F1 front geometry, why so high RC?

[RicardoGouveia]

Do you know why the F1 cars in the last years have been using this different front suspension geometry?
The static roll center seems to be very high, and I can't figure out why.

I know that there is little roll, but won't the ouside wheel loose -ve camber in corners?

 

[BrianPetersen]

How are you getting that the roll center is high? The upper and lower arms are practically parallel to each other and almost horizontal. That leads to an instant center almost at infinity, for a roll center very close to ground level.

Are you confusing the inclined push-rod that leads to the (inboard) damper/spring unit, for one of the locating arms? That inclined rod doesn't contribute to the roll center. All it does is transfer the motion inboard so that the shock/spring can be mounted inboard and out of the air stream.

 

[GregLocock]

Even if you knew the suspension hardpoints I suggest that the GRC height tells you very little about the practical aspects of the suspension.



Cheers

Greg Locock


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[RicardoGouveia]

It's true, the upper and lowers arms are pratically parallel and this takes the instant center to infinity, but below the ground due to this unnusual inclination. The GRC ends up being pretty high in my opinion.

Here are some examples:

http://www.formula1.com/wi/full/ta_article/ta_article_711.jpg

http://www.roomcars.com/wp-content/uploads/2010/02/2010-Renault-F1-R30-Front-View-508x338.jpg

Maybe the arms have this inclination because of the high nose, geometry being less important then aerodynamic.
A little bit weird, what do you think?

 

[hemipanter]

I have an explanation for this phenomenon, but I am not saying that I'm right on the merits.
One can not evaluate individual elements of an F1 car separated from the rest of the car's design details. If we look at a F1 front so we have a very special design that comes from the aerodynamic aspects. Aerodynamics is a more important factor than the geometry of the suspension, so the A-arms may have to be mounted where there are opportunities. This has the effect that it is extremely important to CGH ports at a low altitude in order to reduce the inconvenience resulting from the failure to have a free hand in the design of the A-arm geometry. We may also face a delicate engineering work with respect to things that camberkompensation, track changes and to keep tire temperatures consistent over the tread with the view of downforce.


In short, we should not look to much at F1 details, it really takes some understanding of the whole car to be able to make an analysis.

Well, that is my opinion concerning this matter....
Goran

 

[NormPeterson]

Maybe there's an attempt going on to get the inside wheel at more favorable camber while cornering or to be less disturbed by driving over the curbs.


Norm

 

[wrightti]

From what I understand the arms are inclined like so because the inboard hard points are required to be up high on the chassis for aerodynamic reasons.

Another reason I just thought of is increase the track variation in bump. This could be advantageous for thermal reasons, and you would never notice this in a simulation unless you had a full thermal tyre model.

I remember thinking that the RC would be very high the first time I saw this design a few years ago, but this was also at about the same time that I realised the geometric roll centre is not the be all and end all of an axle design.

Tim

 

[Yawing]

the front geometry in an F1 is almost completely governed by aero. Are there issues with lateral scrub/camber recovery? not really as the suspension barely moves so hardly an issue. Jacking forces possibly not good for aero hence why the arms are parallel to get the IC of the wheel as long as possible to lower the angle from contact patch to IC point. also you will see the lower point on the upright as high as possible to reduce this effect (and tidy up the air stream as much as possible behind the wing)

you can see the progression from twin keel, single keel, "zero keel" front lower suspension pickup points, especially now with the high nose layout, the arms are being placed higher at the inner points to improve aero.

basically its better to increase the front downforce by compromising with the front geometry and having to tune the balance back a bit (more front downforce means you can live with more load transfer on the front anyway), than to give up overall downforce but have a "nicer" front geometry.

 

[RoterHelm]

Honestly, I do not see a high roll center. The arms are nearly parallel. "Almost". Be cut at a point too far but I think this will be it more or less at ground level.

The shorter the distance between the center of gravity and roll cente the lower the torque.But the center of gravity should never be below the roll center.

Regards, delacf

"Any car which holds together for a whole race is too heavy."