AC GT3 @ Road Atlanta, Sunday 21st March 2021

[HF2000]

P4, 11 seconds behind the winner. I started 3rd, jumped to P2 right away, on lap 2 caught up with the leader when he had an issue with an oblivious backmarker and lost some momentum. I didn't have good enough run to try to pass him in Schwedenkreuz, but he then made a mistake on braking in Aremberg and had an oversteer moment, so me and the next guy passed him. I kept the lead for a minute and then stupidly misshifted into 2nd in Metzgesfeld , went 90 degrees sideways , got passed by 3 cars and ended up in 4th. P5 and the rest were much slower and already many seconds behind, so they weren't even a distant threat, but it took too much time to get back on the track, so there went my podium hopes.

The guy who eventually won the race didn't even qualify and started in the middle. His practice time was 7 seconds faster than mine, same for the best race laps. I'm not sure if I would've been able to keep the lead even if I didn't make that mistake, he was very good .

It looks like my "brilliant" idea of running with maxed out tire pressures to reduce rolling resistance was actually a bad one. I did have noticeable straight speed advantage, but also had to scrub too much speed in slower corners due to low grip, so the end result was likely worse.

After the race, I tired to do Sabine's hotlap with lower than max pressures (+5 psi to default) and managed to improve my time quite a bit in the same conditions (+20C air, +30C track, 100% grip, 24L of fuel in the tank):

This van is so down on the power that it makes it the ultimate momentum car. And I think those clips of passing motorbikes and sport cars were staged, nobody's that slow.

A backmarker????!!!

 

[Kek700]

@demetri

It looks like my "brilliant" idea of running with maxed out tire pressures to reduce rolling resistance was actually a bad one. I did have a noticeable straight speed advantage but also had to scrub too much speed in slower corners due to low grip, so the end result was likely worse.

I too thought it was a winner too, put tyre pressures at +5 psi all around which should have given the minimum rolling resistance.


Took 5 seconds off my lap time with the correct pressures.

 

[Kek700]

Has anyone got a replay, I only managed half a lap, so I do not have one.

 

[RasmusP]

It looks like my "brilliant" idea of running with maxed out tire pressures to reduce rolling resistance was actually a bad one. I did have noticeable straight speed advantage, but also had to scrub too much speed in slower corners due to low grip, so the end result was likely worse.

I too thought it was a winner too, put tyre pressures at +5 psi all around which should have given the minimum rolling resistance.


Took 5 seconds off my lap time with the correct pressures.

I've seen some graphs about the tire press vs grip formulas/equations in AC.
It drops pretty massively so I always go for the closest to 0.0 in sidekick for the important parts.
Rolling resistance and temperature are almost never worth it...

Afaik that's one of the few things where AC isn't that accurately replicating real life.

 

[demetri]

I've seen some graphs about the tire press vs grip formulas/equations in AC.
It drops pretty massively so I always go for the closest to 0.0 in sidekick for the important parts.
Rolling resistance and temperature are almost never worth it...

Afaik that's one of the few things where AC isn't that accurately replicating real life.

Well, my thought was that the car is mostly bhp-limited, not grip-limited, and takes most of the corners flatout, so doing anything I could to reduce resistance (I couldn't tape off every crevice and roll a draft car ahead like they did for the record TG lap, so I could only work with the tires) would be beneficial. I was wrong, those few corners where grip still mattered outweighted that. But with max pressures I got 1-2 km/h higher top speeds on long straights compared to default, so passing me in a race if I didn't make a mistake could be a problem.

@Kek700 , did you use default main gear or the shorter one?

 

[demetri]

Has anyone got a replay, I only managed half a lap, so I do not have one.

Here you go:

Dropbox

www.dropbox.com

 

[demetri]

A backmarker????!!!

Yeah, and on lap 2. I believe someone might have teleported to the pits (damage was 100%, so it was easy to destroy the car) and started over.

 

[Kek700]

@demetri
The 122 mph gear set was faster, but overall I found the 135mph gears set was overall quicker if that makes any sense.
Thank you so much for the replay, I teleported back to the pits, went out, got even more confused Than I normally am, then threw the towel in.

 

[demetri]

@demetri
The 122 mph gear set was faster, but overall I found the 135mph gears set was overall quicker if that makes any sense.
Thank you so much for the replay, I teleported back to the pits, went out, got even more confused Than I normally am, then threw the towel in.

Yeah, I found that the shorter set accelerated better up until it ran out of usable revs in 6th gear which happened on every long enough straight. Diesels are weird

 

[uvraver]

P4, 11 seconds behind the winner. I started 3rd, jumped to P2 right away, on lap 2 caught up with the leader when he had an issue with an oblivious backmarker and lost some momentum. I didn't have good enough run to try to pass him in Schwedenkreuz, but he then made a mistake on braking in Aremberg and had an oversteer moment, so me and the next guy passed him. I kept the lead for a minute and then stupidly misshifted into 2nd in Metzgesfeld , went 90 degrees sideways , got passed by 3 cars and ended up in 4th. P5 and the rest were much slower and already many seconds behind, so they weren't even a distant threat, but it took too much time to get back on the track, so there went my podium hopes.

The guy who eventually won the race didn't even qualify and started in the middle. His practice time was 7 seconds faster than mine, same for the best race laps. I'm not sure if I would've been able to keep the lead even if I didn't make that mistake, he was very good .

It looks like my "brilliant" idea of running with maxed out tire pressures to reduce rolling resistance was actually a bad one. I did have noticeable straight speed advantage, but also had to scrub too much speed in slower corners due to low grip, so the end result was likely worse.

After the race, I tired to do Sabine's hotlap with lower than max pressures (+5 psi to default) and managed to improve my time quite a bit in the same conditions (+20C air, +30C track, 100% grip, 24L of fuel in the tank):

This van is so down on the power that it makes it the ultimate momentum car. And I think those clips of passing motorbikes and sport cars were staged, nobody's that slow.

The Sabine lap in a transit would have been during a free for all track period, so plenty of inexperienced drivers on track terrifying themselves.
She did the lap to show Jeremy Clarkson what a pussy he was being not cracking 10 mins in a Jag. And he was trying all day to do so.
Clarkson is a very good driver , but driving on a track like the Nordscheilfe in real life is proper scarry.
Riding a motorbike at 100% on this track is not for normal, death fearing type.
Cracking 10 mins means 80mph average speed on a twisty forest road.

Sabine is in a different league on this track:
Watch this first lap in the wet in a proper GT3 race in a 911 GT3

She is passing real racers as though they were Sunday drivers
last[I think] to 3rd passing dozens of full power racing cars.
RIP Sabine Schmitz

 

[demetri]

Bridge to gantry is 19.1 km, so 10 minutes is closer to 70 mph though. Still pretty fast for an underpowered two-ton brick.

To his excuse, Jeremy said he didn't know the track at all. And remember, he probably didn't have a luxury of learning it in a sim that we have now. This track is mostly about experience (and also big balls in real life, of course). I think I did maybe fifty or even close to a hundred laps (with multiple crashes that you're not allowed to have in real life) before I could say that I just memorized all the corners and only after that was I able to work on how to approach each of them and finding the limits. That took me weeks, imagine how much time (and $$$) it would've been if it was for real. No wonder a very talented gal with 15K laps under her belt could kick some ass there.

 

[Kek700]

Not that what I am about to say is of any interest to man nor beast. I just ran your replay Dmitry, spotted the winner just in front of me during my half lap gallop, thought he looks quick. I did my best to catch up, but although he was always held up, there was always one or two vans in my way, ironically because of that I made a rash decision that cost me taking that idea further. It was not until the replay I saw that he was the eventual winner. He was a quick lad, I hoped to use him to get past other vans and a tow.
Funny thing racing, best laid plans of mice and men usually end up as nought.
I was not expecting the 100% damage, that did not help either.