throughout the championship. Shout out to Han for helping with the organisation and admin side of it. Happy new year to everyone at the club. See ye all at the next one

 

[Kek700]

I have no feeling in my feet, so a car that uses its brakes a lot for its performance, if that is trail braking or just max retardation, ABS is criticle to me.
I can deal with 60,s cars and slower cars, I can get around that because I just reduce brake pressure and adjust brake balance, obviously not using to slow, more adjust entry speed.
So the Mauser without ABS is a no go, so I have to go Porsche.
I also have problems with cars that have no TC, for the same reason.
Especially difficult in old cars because I cannot micro control the accelerator.
I have to wait for the car to let go, then deal with the problem, not the best way, but I have sort of got used to it.

 

[FabianoRL]

Hi all!

Thank you for the champs organization Brian and Han, and Chris and Michael for the overall wins. For me, tons of new knowledge, was really nice to listen the comments after race and see discussions here. Sorry about the eventual mistakes that could've caused issues along the races. I realized that one hour race is the very limit for me to race with VR, after that I feel tired and the Rift S gets hot, which doesn't help at all.

About yesterday, an unknown track for me, so not much to comment about the race other than learning and enjoying the scenery. The Porsche ran with 40/40 liters and I tried to keep original tyres but that was a bad decision. I wasn't fighting for any positions so after a couple of laps I stopped again just for tyres.

Hope to race with you all very soon.

All the best!

Fabiano.

 

[Chris Down]

Knowing the track in clean air is one thing, following a car length behind the car ahead is another. I tried to follow tim through flugplatz but ran a touch wide.. not sure of it was the dirty air or just the visibility and timing but clipping the flat cobbled kerb was enough to send me down the straight backwards. Is dirty air a thing in AC?

Downforce reduction when following cars is implemented and can be seen with the wings app ("DOWNF" at the bottom). Not as much as in a fast open wheeler, but there are still parts of Spa where if you're following very closely you need to lift due to it.

 

[Interslice]

Downforce reduction when following cars is implemented and can be seen with the wings app ("DOWNF" at the bottom). Not as much as in a fast open wheeler, but there are still parts of Spa where if you're following very closely you need to lift due to it.

Cheers chris, will look for the app. Noticed it more in the maser than the 488 for some reason. Plenty of it to spare in the ferrari maybe!

 

[RasmusP]

Knowing the track in clean air is one thing, following a car length behind the car ahead is another.

There's only one thing that helps:
More Nordschleife races!
Maybe we could do some 4 lap races with random grid order?
Not sure if many would like it but it would make Nordschleife races a lot easier, mentally..
Or make the qualy session a few days long so everyone can put in a good clean lap if he wants to
Then copy the order into sgp (I know.. Not great to do that manually.. I guess sgp doesn't support session results to feed as starting orders?)

Is dirty air a thing in AC?

Like Chris said:
Yep, definitely.
It's barely detectable but with the lambo, throughout Flugplatz you have to lift the throttle carefully. Not too fast, not too slow.
You only need to take off the "pushing from the rear tyres" to give more grip to all 4 tyres while slowing transitioning the weight slightly to the front.
If you brake, it will slide off. If you lift too swiftly, you'll slide off. If you don't lift, you'll slide off.

Took me a few hours in 2019 to get this right and the differences were so small that I needed Matteo's throttle telemetry to fix my inputs. I couldn't see it in the replay. Not even when comparing his replay vs my own replay.

So in a corner like that, the very light dirty air implementation in AC still makes a huge difference!

 

[Interslice]

So in a corner like that, the very light dirty air implementation in AC still makes a huge difference!

Ye it's a pretty subtle difference, to the point where I am wondering was it my imagination

 

[HF2000]

Ye it's a pretty subtle difference, to the point where I am wondering was it my imagination

I went off twice on Kottenborn after I got passed by a GT3 and was in its dirty air at top speed. The little loss of downforce/grip on the front caused enough understeer to get the tyres on the right into the grass.

 

[Interslice]

There's only one thing that helps:
More Nordschleife races!
Maybe we could do some 4 lap races with random grid order?
Not sure if many would like it but it would make Nordschleife races a lot easier, mentally..
Or make the qualy session a few days long so everyone can put in a good clean lap if he wants to
Then copy the order into sgp (I know.. Not great to do that manually.. I guess sgp doesn't support session results to feed as starting orders?)

Starting order can be done manually easy enough. Not sure if you can set it to random grid/no qualy etc. Would need to test it.
Ye some more races would be good.. Single class with big numbers on the grid hopefully. The multiclass leaves it even more spaced out than usual..

 

[Interslice]

I went off twice on Kottenborn after I got passed by a GT3 and was in its dirty air at top speed. The little loss of downforce/grip on the front caused enough understeer to get the tyres on the right into the grass.

Ye, looking at the replay that was it. I actually lifted completly off the throttle early enough and it still under steered out to clip the kerb and grass

 

[Interslice]

Context

 

[RasmusP]

Context

Would be interesting to look into the track details and see the grip coefficient of that flat kerb..
The understeer came from dirty air (or you were too excited to lift correctly, like my lambo story above).
The slide however looks weird.. Like the flat kerb would be as slippery as the grass next to it..
I never tried to steer on that kerb. I learnt that when you understeer at Flugplatz, just hit the outside armco and slide around the corner on it. Then go back on the road and continue.

It's one of the few spots where AC feels a bit incorrect for me...

 

[Interslice]

Those kerbs have different grip than the road surface i'm pretty sure. I tested my fair share last night! Ther's a big section of it a brunnchen, i think its called Maybe not grip coef but they feel slightly bumpy like the cobble in fat alphies tracks. They look like cobble bricks too.

Ye it could have been the lift timing of the lift or just my driving for sure. I struggle with a sideway's drift in this car generally. They're a bit out of my comfort zone with the amount of aero grip they have at the best of times.

 

[demetri]

Race trim is very different, just look at quali yesterday: I was faster in the 650s in quali, but I knew that Dmitri will be faster in the race even then just because Dmitri was forced to use the mediums in quali due to R8 tyre heating.

In my experience it was the same with the Maserati and Porsche, the Porsche is better than the Maserati in quali trim, but the Maserati tends to be better in race trim, so RSR is a little misleading.


The Porsche is generally better over 1 lap and the Maserati is equal or better over race distance. Depends a bit on the track though.

Assists don't matter much for most people at the top I guess, I don't remember whether it was with or without. Hard to say for further down the field, but it shouldn't make any appreciable difference for frontrunners other than being marginally more consistent with ABS.

I watched your stream after the race and I don't understand how you can manage to continue to drive with red hot rear tires like it's nothing in the macca. For me in the audi, it usually means more sliding and so even more heat in them which eventually results in a huge drop of grip and a spin if I don't back off and let them cool down.

I probably could've used softs for one lap, but my testing prior to the race showed no time gain overall because I had to go easier in certain parts when the tires got too hot and it was really easy to lose it. Funny that I still managed to botch it pretty bad at Mutkurve and kill my decent flying lap (and also the next one that I qualified with due to the damage acquired). Chickened out and lifted off too much which resulted in snap oversteer that I didn't catch in time. I should've teleported to pits for one more clean attempt, but thought that traffic was going to be an issue, so I decided against it. Good job snatching that pole from me at the last moment!

If the temps were as low as it was originally planned, softs would've worked just fine for the audi though driving on them for 45 minutes in the race would've been a challenge.

WR lap (not perfect but that did it):

 

[Chris Down]

I watched your stream after the race and I don't understand how you can manage to continue to drive with red hot rear tires like it's nothing in the macca. For me in the audi, it usually means more sliding and so even more heat in them which eventually results in a huge drop of grip and a spin if I don't back off and let them cool down.

Only way I found to make it work is to make the setup understeery by default so that the grip difference between front and back is acceptable when overheating. Not a problem I've faced at any other tracks, so not sure if it's the ideal solution, but it worked alright for the softs. Then for the race trim on mediums I can dial out the understeer again.

 

[Chris Down]

Context

I wouldn't trust the replay, they are interpolated. It's entirely possible you were already on the grass when the slide started but it just doesn't have the fine grained data to show it in the replay.

 

[The Almighty Snark]

I wouldn't trust the replay, they are interpolated. It's entirely possible you were already on the grass when the slide started but it just doesn't have the fine grained data to show it in the replay.

Also keep in mind that AC uses a single point to determine grip on a wheel:

PHYSICS - Introducing the 5 point tyre model for ACC!

In modern computing, collision detection is still one of the most resource consuming operations a physics engine has to do. It needs to be very fast,...

www.assettocorsa.net

TLR - Don't touch the kerbs in AC!