Force transmitted through steering wheels in crashes

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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vonk
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Joined: 15 Apr 2010, 04:49
Location: Virginia, USA

Re: Force transmitted through steering wheels in crashes

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autogyro wrote:In short oval racing the steering is relatively low geared or standard road ratio.
With a conventional steering wheel it is the thumbs that take the force.
The force is magnified by the low ratio and the much larger number of turns lock to lock than an F1 car. Power steering is also unusual in short oval racing as steering feel is everything. So there is no hydraulic back feed damping.
Forced feed back from steering would not be a good idea on any racing car.
vonk wrote:Steering feel derives from force feedback. Force feedback depends on the steering ratio. F1 cars have very low ratios, which would produce excessive force feedback to the steering wheel. Some (not all) of that feedback is absorbed by the hydraulic steering assist.
autogyro wrote:We are at crossed purposes vonk.
I totaly agree that feed back is designed into the steering geometry on any performance vehicle to increase the feel for the driver.
I was describing power steering feed back, which is counter (in most cases) to improved driver feel and would increase the force returned to the steering wheel in a crash.
I think we may be using different definitions of what we’re talking about. Here is what I mean in simple terms:

High steering ratio = Several turns of the steering wheel, lock to lock (street car). Low steering wheel force (torque). Power steering mostly for parking.

Low steering ratio = Approximately one turn of the steering wheel, lock to lock (F1 car). High steering wheel force (torque). Steering assist to reduce driver effort.

To give the race car driver a feel of fine variations in lateral tire traction, the steering linkage must be rigid. This requires direct mechanical (non-hydraulic) connections throughout the linkage, with the power assist working in parallel. Of course, front wheel caster is the source of steering feedback. But caster is usually optimized for handling while steering feedback is conformed via linkage geometry and/or power assist.
Techno-Babble = Meaningless use of technical terminology to feign knowledge.

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Rideway
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Joined: 12 Sep 2009, 13:31
Location: UK

Re: Force transmitted through steering wheels in crashes

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vonk wrote:In drivers school they teach:
1) Don’t ever hold on to the steering wheel.
2) Let go of the steering wheel when impact is unavoidable
3) Steering power assist is required precisely because the low steering ratio results in high force feedback from the wheels.
In FIA's document "A driver's guide to safe Motorsport" is stated the following:
Page 16:
If you see an accident coming…
• The less distance there is in which you can accelerate before making contact with
parts of the car, the less hard the blow will be when you do.
• In a lateral or oblique angle crash, if possible move your head and legs to the
impact side (into the headrest or side padding), not away from it.
• In a front or rear end crash, position your head on the rear headrest and, if you are
wearing one, let your frontal head restraint device do its work.
• Leave your hands on the steering wheel but with the thumbs out of it.
• Do not try to resist the impact with muscle tension.

Billzilla
Billzilla
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Joined: 24 May 2011, 01:28

Re: Force transmitted through steering wheels in crashes

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A FWIW gents.
This is the last time I went racing .... until I get the new car ready.
Take a look at the steering wheel after I take it off and throw it onto the bonnet - I did that with my left hand only, it didn't get hit by my helmet. My hand was fine after that, other bits not so fine.

[youtube]http://www.youtube.com/watch?v=gNS3_TzEtlE[/youtube]

Belatti
Belatti
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Joined: 10 Jul 2007, 21:48
Location: Argentina

Re: Force transmitted through steering wheels in crashes

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Was there something wrong after the spin? Why the slow peace?

Did you check backwards before stepping down the car? I have seen a couple of accidents of cars hitting drivers, never forget that... :wink:
"You need great passion, because everything you do with great pleasure, you do well." -Juan Manuel Fangio

"I have no idols. I admire work, dedication and competence." -Ayrton Senna

Billzilla
Billzilla
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Joined: 24 May 2011, 01:28

Re: Force transmitted through steering wheels in crashes

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I think I explain it in the comments for the video on the parent Youtube page - The double spin was so violent that I thought the car was bent, so all I wanted to do was to driver slowly back to the pits, put the car on the trailer, take it home and go right over it for bent stuff and cracks. I got as far as the exit of the next corner before getting hit by Stevie Wonder ...
I got out of the car on the right hand side, against the fence so pretty safe and I didn't want to be stuck in the car in case it started leaking fuel or something else unpleasant for my health.