# Stint Calculator (Google Sheets)

#### Giovaneveterano

Hi boys! I created a spreadsheet using Google Sheets that calculates the optimum race strategy according to fuel levels and tyre wear. It's not black magic, but it requires a tiny bit of time to fully understand it. I just feel like I have to share my work with you as I love this community.
You can get it from this link:

Copy into your Google Drive
The first and the most important step you have to take it’s to make sure you’re not editing the public release of the sheet. Other people may be online working on the same file at once and get in the way of each other. By copying the Google Sheet on your Drive, you’re sure no one else can edit it. You can still view and edit the sheet even if you haven’t a Google Account, but I highly recommend avoiding it.

Copy into your Google Drive by: File > Create a copy

Items Description
The whole interface is divided into 4 different tabs: Race, Fuel, Tyres and Pitboard; with a total of 7 editable cells, each of these highlighted with a small black triangle in the upper-right corner.
A brief explanation of each cell is shown by hovering the mouse over it and it’s reported here for clarification purposes.

RACE
• Race Length: in minutes. The software can calculate the strategy for VERY long races, but only the first 150 laps are shown, as the Pitboard repeats itself at some point.
• Laptime: in seconds. Expected average laptime in race conditions. Use comma as a decimal separator.
• Estimated Laps: the total amount of laps are estimated based on your average race pace and the race length. The white flag is supposed to be shown only when there is no time left.
FUEL
• Tank Size: tank capacity, or your starting fuel, if you don't need to stop for refueling.
• Fuel/Lap: amount of fuel consumed every lap. It can be set in Litres, kg or Gallons. Use comma as a decimal separator.
• Fuel Window: In this fuel window, the number of refuels doesn't change. A consumption lower than that means less pit-stops, more otherwise.
TYRES
• Tyre Wear: you can enable or disable tyre wear by using this toggle.
• Wear/Lap: the amount of tread used per lap. It can be an average value on 4 wheels or the lowest one, based on your personal taste.
• Strategy: aggressive strategy tends to change tyres more often, while Conservative keeps them on longer. Normal is in between.
PITBOARD
• Lap: the calculations predicted that you’ll need to box at the end of this lap.
• Elapsed Time: the elapsed time from the beginning of the race when you stop. Useful to plan driver’s swaps during endurance races.
• n° of pits: the total amount of pits predicted to complete the race, even if the pitboard can only show the first seven pit-stops.

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#### Giovaneveterano

This is awesome, thank you! Are you still working on this?
Yes, definitely.

#### thec0wg0d

Ciao! The file looks amazing! the only issue i have is that when i open the link, i'm only able to see 3 sheet: Stint Calculator, Aero, Gears, while in your screens there are a lot more, like, "Issue Solver" or the "advanced pace calculator".. is there a way the have them too?
Thank you!

#### K3nrgy

Yes, seeing the same, also race time can't go above 3 hours.

#### Giovaneveterano

Updated to the latest version: new algorithm and a few bug fixes. Thanks for the feedback. Keep improving!

#### Vincent.C

##### Another WEC driver !
Thanks for it, I will try this stuff

#### Patrick Wanst

Great calculator, but i can't change tyre wear to mm? Or is it percantage only?

#### Giovaneveterano

Great calculator, but i can't change tyre wear to mm? Or is it percantage only?
% only, as a few people got confused by inserting the tread width of 3mm.

Example to get the percentage in ACC:
stint run: 10 laps
tread after the stint: 2.7mm
new tread: 3mm

(3 - 2.7)/3 = 10% on the stint = 1% per lap

#### raceman123321

Where can I find the link for the calculator? The link in your initial post is not working

#### JOSE2K2

Thanks for this amazing job

#### Giovaneveterano

Where can I find the link for the calculator? The link in your initial post is not working
Fixed.

#### ElRaffo90

why does the program put you full of fuel at the start?

#### Giovaneveterano

• Added a warning if any cell has been left empty for whatever reason.
• Adjusted the Strategy tab slightly:
Aggressive: 2.0mm (67%) of minimum tread remaining.
Normal: 1.5mm (50%) of minimum tread remaining.
Conservative: 1.0mm (33%) of minimum tread remaining.
• Slightly updated the Est. Laps algorithm.
I did a 4h race last saturday and it predicted the number of laps with absolute precision.

why does the program put you full of fuel at the start?
It doesn't all the time. It shows the suggested starting fuel when you don't need to grid on full tank.

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#### JOSE2K2

Could the time lost in the pits be added to make the calculation better of the laps? Thanks in advance

#### Giovaneveterano

Could the time lost in the pits be added to make the calculation better of the laps? Thanks in advance
It's added already. You can see how the Est. Laps changes on longer races when you enable/disable the tyre wear checkbox or the fuel/lap. And it works pretty smart.

#### JOSE2K2

It's added already. You can see how the Est. Laps changes on longer races when you enable/disable the tyre wear checkbox or the fuel/lap. And it works pretty smart.
Thanks mate i go check now!

#### Giovaneveterano

Here's an example where you don't need to start on full tank.
3h of Spa with GT3 cars (data inserted has no real meanining).

As you can see the tyre wear is quite high: the strategy is tyre-limited, as the car can complete 31 laps on full tank, but it needs to change tyres every 24.
So the first pit-stop is planned at lap 24 even if there are still 7 laps of fuel left.

The Stint Calculator then proceed to suggest the minimum amount of starting fuel needed to complete the first stint of 24 laps. In this case: 94L. Then allocate the remaining fuel to add to the following refuelings.

It's not a mandatory starting fuel, but just a suggestion. You can still choose to start on full tank and refuel less at the pitstops.

#### Megalodon78

you should add the formation lap and the related low fuel consumption;you should also consider to reduce the race laps considering various the pitstops time

#### Giovaneveterano

you should add the formation lap and the related low fuel consumption;you should also consider to reduce the race laps considering various the pitstops time
It does both.

#### Megalodon78

It does both.
i don0t see the cellto put the pitstop time,do i see an old version?

#### Giovaneveterano

i don0t see the cellto put the pitstop time,do i see an old version?
Most of the cells are hidden and working in the background to provide the best user experience: the refueling speed is one of them. I could show it on screen as editable value, but it definitely adds complexity to the UI and nothing to the strategy.

At the moment I'm using 2.5L/s as refueling speed, 20s for tyre change and 30s as pit lane driving time.

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