Red Bull RB16

[zibby43]

I'm not sold that Mercedes has the best chassis, the RB16 is faster in slow corners, implying more downforce. Especially in long sweeping corners that don't require much braking.

Slow corner performance isn't really about peak downforce. It's about mechanical grip and setup.

Downforce matters for every single corner except the Lowes hairpin in Monaco. Also don't forget how fast RB has developed their car. It's still entry oversteer, but the rear end is much more consistent than it used to be.

Just to reiterate by putting one key modifier I used in my initial reply in bold, I didn't say that downforce didn't matter at all. Because I agree that it matters, generally.

Back to my original point, the definition what comprises a "slow" corner is important in that context, but generally, with these modern, hybrid-era F1 cars (heavy, wide tires, incredible torque), the differentiating factors in slow-speed corners seem to be mechanical grip, suspension kinematics (together with all sorts of other setup tweaks and changes, including the steering rack, which, as we saw with Merc in Monaco last year/RB this year, can correlate directly with aero performance), the drivability of the PU at low-speeds (i.e., power delivery), etc.

On a side note, @jjn9128, this was a cool video (and cool channel) - thanks for referencing it.

[godlameroso]

Slow corner performance isn't really about peak downforce. It's about mechanical grip and setup.

Downforce matters for every single corner except the Lowes hairpin in Monaco. Also don't forget how fast RB has developed their car. It's still entry oversteer, but the rear end is much more consistent than it used to be.

Just to reiterate by putting one key modifier I used in my initial reply in bold, I didn't say that downforce didn't matter at all. Because I agree that it matters, generally.

Back to my original point, the definition what comprises a "slow" corner is important in that context, but generally, with these modern, hybrid-era F1 cars (heavy, wide tires, incredible torque), the differentiating factors in slow-speed corners seem to be mechanical grip, suspension kinematics (together with all sorts of other setup tweaks and changes, including the steering rack, which, as we saw with Merc in Monaco last year/RB this year, can correlate directly with aero performance), the drivability of the PU at low-speeds (i.e., power delivery), etc.

On a side note, @jjn9128, this was a cool video (and cool channel) - thanks for referencing it.

https://www.youtube.com/watch?v=SLBb61FgRkc

The cars make their own weight in downforce at 110kph, not a lot of corners that aren't downforce dependent. Suspension kinematics are great for keeping the tires in contact with the road, but downforce is what gives you grip, especially at low speeds. Of course things aren't so straight forward, you have to consider the number of corners, that is, places on track where the driver has to slow down, the average speed, how much you lose in the straights vs how much you lose in the corners by the downforce level.

[CLKGTR]

If cars make downforce equal to their own weight (746 kg) at 110 km/h that would mean they generate 4x of their weight in downforce at 220 km/h which is 2984 kg and 9x746kg at 330 km/h which is 6714 kg - is that possible?

[Sieper]

I don't know anything about the numbers but the suction under these cars at speed is enormous. George Russell's car lifted a big round drain cover in Baku once. Or perhaps it was a wheel running over it that actually tripped it loose.

In any case, the forces at speed are clearly incredibly large. You can see the cars twist and strain under he loads in those super slow-mo's they often show.

[jjn9128]

If cars make downforce equal to their own weight (746 kg) at 110 km/h that would mean they generate 4x of their weight in downforce at 220 km/h which is 2984 kg and 9x746kg at 330 km/h which is 6714 kg - is that possible?

I wrote a long response which disappeared somewhere. I'll summarise as I'm on mobile.

I think 110kph is too low. If we take the Kyle engineers number at face value it's 137kph. Willem Toet wrote a post on LinkedIn which suggested Cz~5 which is close but not the same as the KE value. That could be difference between Mercedes and sauber or both hiding the truth a little. But the Toet number gives crossover at 144kph. Assume a mid ground then at 140kph df = dry weight.

[e36jon]

I don't know anything about the numbers but the suction under these cars at speed is enormous. George Russell's car lifted a big round drain cover in Baku once. Or perhaps it was a wheel running over it that actually tripped it loose.

Not arguing that the cars make stupendous downforce. The challenge for most of us, I think, is that we aren't used to thinking of forces applied over areas. In the case of the manhole cover that Russel managed to dislodge you have to think in terms of force times area. Consider a pressure differential of 2 psi applied over the area of a 24" diameter manhole cover with an area of 452 in^2. That's ~900 lbs-force! That manhole cover weighs less than 200 lbs, so of course it was dislodged. Welding them down suddenly makes more sense, yes?

[Bandit1216]

If cars make downforce equal to their own weight (746 kg) at 110 km/h that would mean they generate 4x of their weight in downforce at 220 km/h which is 2984 kg and 9x746kg at 330 km/h which is 6714 kg - is that possible?

Assuming it's exponential to the power of 2. But that's an assumption right? Isn't it as simpel as friction coeff x downforce = G forge?

What is the friction coefficient of soft F1 rubber on a well rubbered hot F1 tarmac? Guess it's closer to 2 than to 1. So about 2 coeff x 2,5 dowforce = 5 G for the fast corners. Not far off I would say.

[Just_a_fan]

If cars make downforce equal to their own weight (746 kg) at 110 km/h that would mean they generate 4x of their weight in downforce at 220 km/h which is 2984 kg and 9x746kg at 330 km/h which is 6714 kg - is that possible?

Assuming it's exponential to the power of 2. But that's an assumption right? Isn't it as simpel as friction coeff x downforce = G forge?

What is the friction coefficient of soft F1 rubber on a well rubbered hot F1 tarmac? Guess it's closer to 2 than to 1. So about 2 coeff x 2,5 dowforce = 5 G for the fast corners. Not far off I would say.

Downforce (and drag) increase with the square of velocity which is what he's suggesting leads to 6714kg at 330km/h.

[CLKGTR]

@Bandit1216

Downforce (and drag) increase with square of velocity so if we know the downforce value for any speed we can approximately calculate the downforce at any other speed without knowing other values.



Where WHF can be represented with a coefficient of lift (cL).

Off course, it isn't that simple as the flow structures are changing with speed (and ability/efficiency of certain elements to produce downforce), but it is useful for general approximations.

[Just_a_fan]

If cars make downforce equal to their own weight (746 kg) at 110 km/h that would mean they generate 4x of their weight in downforce at 220 km/h which is 2984 kg and 9x746kg at 330 km/h which is 6714 kg - is that possible?

I wrote a long response which disappeared somewhere. I'll summarise as I'm on mobile.

I think 110kph is too low. If we take the Kyle engineers number at face value it's 137kph. Willem Toet wrote a post on LinkedIn which suggested Cz~5 which is close but not the same as the KE value. That could be difference between Mercedes and sauber or both hiding the truth a little. But the Toet number gives crossover at 144kph. Assume a mid ground then at 140kph df = dry weight.

Which would give 4x dry weight at 280km/H which seems a bit more likely.

[CLKGTR]

If cars make downforce equal to their own weight (746 kg) at 110 km/h that would mean they generate 4x of their weight in downforce at 220 km/h which is 2984 kg and 9x746kg at 330 km/h which is 6714 kg - is that possible?

I wrote a long response which disappeared somewhere. I'll summarise as I'm on mobile.

I think 110kph is too low. If we take the Kyle engineers number at face value it's 137kph. Willem Toet wrote a post on LinkedIn which suggested Cz~5 which is close but not the same as the KE value. That could be difference between Mercedes and sauber or both hiding the truth a little. But the Toet number gives crossover at 144kph. Assume a mid ground then at 140kph df = dry weight.

I agree that 140 km/h is a more realistic value, 110 km/h is definitely too low even for an F1 car to be able to generate the downforce equal to its own weight.

For 140 km/h it means that they have 3426 kg of downforce at 300 km/h, which sounds more realistic.

[Just_a_fan]

I don't know anything about the numbers but the suction under these cars at speed is enormous. George Russell's car lifted a big round drain cover in Baku once. Or perhaps it was a wheel running over it that actually tripped it loose.

Not arguing that the cars make stupendous downforce. The challenge for most of us, I think, is that we aren't used to thinking of forces applied over areas. In the case of the manhole cover that Russel managed to dislodge you have to think in terms of force times area. Consider a pressure differential of 2 psi applied over the area of a 24" diameter manhole cover with an area of 452 in^2. That's ~900 lbs-force! That manhole cover weighs less than 200 lbs, so of course it was dislodged. Welding them down suddenly makes more sense, yes?

Indeed so. When you look at a Jumbo (747-800) flying, its wings are generating about 1.15 lb/sq in of lift at maximum take off weight. For much of the flight, they'll be generating less than 1 lb/sq in.

(based on a wing area of 5960 sf ft / 858,240 sq in and a maximum take off weight of 987,000 lb (from wikipedia for ease of quick finding)).

This is a simplification, of course, because the lift from an aircraft is more complicated than that, but it gives a reasonable ball park.

[Bandit1216]

If cars make downforce equal to their own weight (746 kg) at 110 km/h that would mean they generate 4x of their weight in downforce at 220 km/h which is 2984 kg and 9x746kg at 330 km/h which is 6714 kg - is that possible?

I wrote a long response which disappeared somewhere. I'll summarise as I'm on mobile.

I think 110kph is too low. If we take the Kyle engineers number at face value it's 137kph. Willem Toet wrote a post on LinkedIn which suggested Cz~5 which is close but not the same as the KE value. That could be difference between Mercedes and sauber or both hiding the truth a little. But the Toet number gives crossover at 144kph. Assume a mid ground then at 140kph df = dry weight.

Which would give 4x dry weight at 280km/H which seems a bit more likely.

Oké. Didn’t know it was square. But that means friction coeff is far less. What’s the fastes real corner atm? Copes, pouchon? Don’t know really. These modern cars demote corners to bended straits at some point. So more like 4 x 1,5 to give 6 G. Did we see 6 G in 2020?

[godlameroso]

In Mugello they were pulling over 5g's in the second sector. The corners are slightly banked so that may have helped. Copse was a 5g corner IIRC.

Even if these cars are making their weight in downforce at 140kph, that means that a good portion of the car's weight is being generated in downforce, the Lowes hairpin is ~40kph, every other corner on the calendar is 60kph or higher.

That means aero is increasing the load of the cars by ~25% at 70kph. Half of the car's weight is being generated by downforce at 100kph/60mph. Or just 20kph above the pitlane speed limit.

[Just_a_fan]

I wonder whether the high rake cars are more effective at low speeds than the low rake cars or vice versa. No idea why they are or even should be, of course.