F1 Rules Clarification: What is the reference plane?

[747heavy]

just some snippets from the rules:

2.6 Measurements :
All measurements must be made while the car is stationary on a flat horizontal surface

in Bodywork and Dimensions:

Furthermore, infinite precision can be assumed on certain dimensions provided it is clear that such an assumption is not being made in order to circumvent or subvert the intention of the relevant regulation.


All height measurements will be taken normal to and from the reference plane.

skidblock/plank

h) be fixed symmetrically about the car centre line in such a way that no air may pass between it and the surface formed by the parts lying on the reference plane.

[747heavy]

photo of the RBR leica-metrology measurement system.
sorry it´s very small



for the interested, more info can be found here:
http://metrology.leica-geosystems.com/e ... m?cid=5177

[Tozza Mazza]

Hey, I've just began designing a car to 2011 specs, Starting to the floor, I'm completely new to this and the floor regulations are completely unclear! I've made the skid block but what to do for the floor itself? what is the step plane? Where does it go? how far forward does the floor start? confusing regs make no sense!
If someone could clarify the rules relating to the floor itself, it would be much appreciated!

[Formula None]

I agree the FIA regs are absurdly worded and massively confusing. They can't even be bothered to make simple drawings that illustrate most of the articles. FIA/the whole F1 world is like the polar opposite of collectivism, open-source/wiki philosophies. Hyper-proprietary.

An interesting comparison is the ACO LMP regs which read quite easily by comparison and have lots of proper drawings, have a look at them on their website.

[marcush.]

as for the design of the car starting from the design of the plank...you already missed the boat compared with competitive designs I´d fear.

First you need to understand the floor rules.Starting with the reference plane.
And you have to consider the possibilities that all allowances laid out in the
Regs will allow you to achieve the lowest rideheight.

You HAVE to consider the implication of the flat floor starting just behind the front wheels in the light of the tolerance in straightness of the flat floor.
(this follows the lines of why is there an advantage to have the bip stay buckling and let the splitter move upwards ..see splitter proving test FIA)
The plank itself constitutes of more than one piece potentially and there is nowhere stated that the plank has to be absolutely paralell to the reference plane.

I would draw up basic sketches or maybe read the thread somewhere in this forum about flexy wings and floors before drawing up straight boxes in CAD .

[Ciro Pabón]

I think this is an excellent question. It's not in the definitions. You only have this as an approximate definition:
...

I think Drawing 7, page 63 of 63, in the FIA Technical regulations makes it crystal-clear.

Oh, c'mon. You think, you think... Snille och Smak!

I wrote that in 2007... Here you have the same drawing in my carefully conserved 2007 technical regulations: if you see the reference plane you can shot me with your älgstudsare

I named this picture NoReferencePlaneIn2007Regs because... yes, you guessed it: there was no reference plane to be seen at all in any drawing in the 2007 Tech Regulations


For the benefit of the forum I post the latest technical regulations that I have at hand.

March 2006 F1 Technical Regulations
December 2006 F1 Technical Regulations
January 2007 F1 Technical Regulations
December 2005 Draft of 2008 F1 Technical Regulations
April 2007 Draft of 2008 F1 Technical Regulations
February 2008 F1 Technical Regulations
April 2008 Draft of 2009 F1 Technical Regulations
July 2008 Draft of 2009 F1 Technical Regulations
February 2009 F1 Technical Regulations
March 2009 Technical Regulations (showing alterations)
July 2009 Stable 2010 F1 Technical Regulations (Clean)

Please, note that the names are not mine, those are the names, once upon a time, given in FIA site ("clean" regulations? Did they publish dirty ones?).

Now, regarding tolerances, there are a few paragraphs, interred in the Annexes (do not make me give you the links to the annexes... AND NO! I AM NOT YELLING! IT'S JUST THAT I AM SPANIARD! NO, I AM NOT ANGRY EITHER! IT'S CAPSLOCK FRIDAY!).

Beneath the reference plane lies the skid block (or 'plank' as it is better know to Grand Prix fans), which must run from the frontmost point of the reference plane (33cm behind the front wheels) to the rear wheels. It is made out of a material with a specific gravity of between 1.3 and 1.45, and must measure 30cm in width, with a tolerance of 0.2cm. Although it decreases in thickness towards the edges to allow a smooth design, the plank most importantly, when measured through six pre-cut 5cm diameter holes, has a tolerance of just one tenth of a centimetre on its 1cm thickness.

Those who doubt (I know who you are: all of you) remember Belgian GP, 1994.

Schumacher Disqualified Again at Belgian Grand Prix

Now, as for inclined plane of reference, dig (and dig hard!) and you'll find this:

... the surfaces must be 'uniform, solid, hard, continuous, rigid, and impervious'

Now, in Spanish, uniform means uniform... one form. Una forma, Gran 747.

Finally (whew!) I have been in a leave of absence, but once in a while I check and post briefly, no more than 2000 or 3000 words, I swear, and I read around here that the changes for 2011 said something like this:

- The article forbidding team orders (39.1) is deleted. Teams will be reminded that any actions liable to bring the sport into disrepute are dealt with in the same way that FIA deals with any article by Rubython or News of the World...

... blah, blah, blah ...

- A better definition of the reference plane, and reinforcement of bodywork deflection tests, especially at the front of the reference plane

[Just_a_fan]

The point is that you don't have to define the reference plane - the car's designer does that. The reference plane exists purely to act as, you guessed it, a reference plane from which all vertical measurements are taken. Horizontal dimensions for the reference plane are given in order to prevent teams just putting the whole car on the reference plane.

The step plane is defined as 50mm above the reference plane and exists to prevent purely flat floors.

The skid block is defined as an item that is fixed to the surfaces of the car on the reference plane.

The race engineer's job is to get the reference plane (and hence all other horizontal ground facing surfaces) as close to the ground as possible without wearing out the skid block. This give maximum downforce from the floor.

When staring out on a car design, you draw a line on your bit of paper, you name that line the reference plane and then you place all other vertically constrained surfaces relative to that line. You draw another line which is the centre line of the car and place other constrainst relative to that. Finally you decide on the wheelbase and use the clauses that define things relative to the front and rear wheels. You should end up with a few lines and lots of boxes which show you where stuff can go. Then you design the car.