# Silverstone pit stop strategy

Discussion in 'Presto GP' started by Steeve Fournier, Feb 17, 2013.

1. ### Steeve Fournier

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Here is my results after a lot of laps at silverstone. For now i'm too tired for explanations but i will edt this post tomorrow night probably. All the informations are there but it can be hard to figure them out. Note: all my timings are in seconds, this to make it easier to manipulate formulas in excel.

I average 1.48.555 per lap for 33 minut stint 99L of fuel.
And 1.47.582 per lap in 22 minutes stint, 69L of fuel.
Both exluded the 1st lap

Steeve

Tire wear affect:

I lose 0.066 sec per lap for tire wear. So on lap 19 i am 1.254 sec slower than lap 1 (1 stop strategy) , Compare to 0.858 on lap 13 (2 stop strategy) only talking about tire wear here.

Fuel affect:

Average 0.973 faster each lap for 2 stop = 37.947 sec for 39 laps.

So here are the possibilities :

1 stop strategy = 37.947 lost on track + 47.6 sec pit stop (using Nico numbers which include entrance and exit of pits, but for 100L instead of 92L ) + extra tire wear from lap 13 to 19 and lap 33 to 39 about 2 x 1,386 sec

Total time lost = 37,947 + 47,6 + (2 x 1,386) = 88,319 sec total.

2 stop strategy = No time lost on track + 2 x 40 sec pit stop (again using Nico numbers) + no extra tire wear

Total time lost = 80 sec.

Now you can consider not changing the tires on 1 of the 2 stops and you will save 9.5 sec. Result is you lose only 70.5 sec for stops but you add something around 6 sec. For extra tire wear (that is very theorical and not tested).

My strategy would be 2 stops here. Though there is some trafic to consider and the « theorical » numbers here won't be true if someone is holding you.

Will be intersting to compare what other test drivers find. I will be disapointed if its totally different

Steeve

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2. ### Steeve Fournier

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I post my results data's in the "test driver" thread, but i think it would be better if they are here. Racedepartement doesn't like me to copy/paste from my "WORD" document so i will attached it here.

Nico, maybe you can move my post here?!?!?! Thank you!

Steeve

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3. ### Helder Filipe

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I finish right now a 22min. stint...

My pace was 46, up to 47 low for 2 laps 47.7 for 1 lap and one in 48.0...

1 mistake (1:48.0**) The first lap i did 1:53.1**...

About the wear my worst tyre was at 12.41 of wear in the end of the stint (13Laps) so to go for 1 stop strategy i should do more 6 laps maybe...and maybe, the tyre wear will up to 19 (on XD) but the big question is how much time i'll loose per lap...but i think if we are doing tests and no one find at 100% if 1 stop is better than 2 stops, or vice-versa so i think we have something balanced about the wear/lose time per lap...and it's what we want balance between 1 and 2 stop strategy, right??

Well maybe ill do a 33min. stint, and check how many time i lose per lap...

ps: we are working hard on it, (i dont did the tests like Istanbul, where i applied much more time on it, just because...maybe at Silverstone the lucky side will be most important than all, if we have rain, and if we have rain forget about strategy and wear, everything changes at this moment i think...so we have almost data released and every doubts we will find only after race is finish. (=

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4. ### Helder Filipe

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And tonight i finish my 33min. test...
So i ran all the laps 1 second slow the pace was almost in second 47.5** so i did some math and in my opinion we have, what we wanted to have a balance between 1 and 2 strategys...
If i lost 1 second per lap the race is 39 laps, so in 37 laps let's say i'll lost 37 seconds, in pit stops if i refuel 100L+4Tyres=40,6s ... if i refuel 68L+4Tyres=33,6s x 2 = 67,2s so on track i lost around 37 seconds in pits i'll lost almost the same i think, because my math is without the enter and the exit of pits, even if we do not use pit speed limiter we will lost a little more than 40,6 or 67,2 seconds in pit stop...then after that, nor do I know what strategy to use...

This is my calculations, knowing that im bad at math, i dont know if my "theory" is right!
But i believe that is interesting to read more opinions about it to help someway for the race.

PS: Sorry the delay, my weekend wasn't easy, with fever and vomiting all night Sunday, only tonight i take the wheel again...

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5. ### Nicolai Nicholson

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I wanted to do the test, but this track is not good for me, I am learning all the time and therefore I do not have stable enough times to make a credible test (everytime I do another 22 min I get a little faster).

However, the results from Steeve and Helder is enough for me to understand that the difference between 1 and 2 stop is small enoguh for me to chose based on other criterias (eg. strategy)

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So atm it sounds like tyre wear at x1 ensures us a nice balance between 1 and 2 stopps. So I assume we keep it at x1 for now? (at least the next few races to get more experiences?)

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7. ### Nicolai Nicholson

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That would have been my conclusion as well. However, I think those who were opposed are those who should speak. David was the one that was the most against 1x wear before Istanbul, and he have stayed silent since. Is it because he is unhappy with what have been said? Is it because he now wants 1x wear and see no reason to write a post? And what about Sean? His latest post indicated that he was still very much in favor of 2x wear, is this still the case? Are there others that rather would want 2xwear?

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ive not bothered posting to this as i feel theres too many who are only intrested in racing with minimal practise so choose the easy option, thats just a personal opinion though and obviously real lives dictate how often someone can or is willing to put in any sort of effort.

id still prefer x2 tyre wear, for no other reason than its another challenge for us, weve went backwards with speed lets not go any further backwards, as always though whatever is decided ill put in the time and will be there.

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I can't follow your argumentation David. I mean the discussion about different tyre wear multiplicators wasn't about saving practise time with one option but to find the option which ensures the best balance between 1 and 2 stops. Am I wrong?

After some guys made some more intense stint tests it looks like tyre wear at x1 gives a good balance between 1 and 2 stops. So why should tyre wear at x2 be the bigger challenge?

Well I guess with "another challenge" you mean the higher tyre wear with using x2. But I think we are all very much skilled drivers who are good in handling slippery cars. So wouldn't it be a bigger challenge if you can choose between two theoretical equal strategies and some drivers use strategy "A" and some other drivers use strategy "B"?

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10. ### Nicolai Nicholson

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I feel much better after reading your post as I understand much better now It means the debate is two folded:
1: What it does to 1 vs. 2 vs. 3 stops
2: What it does to the grip/feel of the car throughout the stint

I agree with you that there were many good sides with the wear situation we had with the f1. Driving perfect laps became harder and harder (easier to make mistakes) the more wear you got. If I was not gaining on someone I was following I could think; be patient, watch your tires, he might make some mistakes towards the end of the stint. However, for me this was a valueable spice because everybody seemed to be stuck in the same strategy more or less.

I think we gain more than we lose if we all embrace this new strategy situation, where there are so many possibillities (1, 2 or even possibly 3 stops, change or not change tyres, only change rear tyres, start with lots of fuel and save time in pits etc,). It could lift our race to a new level, and being skilled on worn tyres can still be a valuable asset, depending on your choice of strategy.

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