pitstop duration vs laptimes

[misw74]

I'm working on some toy app, to visualise a race, and I see something what I find strange.

Last GP for instance (Brazil 2013) 2013/19 - I'm looking at the data from http://ergast.com/mrd/

When I look at the pitstops let's say pitstops of Webber. He stopped on lap 23, the pitstop duration is 25.012 seconds. I would expect the laptime of lap 24 much longer then laptime of 23. But the difference is only 10,974 s. Even taking into account slower lap 23 ( slower by 4,832 s) it is nowwher close to 25 s.

In other words I cannot find back this lost 25.012 seconds in the laptimes. I'm obviously missing something and I would appreciate if someone could explain it to me.

Best Regards,
Michal

[Markus]

I'm working on some toy app, to visualise a race, and I see something what I find strange.

Last GP for instance (Brazil 2013) 2013/19 - I'm looking at the data from http://ergast.com/mrd/

When I look at the pitstops let's say pitstops of Webber. He stopped on lap 23, the pitstop duration is 25.012 seconds. I would expect the laptime of lap 24 much longer then laptime of 23. But the difference is only 10,974 s. Even taking into account slower lap 23 ( slower by 4,832 s) it is nowwher close to 25 s.

In other words I cannot find back this lost 25.012 seconds in the laptimes. I'm obviously missing something and I would appreciate if someone could explain it to me.

Best Regards,
Michal

You have to take into account that the other drivers still have to drive on the actual track. For example in Monaco the time you lose on the pitstop is quite a small amount of time because you cut away a part of the track. The same applies for Silverstone because you lose four corners when you pit.
I hope you understand what I mean.

[Richard]

I think the pitstop time is from when they cross the white lines that mark the start and end of the speed limit. They are only stationary for a couple of seconds so most of the time is driving slowly along a route that takes them off the circuit.

Don't forget that the lap time is based when the car crosses the start line in the pits, so some of the pit stop is on the inlap and some on the outlap.

So using your example http://ergast.com/api/f1/2013/19/drivers/webber/laps

Lap 22 - 1:18.901
Lap 23 - 1:23.733 - ie 5 sec longer than lap 22 (on old tyres)
Lap 24 - 1:34.707 - ie 18 sec longer than lap 23 (on new tyres)
Lap 25 - 1:16.957

So that shows Webber lost 23 seconds compared to normal laps.

At some circuits the pit lane route is shorter and/or misses a slow corner so the overall lost time is very small. I recall people speculating that the Silverstone pit lane would result in faster lap times!

[piast9]

As Richard says - the basic thing you're missing is the time that takes to drive on the track, during the normal lap between the pit entry and the pit exit.

[misw74]

I think I get it now. They call it pitstop duration which is time between pit entry and pit exit, but it is different than time lost in the pit lane... And this was my assumption.

Actually it is funny, because watching F1 on BBC I pretty sure I have heard them saying few times the pitlane on this track is 20+ s long... Which sounds like, you are losing 20+ s when you go to the pit. And it is 1/2 of it.

Thanks for all quick answers.

[Richard]

When they refer to the overall lost time you'll hear them say a pitstop "costs 20 sec" or "will lose 20sec".

By the way, that site is a fantastic resource, thank for telling us about it.

[Markus]

I think the pitstop time is from when they cross the white lines that mark the start and end of the speed limit. They are only stationary for a couple of seconds so most of the time is driving slowly along a route that takes them off the circuit.

Don't forget that the lap time is based when the car crosses the start line in the pits, so some of the pit stop is on the inlap and some on the outlap.

So using your example http://ergast.com/api/f1/2013/19/drivers/webber/laps

Lap 22 - 1:18.901
Lap 23 - 1:23.733 - ie 5 sec longer than lap 22 (on old tyres)
Lap 24 - 1:34.707 - ie 18 sec longer than lap 23 (on new tyres)
Lap 25 - 1:16.957

So that shows Webber lost 23 seconds compared to normal laps.

At some circuits the pit lane route is shorter and/or misses a slow corner so the overall lost time is very small. I recall people speculating that the Silverstone pit lane would result in faster lap times!

Off topic but wasn´t it at Silverstone one year they had to re-introduce stop and go penalties because you could gain time by going trough the pitlane?

[Richard]

Yes, I think a drive through at Silverstone is potentially quicker than a flying lap.

[misw74]

I've just put the prototype of my app on the web. Please take a look at http://fonescope.appspot.com/