Vettel's Steering Issue

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Zynerji
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Re: Vettel's Steering Issue

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Things like this are curious.

Curious things are investigate by those that dont understand.

Investigated things sometimes reveal wrong doing.

Is this a failure of a part of Ferrari's trick suspension?

Would this make it deemed as unsafe?

???

wuzak
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Re: Vettel's Steering Issue

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Caito wrote:
Mon Jul 31, 2017 2:40 pm
As far as I know, it's a mechanical steering, electrically assisted. Meaning the wheel is connected to a rack/pinion which turns the wheels.
From what I understand the power steering systems are hydraulic.

Fears in the early 2000s were that the electrically assisted systems could aid the driver in knowing when to steer, by having little or no assistance when steering was not desireable or by having more assistance when it was required.

The cars knew where they were on track through transponder and other electronic systems.

Edit: Found the regulation (2013 don't have later on this PC)

10.4.2 Power assisted steering systems may not be electronically controlled or electrically powered. No such system may carry out any function other than reduce the physical effort required to steer the car.

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MrPotatoHead
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Re: Vettel's Steering Issue

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The steering is mechanical with Hydraulic assist.
Very similar to road cars just smaller and lighter of course.

It's possible there was some kind of mechanical damage that caused the car to want to pull tot he left, it is also possible that there was a problem int he steering rack hydraulics itself which caused the normally balanced center position to want to push to the left.

We may never know unless Ferrari decide to tell us.

gruntguru
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Re: Vettel's Steering Issue

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wuzak wrote:
Wed Aug 02, 2017 7:26 am
Caito wrote:
Mon Jul 31, 2017 2:40 pm
As far as I know, it's a mechanical steering, electrically assisted. Meaning the wheel is connected to a rack/pinion which turns the wheels.
From what I understand the power steering systems are hydraulic.

Fears in the early 2000s were that the electrically assisted systems could aid the driver in knowing when to steer, by having little or no assistance when steering was not desireable or by having more assistance when it was required.

The cars knew where they were on track through transponder and other electronic systems.

Edit: Found the regulation (2013 don't have later on this PC)

10.4.2 Power assisted steering systems may not be electronically controlled or electrically powered. No such system may carry out any function other than reduce the physical effort required to steer the car.
Yet another dumb regulation. (No need to specify non-electric.)
je suis charlie

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Mudflap
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Re: Vettel's Steering Issue

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gruntguru wrote:
Thu Aug 03, 2017 4:28 am
wuzak wrote:
Wed Aug 02, 2017 7:26 am
Caito wrote:
Mon Jul 31, 2017 2:40 pm
As far as I know, it's a mechanical steering, electrically assisted. Meaning the wheel is connected to a rack/pinion which turns the wheels.
From what I understand the power steering systems are hydraulic.

Fears in the early 2000s were that the electrically assisted systems could aid the driver in knowing when to steer, by having little or no assistance when steering was not desireable or by having more assistance when it was required.

The cars knew where they were on track through transponder and other electronic systems.

Edit: Found the regulation (2013 don't have later on this PC)

10.4.2 Power assisted steering systems may not be electronically controlled or electrically powered. No such system may carry out any function other than reduce the physical effort required to steer the car.
Yet another dumb regulation. (No need to specify non-electric.)
I think that's to prevent teams from developing fancy computer assisted steering.
How much TQ does it make though?

bigpat
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Re: Vettel's Steering Issue

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It is correct that the cars have electrically assisted power steering, been a common thing for way over a decade.

In my own opinion, the most obvious contributors for his steering being off centre in terms of probability, would be a centering problem with the power steering, toe problem, and less so, a castor problem.

I would think you would need a minimum of 0.75 - 1.0 degree of toe difference ( they run toe out on the front and toe in at the rear) to cause the amount that Vettel experienced. Its a falicy that 0.1 degree would make a difference, cars are normally set up to 0.25 degree increments anyway. With the high sidewall tyres, I would be extremely surprised if any driver or stopwatch could pick it up. Whacking kerbs is an easy to do it, but is normally from a bent steering arm etc. F1 don't use rose joints or threaded adjusters, using shim packers for adjustment s for better installation stiffness, so I doubt its toe...

A difference in castor would result in Vettel actually having to physically turn the wheel to hold the car straight, which he didn't seem to have to do. In Indy Cars ( and any oval track car) the drivers have to turn right to drive in a straight line. A castor split across the front axle helps the cars turn left....

If the mechanics were fiddling with the steering system on the grid then i think it could be that. All shaft connections on the steering are splined and keyed, so can only be fitted one way, except for where the shaft enters the rack, which normally has very fine splines to allow for steering wheel centering...

The fact that it worsened during the race makes me think its the electric power assist that faultered. Typically these systems have a rotary feedback potentiometer, so the system knows how much lock is being applied, hence how much assistance to provide. I assume it is at a minimum value around centre. If the potentiometer has drifted, either do to physically slipping, or misalignment/ calibration on assembly, and /or that it gradually failed or drifted further during the race, it would give a false reading to the control system as to where the centred position is.

That's what I think anyway.....

wuzak
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Re: Vettel's Steering Issue

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bigpat wrote:
Fri Aug 04, 2017 3:13 am
It is correct that the cars have electrically assisted power steering, been a common thing for way over a decade.
No, it is not.

They have power steering, but electronically assisted power steering is not allowed.

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outsid3r
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Re: Vettel's Steering Issue

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The first few laps from VET were all best laps one after the other, so I don't think the issue was there from parcferme. It may have been caused there by a mechanic leaving something loose but it certainly wasn't there from the beginning.

The pace was nowhere near what it should have been, and considering that just before his pitstop RAI did a faster lap on 34(ish) year old tyres than VET did leads me to believe that it was probably a suspension geometry issue not just a mis-alligned center point. Also on the same subject, VET told his pit crew that one of the front tyres looks 'unhealthy' before his pitstop while his teammate with a similar car and tyres clearly had a lot of life left in them. This could have also been caused by a change in geometry.

My two cents would be that the some suspension setting (most probably tow angle) was not tighten up properly in parcferme and the vibrations from the sector 2 chicane (which Ferrari was attacking probably more than any other team) caused the right wheel to open up a bit making the steering sit to the left to make the car go straight.

bigpat
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Vettel's Steering Issue

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Generally if something is left loose, it gets worse. I don't think it's toe movement from kerbs, remember carbon suspension doesn't permanently deform, its intact or in pieces. I think that now in F1, shims/packers are used for suspension adjustment for better installation stiffness.

I think the electric power steering went AWOL. I would think there is a rotary potentiometer to indicate steering angle, to determine the amount of assistance for the amount of steering lock applied. If an adjusting bolt was left untightened then it could give an incorrect reading as to where the centre would be, and could get worse, which is what Vettel reported....

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Tim.Wright
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Re: Vettel's Steering Issue

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A hydraulic assist which conforms to the rule above (forbidding electric actuation or control) would not take any input from the steering position sensor. Hydraulic assists use a spool valve connected to a torsion bar to control the assist pressure. 100% analogue.
Not the engineer at Force India

Zynerji
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Re: Vettel's Steering Issue

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bigpat wrote:
Fri Aug 04, 2017 3:13 am

I would think you would need a minimum of 0.75 - 1.0 degree of toe difference ( they run toe out on the front and toe in at the rear) to cause the amount that Vettel experienced. Its a falicy that 0.1 degree would make a difference, cars are normally set up to 0.25 degree increments anyway.
Why would they do that?

I'm not saying that I am a pro, but I would expect toe in at the front (3-4 degrees) and toe out on the rear (.5-1 degree).
A good friend of mine was a high ranked sim-racer, and that was standard on all formula cars in his garage...

If real world is different, it would be interesting in understanding the math behind it.

wuzak
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Re: Vettel's Steering Issue

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bigpat wrote:
Fri Aug 04, 2017 1:55 pm
I think the electric power steering went AWOL. I would think there is a rotary potentiometer to indicate steering angle, to determine the amount of assistance for the amount of steering lock applied. If an adjusting bolt was left untightened then it could give an incorrect reading as to where the centre would be, and could get worse, which is what Vettel reported....

Electric power steering was definitely AWOL. So much so that it was never installed on the car in the first place.

Please understand, electric power steering has been banned for many years.

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godlameroso
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Re: Vettel's Steering Issue

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Zynerji wrote:
Fri Aug 04, 2017 8:32 pm
bigpat wrote:
Fri Aug 04, 2017 3:13 am

I would think you would need a minimum of 0.75 - 1.0 degree of toe difference ( they run toe out on the front and toe in at the rear) to cause the amount that Vettel experienced. Its a falicy that 0.1 degree would make a difference, cars are normally set up to 0.25 degree increments anyway.
Why would they do that?

I'm not saying that I am a pro, but I would expect toe in at the front (3-4 degrees) and toe out on the rear (.5-1 degree).
A good friend of mine was a high ranked sim-racer, and that was standard on all formula cars in his garage...

If real world is different, it would be interesting in understanding the math behind it.
3-4 degrees of toe in?! That can't be right, 3-4 tenths of a degree maybe I believe, and .5-1 degree out in the rear? How do they keep the car from spinning out?
The height of cultivation is really nothing special. It is merely simplicity; the ability to express the utmost with the minimum. Mr.Lee

Zynerji
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Re: Vettel's Steering Issue

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godlameroso wrote:
Sat Aug 05, 2017 12:22 am
Zynerji wrote:
Fri Aug 04, 2017 8:32 pm
bigpat wrote:
Fri Aug 04, 2017 3:13 am

I would think you would need a minimum of 0.75 - 1.0 degree of toe difference ( they run toe out on the front and toe in at the rear) to cause the amount that Vettel experienced. Its a falicy that 0.1 degree would make a difference, cars are normally set up to 0.25 degree increments anyway.
Why would they do that?

I'm not saying that I am a pro, but I would expect toe in at the front (3-4 degrees) and toe out on the rear (.5-1 degree).
A good friend of mine was a high ranked sim-racer, and that was standard on all formula cars in his garage...

If real world is different, it would be interesting in understanding the math behind it.
3-4 degrees of toe in?! That can't be right, 3-4 tenths of a degree maybe I believe, and .5-1 degree out in the rear? How do they keep the car from spinning out?
I wouldn't expect those to be outrageous numbers. They run 4 degrees of camber as well...

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godlameroso
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Re: Vettel's Steering Issue

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Zynerji wrote:
Sat Aug 05, 2017 1:52 am
godlameroso wrote:
Sat Aug 05, 2017 12:22 am
Zynerji wrote:
Fri Aug 04, 2017 8:32 pm


Why would they do that?

I'm not saying that I am a pro, but I would expect toe in at the front (3-4 degrees) and toe out on the rear (.5-1 degree).
A good friend of mine was a high ranked sim-racer, and that was standard on all formula cars in his garage...

If real world is different, it would be interesting in understanding the math behind it.
3-4 degrees of toe in?! That can't be right, 3-4 tenths of a degree maybe I believe, and .5-1 degree out in the rear? How do they keep the car from spinning out?
I wouldn't expect those to be outrageous numbers. They run 4 degrees of camber as well...
4 degrees of camber isn't too crazy depending on the track, but the toe I feel is, excessive toe makes the tires drag along the ground, you'd only try such extreme angles to keep heat in the tires, and if tire wear isn't an issue. Then again, I'm no alien sim racer so I don't know, maybe such extreme alignment settings work.
The height of cultivation is really nothing special. It is merely simplicity; the ability to express the utmost with the minimum. Mr.Lee