24h Nürburgring dilemma

[Giulietta73]

3 Race soft pit in 2 stints, refuel when 1/4 fuel is remaining.

This.

But whenever you pit, take on enough fuel to equal the time of the tire change - about 13-14 litres. It will put off the 'big fill' for a long time. Why waste the time just changing the tires?

 

[bryanf]

Yes, I've done it! 162 laps done. Because the AI was so slow in the wet, I managed to gain 40-50 seconds a lap, and I over took the leader with 46 minutes remaining. In the end I was over 3 minutes ahead. It would have been much tougher if it didn't rain. It is all the more rewarding since I didn't resort to cutting chicanes or exploiting bugs. Thanks for all the advice!

 

[evanzo7]

Then rain started to fall at 20:30, and I changed to RS all round, since apparently they are quicker than inters or wets, and the wear rate is extremely slow compared to dry. But now the track is at 100% moisture, and I'm finding it very slippery, so I'm changing to inters.

Because of one of the updates not so long ago the Soft tyres are no longer better in the wet than the Inters and Wet tyres.

 

[eran0004]

bryanf: This might not help you any more since it's turned wet, but the way the pit stops work in this game makes it so racing soft is *always* faster than hard and medium in long races. Even if you have to pit every single lap, the time you gain out on the ring will make up the time you spend in the pit (albeit pretty boring to never get to drive down the s/f straight!).

The reason is because the crew changes tires and refuels at the same time, so you always get 12-13l fuel "for free" while they change tires. Or putting it in another way; If one lap consumes 13l of fuel you get that refill for free when you change tires every lap, while someone who pits every 3rd lap has to refill 39l so he's stationary 3x as long each stop. That means the only time you really "lose" by stopping each lap is how long it takes to drive down pitlane at XX km/h compared to going full speed on the straight. On the ring I think it's about 15s, and you gain a lot more than 15s per lap with RS over RH. If you can stretch softs to two laps it's not even funny.

This is not something I normally recommend, since I think it's unrealistic and takes all the fun out of it, but if you're in a pinch then it's a sure way to gain time compared to finishing on hard tires.

True. I have built a "stint calculator" in MS Excel, based on the tyre data from this excellent thread, and if refueling is not taken into consideration then RM tyres and 2 lap stints are the fastest ones for Nürburgring 24 H, but when the refueling factor is subtracted, RS tyres is a much better choise.

AVG = Average expected lap time over the entire stint, including tyre pit stop (no fuel)
% = Percentage of the Racing Hard tyre time.
Fuel factor = AVG time minus the time you save (roughly 15 seconds) by refueling every time you pit to change tyres. If you pit every lap the saving is 15 seconds per lap; every two laps is 7,5 seconds per lap; every three laps is 5 seconds per lap.

The model is not 100% accurate, as the data it's been built on is collected from a Nissan Calsonic IMPUL GT-R (Super GT) '08 on Nürburgring GP/F. Other cars and other tracks wear tyres differently. Still, it's a rough sketch.

So with the data provided in this thread, he would save 10 seconds per lap by switching from 3 lap stint RH to 2 lap stint RM, fuel not included.
With the fuel factor in mind, the saving would be 14 seconds per lap by switching from 3 lap stint RH to 1 lap stint RS.

 

[Morgoth_666]

Yes, I've done it! 162 laps done. Because the AI was so slow in the wet, I managed to gain 40-50 seconds a lap, and I over took the leader with 46 minutes remaining. In the end I was over 3 minutes ahead. It would have been much tougher if it didn't rain. It is all the more rewarding since I didn't resort to cutting chicanes or exploiting bugs. Thanks for all the advice!

Great to hear, congratulations. Thanks for not leaving us hanging, too.

 

[duncan77]

Because of one of the updates not so long ago the Soft tyres are no longer better in the wet than the Inters and Wet tyres.

Are the inters still better than the wets? I ask because I started this 24 hr race last night in 100% rain and I'm using the inters.

I went to the outside on turn 1 and took first place, and am now lapping about 1 minute faster than the second place AI. If it doesn't dry out at some point this may be quite the grind.

 

[GTP_Monkey]

Are the inters still better than the wets? I ask because I started this 24 hr race last night in 100% rain and I'm using the inters.

I went to the outside on turn 1 and took first place, and am now lapping about 1 minute faster than the second place AI. If it doesn't dry out at some point this may be quite the grind.

Wait till it gets dark, the fun really starts.

 

[bryanf]

Are the inters still better than the wets? I ask because I started this 24 hr race last night in 100% rain and I'm using the inters.

Yes, I can confirm that inters are much better than wets at 100%. Not only that, the tires last much longer, as they lasted longer than a full tank of fuel for me. I could only get 4-5 laps on wets.

I believe the reason why the AI is so slow in the wet is because they use full wets. If it rains for the whole race, you could challenge yourself by running rain tires as well. Be warned that the AI is unreasonably fast when the track starts to dry though. I lost over 10 seconds a lap during this period, which was one of the reasons the race was close for me.

On another note, the R8 race cars' headlights are not as good as some other LMPs and you can't toggle between high and low beam. At times I felt I was driving blind, and relied on my intuition after months of practice. I was at the edge of my seat the whole night!

 

[warpkez]

If I remember correctly, you burn about 25ltrs per lap. I am not sure how the physics engine works, but if fuel weight is factored having half a tank full will save pit time, but also reduce your weight a fraction.

 

[bryanf]

If I remember correctly, you burn about 25ltrs per lap. I am not sure how the physics engine works, but if fuel weight is factored having half a tank full will save pit time, but also reduce your weight a fraction.

The R8 I used only consumed 14 liters a lap. This meant I could go for 7 lap stints on inters (all fuel tanks are 100 liters). In dry conditions I always kept the tank under half full. I'm pretty sure there is a performance benefit for having less fuel, but I don't think anyone has quantified the exact time penalty per liter of additional fuel. The time saved in the pits is obvious, however.

 

[Nissan 200SX]

Which settings do you use as traction control etc, did you tune the suspension set up also etc. ? Why did you set the downforce to a minimum ? IF TC are set to 0 I would not use RS tyres because the risk of wearing them down quick if you do a mistake and spin etc.

 

[bryanf]

Which settings do you use as traction control etc, did you tune the suspension set up also etc. ? Why did you set the downforce to a minimum ? IF TC are set to 0 I would not use RS tyres because the risk of wearing them down quick if you do a mistake and spin etc.

I varied the traction control between 2 and 4 depending on track moisture and tire wear. In addition to the reason you stated for not using TC, it is also unrealistic as all LMPs have some sort of TC installed in reality.

I softened the suspension slightly and made it slightly biased towards understeer with the help of Quicktune. I was looking for a tune that would make the car as drivable as possible, not for raw pace. I set downforce to minimum because I thought it would make for a closer race. It turned out to be a bit too close for my liking.

 

[evanzo7]

Are the inters still better than the wets? I ask because I started this 24 hr race last night in 100% rain and I'm using the inters.

I went to the outside on turn 1 and took first place, and am now lapping about 1 minute faster than the second place AI. If it doesn't dry out at some point this may be quite the grind.

Well I did a race round Suzuka in GT300 cars, I was in the Cusco Impreza.
I used Drys up until 30-35% track water. I then from there used the Inters up until 75-80% where I had to change to wets, car started sliding a bit too much for me.

I suppose it could all be down to what car your in and what track you race on.

 

[Nissan 200SX]

I tried out that car with 0 downforce, and the car are quite "nervous" in handling, but with steering wheel and dry conditions, you should get up to first place again if you know the Nürburgring well. Don't refuel more than necessary between pit stops and I would have used RH tyres. The weather wouldn not likely change back to wet again. Don't overtake unless it's safe and enough space, aka don't take chances and drive be luck, drive consistent.
Also, you can pause the 24H race, practise a little with that car and set up, and do some experiment which option will save you most time RH, RM or RS in some practis round. Then go back to the 24H race.

If you don't know the turn in points for the Nordschleife read this : http://www.bbb-online.de/bmw-power/service/sportauto/nordschleife/nordschleife_1.html

I drive the Nurburgring occasionally for real too ;-)

PS: I assume your 24 race are paused ;-)... I'm a nutcracker lol...