Tomba, any insight into the new Mclaren Floor cutouts, etc??

[TauToadmiester]

Tomba, I assume you have seen the news post on this, do you have any insight into how this will increase the efficiency of airflow to the rear wing? Also, any reasons why it is not almost immediately more effective than what other teams are doing and if reality is not proving out what was seen in CFD/wind tunnel?

If you find a more revealing photo of the actually changes to floor and body that would be great as well!

Thanks for any clarifications!

[xpensive]

When there is already one McLaren developmemt thread on the chart, there is really no need to start another one.

[Nealio]

I have seen several photos of the area aft the floor cut-out on the MP4-24. The aero rules state that the floor must be flat and yet this floor area just in front of the rear tire is elevated above the level of the floor. This quadrilateral area has a kick-up at the trailing edge and appear to curve upward at it's leading edge as well creating a wing profile in effect. Isn't this illegal?

[scarbs]

There is a radius rule to allow this curled edge on the cut out

[Nealio]

The 2009 Tech rules state:
3.12 Bodywork facing the ground :
3.12.1 All sprung parts of the car situated from 330mm behind the front wheel centre line to the rear wheel centre
line, and which are visible from underneath, must form surfaces which lie on one of two parallel planes, the
reference plane or the step plane. This does not apply to any parts of rear view mirrors which are visible,
provided each of these areas does not exceed 12000mm2 when projected to a horizontal plane above the
car, or to any parts of the panels referred to in Article 15.4.7.
The step plane must be 50mm above the reference plane.

The quadrilateral area on the MP4-24 directly before the rear tire is higher than the rest of the step plane and is therefore illegal.

[scarbs]

From the Hi Res pictures I've seen I dont think it is. The radius applied to the edge nearest the rear wheel makes it look higher...

3.12.4 The peripheries of the surfaces lying on the reference and step planes may be curved upwards with maximum radii of 25mm and 50mm respectively. Where the vertical transition meets the surfaces on the step plane a radius, no greater than 25mm, is permitted.

3.12.6 To help overcome any possible manufacturing problems, and not to permit any design which may contravene any part of these regulations, dimensional tolerances are permitted on bodywork situated between a point lying 330mm behind the front wheel centre line and the rear wheel centre line. A vertical tolerance of +/- 5mm is permissible across the surfaces lying on the reference and step planes and a horizontal tolerance of 5mm is permitted when assessing whether a surface is visible from beneath the car

[mep]

I think it is not so important to discuss weather it is legal or not.
As long as they run it and nobody (FIA/other teams) complain about it you can take it as a legal device.


More interesting is what it does and how it works.
Until now I had the impression that the teams want to seal the floor against air from outside.
That’s what they did with the skirts in earlier days and with the rounded side pots these days.
But now it looks like they are going in another direction.

When there is already one McLaren development thread on the chart, there is really no need to start another one

Oh I think there is because this whole diffuser stuff could be far more complex than you expect it to be and it is not good to discuss it in a general threat with all the spam there.

[Nealio]

'A vertical tolerance of +/- 5mm is permissible across the surfaces lying on the reference and step planes'

Doesn't this apply to the relationship between the two planes? Rather then a difference in the levels on the step plane alone.

I'm afraid I don't have detailed-enough photos to measure the height difference. And I concede that if the other teams don't challenge it that it may be legal.

[imightbewrong]

here is a good picture of that lip on the floor edge

[ISLAMATRON]

never noticed those exhausts below the rear wheel front lower wishbone mounting point... new?

[kilcoo316]

(1)how this will increase the efficiency of airflow to the rear wing?

(2)Also, any reasons why it is not almost immediately more effective than what other teams are doing and if reality is not proving out what was seen in CFD/wind tunnel?

Addressing the two points in turn

(1) It won't affect the rear wing. It will affect the underfloor/diffuser.

The idea behind it is to use the blockage formed by the wheel, and where the stagnation point of a rotating wheel lies to force the wake of this 'wing' up and thus generate a bound vortex of sorts... this will in turn generate downforce.



(2) That is the big question. Is it more effective than a conventional flat floor? I don't *believe* so - but I have absolutely nothing to back that up, and short of having someone on here that has simulated it or seen the wind tunnel results, none of us can say with any certainty...

Even with simulations or CFD predictions... we still may not be able to say if its effects on track are positive or not.