F1 Steering Rack, a closer look

All that has to do with the power train, gearbox, clutch, fuels and lubricants, etc. Generally the mechanical side of Formula One.
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Stu
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Re: F1 Steering Rack, a closer look

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Excellent study, incredibly interesting. Do you know what pressure it was designed to be operating at?
Perspective - Understanding that sometimes the truths we cling to depend greatly on our own point of view.

Brian.G
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Re: F1 Steering Rack, a closer look

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Stu wrote:
15 Dec 2021, 22:32
Excellent study, incredibly interesting. Do you know what pressure it was designed to be operating at?
Stu, the last two images in my first post - the ones from Moog - mention the valve can handle upto 4000psi,

Brian,
If you think you cant, you wont, If you think you can, you will

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Stu
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Re: F1 Steering Rack, a closer look

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Brian.G wrote:
21 Dec 2021, 18:44
Stu wrote:
15 Dec 2021, 22:32
Excellent study, incredibly interesting. Do you know what pressure it was designed to be operating at?
Stu, the last two images in my first post - the ones from Moog - mention the valve can handle upto 4000psi,

Brian,
Thank you Brian, I didn’t see that. Return line pressure is quite high too (145psi), interesting that it gives a flow rate with 70 bar pressure drop across the valve.
Perspective - Understanding that sometimes the truths we cling to depend greatly on our own point of view.

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Tim.Wright
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Re: F1 Steering Rack, a closer look

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Brian.G wrote:
21 Dec 2021, 18:44
Stu wrote:
15 Dec 2021, 22:32
Excellent study, incredibly interesting. Do you know what pressure it was designed to be operating at?
Stu, the last two images in my first post - the ones from Moog - mention the valve can handle upto 4000psi,

Brian,
Did you measure the effective piston area?
Not the engineer at Force India

Brian.G
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Re: F1 Steering Rack, a closer look

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Tim, I didn't but I must.

Brian,
If you think you cant, you wont, If you think you can, you will

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PlatinumZealot
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Re: F1 Steering Rack, a closer look

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gruntguru wrote:
07 Dec 2021, 00:19
The system still results in motion loss between steering wheel and rack. How much motion loss will always be a function of spool valve amplification factor.
The motion loss as the pinion centre shifts seems to be the analog to the rotational slack in the road car power steering upper shaft and pinion. It should a tiny fraction a mm I guess so that the system can sense the motion.

Do you think that because of the big tyre walls and relatively low pressures, and lighter in F1 that this slack does not as noticeable as in a heavy road car with stiff sidewalls?
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gruntguru
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Re: F1 Steering Rack, a closer look

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PlatinumZealot wrote:
09 Feb 2022, 17:10
gruntguru wrote:
07 Dec 2021, 00:19
The system still results in motion loss between steering wheel and rack. How much motion loss will always be a function of spool valve amplification factor.
The motion loss as the pinion centre shifts seems to be the analog to the rotational slack in the road car power steering upper shaft and pinion. It should a tiny fraction a mm I guess so that the system can sense the motion.

Do you think that because of the big tyre walls and relatively low pressures, and lighter in F1 that this slack does not as noticeable as in a heavy road car with stiff sidewalls?
Not sure. That factor will certainly change with the coming change in rim diameter.

As I said originally, the ratio of assistance to lost motion is entirely a function of the amplification factor chosen in the spool valve. Increasing that could reduce the motion loss but compromise other metrics - perhaps stability or "steering feel". It wouldn't be difficult to create a system with near-zero motion loss (measure and amplify steering column torque electronically) but the result would almost certainly lack feel and driver feedback.
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Greg Locock
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Re: F1 Steering Rack, a closer look

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Citreon did that way back when, using hydraulic assist and no direct path to the steering wheel. Feedback such as it was by a spring, I think. DIRAVI. https://en.wikipedia.org/wiki/DIRAVI

Tommy Cookers
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Re: F1 Steering Rack, a closer look

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Greg Locock wrote:
10 Feb 2022, 03:20
Citreon did that way back when, using hydraulic assist and no direct path to the steering wheel. Feedback such as it was by a spring, I think. DIRAVI. https://en.wikipedia.org/wiki/DIRAVI
this Citroen system or a similar might have enabled rear wheel steering (even replacing front wheel steering)
which could have had benefits with fwd (or awd) ...
or in F1 ???

but going OT is disrespectful to the OP's endeavours

Brian.G
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Re: F1 Steering Rack, a closer look

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Greg Locock wrote:
10 Feb 2022, 03:20
Citreon did that way back when, using hydraulic assist and no direct path to the steering wheel. Feedback such as it was by a spring, I think. DIRAVI. https://en.wikipedia.org/wiki/DIRAVI
Thats one crazy system Greg...thanks for sharing, took me down a 2hr wormhole - finally understand how it works now :lol: Star to the author of the above wiki piece.

Brian,
If you think you cant, you wont, If you think you can, you will

SteeringWheelGuy
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Re: F1 Steering Rack, a closer look

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Thanks for this GREAT explanation, Brian...absolutely brilliant.

When I invented the PersonaGrip, I had no idea how it would affect race car steering. I've spoken extensively about it at steering conferences in Berlin, Dusseldorf, and Ann Arbor, MI. As engineers, we're not too keen about learning how the human body reacts to proprioceptive inputs and forces. But, I talked about why the purity of the direct connection at the HMI (human-machine interface) with a properly set of molded grips bodes well in the cockpit.

For a properly molded set of grips, EMG tests revealed that the steering effort is less than half. However, more importantly, the driver's ability to read the top of the mu-slip curve with a vastly improved signal-to-noise ratio on the self-aligning torque signal makes the limit feel like a sharp peak in the driver's mind...not some vague, nebulous rounded off horizon. When I first felt it, I was SHOCKED, and turned around and inspected the driving surface.

In turn, this led to years of study on how the human body detects and applies forces.

Now, with both of my patents expired, IndyCar teams are discovering that it's not as easy as it looks to design proper grips on steering wheels that are both safe to use, and eliminate the need for feedback-robbing power steering altogether.

I brought Michael Schumacher's '95 Benetton championship steering wheel, Ser.#159/F1-001, with me when I spoke at the conferences...as you can probably imagine, it was a hit at both of Germany's events.

More recently Fernando, while initially skeptical, enjoyed molding and tuning the grips on Ser.#414/415 wheels himself...they're RE-moldable and can be tuned after testing. In fact, after dialing in the grips on the 2nd day, he played a prank on me at Indy pulling into the pits, then ran up with his finger pointing at my face finally yelling, "Don't touch it! They're perfect!"...the McLaren team enjoyed it...too bad the speed wasn't there that year. He's not done at The Brickyard; not when the Triple Crown's at stake.

Now, with the teams trying it themselves with "mixed results" my business model has changed to training the teams. As such, once they learn the process, PersonaGrip's applications in the garage and on pit road are limited only by the teams' imagination.

Thanks again for a GREAT and absolutely brilliant explanation on how F1 power steering works!