## Scuderia Ferrari SF90

A place to discuss the characteristics of the cars in Formula One, both current as well as historical. Laptimes, driver worshipping and team chatter does not belong here.
DRCorsa
8
Joined: Sat Jan 15, 2011 9:32 am

### Re: Scuderia Ferrari SF90

timbo wrote:
Tue May 14, 2019 7:20 pm
DRCorsa wrote:
Tue May 14, 2019 1:27 pm
Reynolds number is a function of airspeed.
Critical AoA is affected by the separation of the boundary layer, which is a directly dependent on Reynolds number.
Take a look at the following graph. You will see that for higher Reynolds numbers, critical AoA is higher too.
That's the reason why SF90's front wing won't stall at high speeds, but will stall at low speeds.

https://i.ibb.co/LdDr5m4/dPNAs.png
The graph covers many orders of magnitude difference in Re number, this is much much higher than the changes dut to velocity difference between t9 and t10. Also, on the graph, you'd see a highly nonlinear behavior of the Cy/Cx curve, and between some Re number values, the position of maximum may increase or decrease.
Anyway, the effect of the pitch attitude of the car is more important here.
Reynolds number for 0.4m chord length and 75m/s (270kph) = 2.1 x 10.6 --> Critical AoA = 15 degrees
Reynolds number for 0.4m chord length and 28m/s (100kph) = 7.8 x 10.5 --> Critical AoA = 12 degrees

zibby43
194
Joined: Sat Mar 04, 2017 11:16 am

### Re: Scuderia Ferrari SF90

enry86 wrote:
Tue May 14, 2019 11:10 am
Just to sum up a bit and to clarify my own expectations for the rest of the championship ( ), i'd like to dig a bit on the possible impact of the new suspension on the struggles Ferrari is experiencing with its car.

As far as I know, in the first week of preseason testing Ferrari run the new suspension, until the rim/suspension failure which caused Vettel crash. Before switching to the old suspension the car showed an evident squatting behavior during brake and acceleration, which, correct me if I'm wrong, is no more visible on the car now.

So, my question is, it's possible that the change in rake and ride height brought by the new suspension it's a fundamental factor in the aero concept of the car? And that losing it by running the old suspension explains the lack of downforce so evident in the last race?

Am I putting too much faith in this device to solve most of the car problems?
Maybe. What's more, there seems to be quite a bit of debate about whether a new front suspension actually exists. There were no reports of a new suspension being used in testing today (thus far, at least).

Mark Hughes: "Dont know if this new front suspension is mythical or real. All I've heard is chat. Havent heard anything from anyone I know that would know. But yes the idea is that it would allow more rake. If the car's aero concept is based around a rake angle which cannot be achieved with this suspension, then that would offer hope. But I don't know yet if it has or not. That certainly isn't the official line coming from Ferrari."

dans79
193
Joined: Sun Mar 03, 2013 6:33 pm
Location: USA

### Re: Scuderia Ferrari SF90

zibby43 wrote:
Tue May 14, 2019 8:33 pm
Maybe. What's more, there seems to be quite a bit of debate about whether a new front suspension actually exists. There were no reports of a new suspension being used in testing today (thus far, at least).

Mark Hughes: "Dont know if this new front suspension is mythical or real. All I've heard is chat. Havent heard anything from anyone I know that would know. But yes the idea is that it would allow more rake. If the car's aero concept is based around a rake angle which cannot be achieved with this suspension, then that would offer hope. But I don't know yet if it has or not. That certainly isn't the official line coming from Ferrari."
I agree, I haven't seen anything from a reputable news agency about a new suspension that was only used in preseason testing.

TimmTurbo
1
Joined: Fri Feb 03, 2012 12:46 pm
Location: Munich

### Re: Scuderia Ferrari SF90

Still it is pretty obvious that the suspension behavior or "squatting" presumably connected to the cars aero load is not there anymore at least since day one of the actual race season. The theory of a potential benefit using such a system is valid and makes sense to my mind.

Perhaps the crash of Vettel during was linked to that suspension spec or the FIA banned it. However something happened to it. Either way i can understand that Ferrari is not interested discussing this subject in the media.

keroro.90
1
Joined: Mon Jul 01, 2013 8:32 pm

### Re: Scuderia Ferrari SF90

TimmTurbo wrote:
Wed May 15, 2019 8:48 am
Still it is pretty obvious that the suspension behavior or "squatting" presumably connected to the cars aero load is not there anymore at least since day one of the actual race season. The theory of a potential benefit using such a system is valid and makes sense to my mind.

Perhaps the crash of Vettel during was linked to that suspension spec or the FIA banned it. However something happened to it. Either way i can understand that Ferrari is not interested discussing this subject in the media.
Yes, there were some rumors claiming that the failure (Vettel during test) was not related to a rim failure but due to a suspension failure.

keroro.90
1
Joined: Mon Jul 01, 2013 8:32 pm

### Re: Scuderia Ferrari SF90

drsmith7725
0
Joined: Sun Jan 27, 2019 10:00 am
Location: New York

### Re: Scuderia Ferrari SF90

As the car that seeks to be the title challenger to Mercedes, the SF90 from Ferrari shows an evolutionary approach to much of the car, while the work completed to beat the new aero regulations appears far more considered than its rivals.

Mamba
6
Joined: Tue Apr 22, 2014 3:36 pm

### Re: Scuderia Ferrari SF90

GPR -A wrote:
Tue May 14, 2019 6:27 pm
I had said this about Mercedes, when people were critical of their long wheel base, their front 2019 front wing and lower rake concept that, there is no one single silver bullet for building a great car. You can always choose a different concept and make it work. You just need to have a good team who can look beyond the psychological limiting factors and search to evolve their chosen concept. You don't hear Mercedes saying, they chose a wrong concept. In 2017, their car was much criticized for the longer wheel base and the lack of slow corner performance was attributed to it. But for 2018, they retained it and kept improving it.

Ferrari need to have patience and calm heads in their leadership ranks, otherwise, there would be silent panic across and they would falter again. If they allow the pressure from media and fans to push them, then they are doomed.

There would be some circuits where their car might not work and it probably would need a long time to bring right solution to fix it. But there are definitely circuits that would suit the car and they have to aggressively develop their strengths and make the most of it on those circuits. It has taken ages for Mercedes to develop a car that seems to work for every circuit.

Ferrari definitely have resources to turn it around in quick time, but they first have to protect their core designers and engineers from unnecessary external pressure and continue to allow greater freedom to express their ideas and take educated risks. There would definitely light and it's not all gloom.
The difference was that in 2017 they were still doing pretty well. Wins in the first races and plenty podiums. Ferrari currently are second or third best at most depending on the track. Bahrain and perhaps Baku the obvious exceptions here.

But I agree with your statement. They should stay calm and analyse just why things are not working and what can be done to improve the car. Pressure will not help them. Ignore the media calling for heads to roll just because of car failures.

godlameroso
333
Joined: Sat Jan 16, 2010 8:27 pm
Location: Miami FL

### Re: Scuderia Ferrari SF90

Tracks that depend on low speed traction out of corners are going to be difficult for Ferrari then. Which means Silverstone, Suzuka, Monza, Spa, Hockenheim, and Hungary should be good tracks for them.
The height of cultivation is really nothing special. It is merely simplicity; the ability to express the utmost with the minimum. Mr.Lee

LM10
46
Joined: Tue Mar 06, 2018 11:07 pm

### Re: Scuderia Ferrari SF90

godlameroso wrote:
Wed May 15, 2019 6:00 pm
Tracks that depend on low speed traction out of corners are going to be difficult for Ferrari then. Which means Silverstone, Suzuka, Monza, Spa, Hockenheim, and Hungary should be good tracks for them.
Their traction seems to be relatively good, as seen in Bahrain. The problem is the actual mid- to low-speed cornering.

godlameroso
333
Joined: Sat Jan 16, 2010 8:27 pm
Location: Miami FL

### Re: Scuderia Ferrari SF90

LM10 wrote:
Wed May 15, 2019 6:06 pm
godlameroso wrote:
Wed May 15, 2019 6:00 pm
Tracks that depend on low speed traction out of corners are going to be difficult for Ferrari then. Which means Silverstone, Suzuka, Monza, Spa, Hockenheim, and Hungary should be good tracks for them.
Their traction seems to be relatively good, as seen in Bahrain. The problem is the actual mid- to low-speed cornering.
You don't need low speed traction in Bahrain, you need good stability under braking, and power.
The height of cultivation is really nothing special. It is merely simplicity; the ability to express the utmost with the minimum. Mr.Lee

DRCorsa
8
Joined: Sat Jan 15, 2011 9:32 am

### Re: Scuderia Ferrari SF90

godlameroso wrote:
Wed May 15, 2019 6:15 pm
LM10 wrote:
Wed May 15, 2019 6:06 pm
godlameroso wrote:
Wed May 15, 2019 6:00 pm
Tracks that depend on low speed traction out of corners are going to be difficult for Ferrari then. Which means Silverstone, Suzuka, Monza, Spa, Hockenheim, and Hungary should be good tracks for them.
Their traction seems to be relatively good, as seen in Bahrain. The problem is the actual mid- to low-speed cornering.
You don't need low speed traction in Bahrain, you need good stability under braking, and power.

Still in Bahrain, the car was slow through low speed corners.

1
Joined: Sun Apr 21, 2019 4:18 pm

### Re: Scuderia Ferrari SF90

LM10 wrote:
Wed May 15, 2019 6:06 pm
godlameroso wrote:
Wed May 15, 2019 6:00 pm
Tracks that depend on low speed traction out of corners are going to be difficult for Ferrari then. Which means Silverstone, Suzuka, Monza, Spa, Hockenheim, and Hungary should be good tracks for them.
Their traction seems to be relatively good, as seen in Bahrain. The problem is the actual mid- to low-speed cornering.
Vettel after Spain Quali,
"It's not really traction, more overall grip in the slow corner. The slow corners can be quite nasty if you don't have the grip, and then you lose a lot of time."
https://www.gptoday.net/en/news/f1/2474 ... ht-corners

Sevach
789
Joined: Thu Jun 07, 2012 4:00 pm

### Re: Scuderia Ferrari SF90

keroro.90
1
Joined: Mon Jul 01, 2013 8:32 pm

### Re: Scuderia Ferrari SF90

I don't think it's a traction problem, just check the exit from the last chicane during the Q3 lap (comparison Vettel vs Bottas).
Vettel despite being quite slow in the chicane, is able to recover on Bottas and they reach the finish line with more or less the same speed.