2020 Belgian Grand Prix - Spa-Francorchamps, August 28 - 30

[Just_a_fan]

Watching them go through Pouhon is going to be awesome this year.

Surely they'll be flat in Q3. Last year Leclerc was in 7th with what sounded like a lift on entry to the first part of Pouhon. I wouldn't be surprised if the Mercs are absolutely flat in 7th with a change up to 8th between the first and second parts of the corner.

[Juzh]

Hamilton has only been a few tenths faster than 2019 Ferrari's Q3 time when they had engine cheats. I see a similar trend in Spa.

2020 merc is now a pretty fast car on the straights, unlike 2019 one. This alone will give save them loads of time. If dry I expect a sub 1m42s at minimum, maybe even beating 2018 lap record is not completely out of the picture, but that'll be hard to pull off. Those 2018 cars were insanely planted on this track, quite amazingly so.

Do you mean 2017? If I remember correctly 2018 had a wet qualifying or are you talking about the fastest lap during the race?

2018 q2

Watching them go through Pouhon is going to be awesome this year.

Surely they'll be flat in Q3. Last year Leclerc was in 7th with what sounded like a lift on entry to the first part of Pouhon. I wouldn't be surprised if the Mercs are absolutely flat in 7th with a change up to 8th between the first and second parts of the corner.

Hamilton took puohon flat in 8th gear on both laps in 2018 q2 session (apex speed 291-292 kmh). Vettel who still holds track record tapped the brakes and had slight lift (apex 290 kmh).

Last year they were all much slower as is reflected in laptimes. Cars were faster on straights but lost double that in S2. Leclerc puohon apex 283 kmh, Vettel 280, Hamilton even needed a second lift on the apex (282 kmh), Verstappen 286 kmh.

you can check in this video from 6:02 onwards
https://streamable.com/r5dod

[Just_a_fan]

Hamilton took puohon flat in 8th gear on both laps in 2018 q2 session (apex speed 291-292 kmh). Vettel who still holds track record tapped the brakes and had slight lift (apex 290 kmh).

Last year they were all much slower as is reflected in laptimes. Cars were faster on straights but lost double that in S2. Leclerc puohon apex 283 kmh, Vettel 280, Hamilton even needed a second lift on the apex (282 kmh), Verstappen 286 kmh.

you can check in this video from 6:02 onwards
https://streamable.com/r5dod

Thanks for that Juzh. I felt sure you'd have some evidence one way or the other.

Flat in 8th it will be then, unless the weather intervenes.

[Juzh]

Hamilton took puohon flat in 8th gear on both laps in 2018 q2 session (apex speed 291-292 kmh). Vettel who still holds track record tapped the brakes and had slight lift (apex 290 kmh).

Last year they were all much slower as is reflected in laptimes. Cars were faster on straights but lost double that in S2. Leclerc puohon apex 283 kmh, Vettel 280, Hamilton even needed a second lift on the apex (282 kmh), Verstappen 286 kmh.

you can check in this video from 6:02 onwards
https://streamable.com/r5dod

Thanks for that Juzh. I felt sure you'd have some evidence one way or the other.

Flat in 8th it will be then, unless the weather intervenes.

Forgot to include 2018 laps (open in youtube)

[tangodjango]

2020 merc is now a pretty fast car on the straights, unlike 2019 one. This alone will give save them loads of time. If dry I expect a sub 1m42s at minimum, maybe even beating 2018 lap record is not completely out of the picture, but that'll be hard to pull off. Those 2018 cars were insanely planted on this track, quite amazingly so.

Do you mean 2017? If I remember correctly 2018 had a wet qualifying or are you talking about the fastest lap during the race?

2018 q2

Watching them go through Pouhon is going to be awesome this year.

Surely they'll be flat in Q3. Last year Leclerc was in 7th with what sounded like a lift on entry to the first part of Pouhon. I wouldn't be surprised if the Mercs are absolutely flat in 7th with a change up to 8th between the first and second parts of the corner.

Hamilton took puohon flat in 8th gear on both laps in 2018 q2 session (apex speed 291-292 kmh). Vettel who still holds track record tapped the brakes and had slight lift (apex 290 kmh).

Last year they were all much slower as is reflected in laptimes. Cars were faster on straights but lost double that in S2. Leclerc puohon apex 283 kmh, Vettel 280, Hamilton even needed a second lift on the apex (282 kmh), Verstappen 286 kmh.

you can check in this video from 6:02 onwards
https://streamable.com/r5dod

Oh yeah. Thanks! Completely forgot about q2 being dry in 18 due to the q3 drama.

[godlameroso]

2020 merc is now a pretty fast car on the straights, unlike 2019 one. This alone will give save them loads of time. If dry I expect a sub 1m42s at minimum, maybe even beating 2018 lap record is not completely out of the picture, but that'll be hard to pull off. Those 2018 cars were insanely planted on this track, quite amazingly so.

Do you mean 2017? If I remember correctly 2018 had a wet qualifying or are you talking about the fastest lap during the race?

2018 q2

Watching them go through Pouhon is going to be awesome this year.

Surely they'll be flat in Q3. Last year Leclerc was in 7th with what sounded like a lift on entry to the first part of Pouhon. I wouldn't be surprised if the Mercs are absolutely flat in 7th with a change up to 8th between the first and second parts of the corner.

Hamilton took puohon flat in 8th gear on both laps in 2018 q2 session (apex speed 291-292 kmh). Vettel who still holds track record tapped the brakes and had slight lift (apex 290 kmh).

Last year they were all much slower as is reflected in laptimes. Cars were faster on straights but lost double that in S2. Leclerc puohon apex 283 kmh, Vettel 280, Hamilton even needed a second lift on the apex (282 kmh), Verstappen 286 kmh.

you can check in this video from 6:02 onwards
https://streamable.com/r5dod

Spa also got a fresh coat of tarmac for 2018.

[PlatinumZealot]

Bad bit of napkin maths, discarding decimal precision to build in some pessimism

Current F1 tyre width: 415mm (Pirelli state full-wet is 10mm wider than 405mm-wide slick)
300kph -> m/s = 83m/s

Assuming 100% contact (yeah, we'll get to that...):
total area covered in 1 second: 83m * 0.415m = 34m^2

Assume 10mm tread depth. Can't find any info on this so eyeballing it assuming normal car tyres are ~8mm new and look like tractor tyres.

34m^2 @ 10mm depth = 0.34m^3 -> 340 litres/second

Now, about the 100% contact... the tyre surface that is in contact with the track isn't channeling water; it's the tread that's doing the work. Again, bad eyeballing, let's say 20% of the tyre is tread

340l * 20% = 68 litres/second

Pessimistic with the water volumes and probably optimistic on the tread depth and coverage. Balances out... drop 1mm of tread and that falls to 61 litres/second.

I am not a tyre expert... but I feel it is more complex than that as TimW said.
The depth of water on the surface... (Maybe Pirelli use a standard depth for testing)
The Groove design or capacity I suppose
The contact patch load

Even for the typical pump, the impeller diameter and depth and rpm are not the only factors.
For the typical tyre the grooves also work transversely. That is why they are slanted and there are many of them. Basically it is multiple small pumps taking small bites out of the water that flows towards the contact patch. Also the other thing...Even when pushing water sideways, not all of the water goes under the tyre... some water is simply pushed around it. But at least I can say that your calculation is a good estimate of the amount of water that goes towards the tyre!




You can see where the centre chanels are located. This are an escape for the water being pushed.
You also see that inters had 3mm thread depth, and Full wets 5mm. I think street cars are 8mm.
They estimate the inters at 20 Liters per second, and full wets at 60 L/s. Note this video was from 2011 so yeah things have changed.

[Morteza]

[dans79]

Special helmet for Gasly.

[yelistener]

Spa also got a fresh coat of tarmac for 2018.

Any source for that? I don't remember that. I did a quick search on google and found nothing.

[bosyber]

Hamilton took puohon flat in 8th gear on both laps in 2018 q2 session (apex speed 291-292 kmh). Vettel who still holds track record tapped the brakes and had slight lift (apex 290 kmh).

Last year they were all much slower as is reflected in laptimes. Cars were faster on straights but lost double that in S2. Leclerc puohon apex 283 kmh, Vettel 280, Hamilton even needed a second lift on the apex (282 kmh), Verstappen 286 kmh.

you can check in this video from 6:02 onwards
https://streamable.com/r5dod

Thanks for that Juzh. I felt sure you'd have some evidence one way or the other.

Flat in 8th it will be then, unless the weather intervenes.

Forgot to include 2018 laps (open in youtube)

Great post, cannot rate it in this thread, but deserves seeing, certainly helps me bring back memories of how the track and cars were those years.

[atanatizante]

Bad bit of napkin maths, discarding decimal precision to build in some pessimism

Current F1 tyre width: 415mm (Pirelli state full-wet is 10mm wider than 405mm-wide slick)
300kph -> m/s = 83m/s

Assuming 100% contact (yeah, we'll get to that...):
total area covered in 1 second: 83m * 0.415m = 34m^2

Assume 10mm tread depth. Can't find any info on this so eyeballing it assuming normal car tyres are ~8mm new and look like tractor tyres.

34m^2 @ 10mm depth = 0.34m^3 -> 340 litres/second

Now, about the 100% contact... the tyre surface that is in contact with the track isn't channeling water; it's the tread that's doing the work. Again, bad eyeballing, let's say 20% of the tyre is tread

340l * 20% = 68 litres/second

Pessimistic with the water volumes and probably optimistic on the tread depth and coverage. Balances out... drop 1mm of tread and that falls to 61 litres/second.

I am not a tyre expert... but I feel it is more complex than that as TimW said.
The depth of water on the surface... (Maybe Pirelli use a standard depth for testing)
The Groove design or capacity I suppose
The contact patch load

Even for the typical pump, the impeller diameter and depth and rpm are not the only factors.
For the typical tyre the grooves also work transversely. That is why they are slanted and there are many of them. Basically it is multiple small pumps taking small bites out of the water that flows towards the contact patch. Also the other thing...Even when pushing water sideways, not all of the water goes under the tyre... some water is simply pushed around it. But at least I can say that your calculation is a good estimate of the amount of water that goes towards the tyre!


https://www.youtube.com/watch?v=Pm8JrOztezw

You can see where the centre chanels are located. This are an escape for the water being pushed.
You also see that inters had 3mm thread depth, and Full wets 5mm. I think street cars are 8mm.
They estimate the inters at 20 Liters per second, and full wets at 60 L/s. Note this video was from 2011 so yeah things have changed.

https://www.youtube.com/watch?v=ho7P2Fk-_Y4

...

[atanatizante]

On FP1 Merc drivers divided their workload with HAM trailing a lower DF setup for being 5km/h faster than BOT on the fastest speed trap ...
Thus he was faster in S1&S3 with BOT only in the obvious S2 ...

RBR, as usual, let ALB do the mule work (testing and stuff) and VER just focused only on race pace ...

[search]

On FP1 Merc drivers divided their workload with HAM trailing a lower DF setup for being 5km/h faster than BOT on the fastest speed trap ...
Thus he was faster in S1&S3 with BOT only in the obvious S2 ...

I didn't follow FP1 too closely (so can't say if there may have been another reason), but in the results Bottas is quicker in S3 as well.

[djones]

I'm really confused from the mixed news stories....

Is the new engine mode rule in place?