Ferrari F138

[BlackSwan]

They abandoned also the new rear wing, the one used in Silverstone race. It is possible that they are extracting more air from the upper part of the car with respect to the lower part, and this cause the "stall" (or a sort of recirculation at certain speed) of the diffuser?

[Pilatus]

They abandoned also the new rear wing, the one used in Silverstone race. It is possible that they are extracting more air from the upper part of the car with respect to the lower part, and this cause the "stall" (or a sort of recirculation at certain speed) of the diffuser?

http://s23.postimg.org/4kjdj68mj/070.jpg

You ommited the RW endplate cut-out behind DRS flap.

[.poz]

I think that one issue for ferrari at the moment is the stallingof the diffuser at low ride heights.
This could be related to the new shape of the sidewall - contact patch of the tyres; I think maybe in Silverstone ferrari also said officially that they were struggling with stall.

The gray fillets in this picture are in may opinion a quick fix to improve the stalling behaviour of the diffuser:

I don't know if it's because of diffuser stalling but the lack of traction when exiting from low-medium speed corner was evident.

[shelly]

I doubt the diffusers ever completely stall on a car that is still able to stay within the track.

You hit the nail in the head: that's why massa was not able to keep his car on track. Same dynamics as Bahrein 7 years ago

Domenical speking about "first lap car imbalance" gives another hint in that direction, plus the fillets looking provisional on the car

[Crucial_Xtreme]

I doubt the diffusers ever completely stall on a car that is still able to stay within the track.

You hit the nail in the head: that's why massa was not able to keep his car on track. Same dynamics as Bahrein 7 years ago

Domenical speking about "first lap car imbalance" gives another hint in that direction, plus the fillets looking provisional on the car

Diffuser stall is common, its when it stalls in the corners when it's a problem.

[elFranZ]

Sorry but I don't buy the stalling/not stalling diffuser idea.
Massa stopped his engine in 5th gear and was not able to keep it on, so I believe he suffered some diff-locking during the brake phase.
Interesting to note, on five consecutive crashes he was approaching a right-handed corner.

[aral]

Sorry but I don't buy the stalling/not stalling diffuser idea.
Massa stopped his engine in 5th gear and was not able to keep it on, so I believe he suffered some diff-locking during the brake phase.
Interesting to note, on five consecutive crashes he was approaching a right-handed corner.

And on each occasion, his car has speared left! But the fact that he was stuck in fifth, must surely provide a clue to what is happening. He should have been able to knock it out of gear, so maybe there is a hydraulic reason for the problems?

[turbof1]

Is it possible that Massa's abrupt spin as the cause of the gearbox issue?

[beelsebob]

Is it possible that Massa's abrupt spin as the cause of the gearbox issue?

It's far more likely that the reverse is true, that the gearbox went, and something locked on only one side of the car, tipping the car into a spin. I've never seen another driver spin the wrong way out of a corner before even reaching it without there being some sort of mechanical cause.

[Kiril Varbanov]

Really, where did you read that ? I'm struggling to get any kind of good info from Ferrari.

I clicked -1 by mistake, but there's no need of sarcasm.
Diffuser would usually stall at high kick angles - something regulated by rules, or at high speeds and high ride heights.
Shelly was merely expressing an opinion and it's a fact that there have been diffuser modifications. The rear wing also looked like it was producing more downforce than usual compared to Red Bull, for example, for a track like Silverstone.

[ringo]

I doubt the diffusers ever completely stall on a car that is still able to stay within the track.

You hit the nail in the head: that's why massa was not able to keep his car on track. Same dynamics as Bahrein 7 years ago

Domenical speking about "first lap car imbalance" gives another hint in that direction, plus the fillets looking provisional on the car

We need to slow down on these home grown theories.
That theory is not supported by any evidence, and i don't think it should be commonly accepted
The floor and the front wing together make more than 70% of the down force. A stalling diffuser is not something that goes unnoticed.
We would definitely hear drivers talking about fluctuating downforce levels. I've never heard this from any driver, and i've never seen a car looked like it lost a high percentage of it's rear downforce in a corner.
The ferrari is simply too good a car, one that can fight for podiums, for it to be losing majoring of it's downforce randomly in corners.
The thing with diffusers too, is that once they are designed and tested to operate with certain speeds and angles, they simply will operate consistently. There are no moving parts. I'd be shocked if ferrari knowingly place a stalling diffuser on a car. The thing works as tested, it just doesn't behave differently.

[ringo]

Diffuser stall is common, its when it stalls in the corners when it's a problem.

Negative Nico, Negative..

The diffuser has to really have a massive shift in pitch for that to happen; beyond it's designed range of pitch angles.
I buy that it may have varying performance, but i don't agree with stalling of the diffuser.
Show some research papers or something to support the idea. A team wont run a diffuser that is known to stall. It simply would be a wrong application.

[Crucial_Xtreme]

Negative Nico, Negative..

The diffuser has to really have a massive shift in pitch for that to happen; beyond it's designed range of pitch angles.
I buy that it may have varying performance, but i don't agree with stalling of the diffuser.
Show some research papers or something to support the idea. A team wont run a diffuser that is known to stall. It simply would be a wrong application.

Ringo you must also take into context how my comment came about. We were speaking of the modifications on the F138's diffuser during FP. The gray fills point to potential separation of flow thus the modification to the diffuser. The comment said stall is common, it didn't say it's a goal of the teams, unless of course we're talking about Monza.

[Dream Theater]

I think that ringo's opinion is right.
The "stalling diffuser" theory isn't supported by any evidence. You might ask to me why I'm convinced about that too...the answer comes out by reading two recent interviews made to Fernando.

I quote to you some of his words, in italian:

"La Ferrari la vedo bene, le darei un otto, un buon punteggio, perché anche se non siamo i più veloci la nostra è una macchina molto completa."

Here you can find these words:
http://www.omnicorse.it/magazine/29184/ ... -formula-1
http://www.blogf1.it/2013/07/12/alonso- ... -nel-team/

I translate it for you: "I see very well the Ferrari, I would give her an 8, a good score, because even if we're not the fastest our car is a complete car."

A pretty good and strong opinion about F138.
We know that Alonso is well known to say what he really thinks, he's not afraid to say what he says, especially when the car isn't good.
Given that there aren't any proofs about the "stalling diffuser" theory, and this positive opinion about the F138, i think that we should find F138's problems somewhere else.

[Crucial_Xtreme]

I think that ringo's opinion is right.
The "stalling diffuser" theory isn't supported by any evidence. You might ask to me why I'm convinced about that too...the answer comes out by reading two recent interviews made to Fernando.



I translate it for you: "I see very well the Ferrari, I would give her an 8, a good score, because even if we're not the fastest our car is a complete car."

A pretty good and strong opinion about F138.
We know that Alonso is well known to say what he really thinks, he's not afraid to say what he says, especially when the car isn't good.
Given that there aren't any proofs about the "stalling diffuser" theory, and this positive opinion about the F138, i think that we should find F138's problems somewhere else.

As for diffuser stall happening, here is proof from Aero_A, who is F1 Aerodynamicist



Read from bottom to top on this image


Problems in Silverstone and then "on the fly" diffuser modifications in Germany show they were having problems with the diffuser. Was it stall? I can't say for sure obviously but it's not unheard of and confirmed by current F1 Aero Engineer.