The Big honking holes question

wouterwolfs · 24 Dec 2011, 08:30 (Ref:3003827)

From next year on, the front/rear wheels will have BHH!

What is best position to place the BHH ?
I have enclosed a picture so you can say in which direction( A to the front,
B to the rear or C to middle) the BHH can be placed.
I hope you can tell me something regarding Aërodynamics point of view.

best regards,

Wouter Wolfs

The Badger · 24 Dec 2011, 08:34 (Ref:3003828)

I dont think its up to the team where it is , I would think its a given measurement from a referance point , done that intentionally to avoid possible confussion . At least thats what I would have thought ?

wouterwolfs · 24 Dec 2011, 08:50 (Ref:3003833)

I have read on mulsannescorner:

For 2012, the Big Honking Holes, as of November 3 (modified Technical Bulletin #11-22), are defined as:

At the front they will have a minimum area of 750 cm^2 and a maximum area of 950 cm^2
At the rear they will have a minimum area of 1000 cm^2 and a maximum are of 1200 cm^2
A minimum of 30 mm offset must be maintained between the outer edge of the opening and the outer edge of the fender
As seen from the front or rear, it is permissible to see the tops of the tire
A 20 cm x 25 cm template must be able to pass through the openings front and rear

Only a aera and the template is fixed, not the position?

gwyllion · 24 Dec 2011, 09:02 (Ref:3003837)

Wouter, you can read the full technical regulations at http://private.fia.com/web/fia-publi...(06.12.11).pdf. Go to article 3.4.5 (air extractors) on page 11.

The position of the template is also fixed:

Quote:

These openings must enable the introduction of a rectangular template measuring 20 cm x 25 cm, positioned horizontally and symmetrically in relation to the axis of the axle.

BTW you can see how Oak has implemented the holes on http://www.mulsannescorner.com/newsnov11.html

wouterwolfs · 24 Dec 2011, 09:28 (Ref:3003845)

Thanks I didn't have that.

But then the template is still in the middle of the centerline,
and the template is only 400cm² so with the rest of the area I can still move? Like form/position

I saw the OAK racing car that related this question.

gwyllion · 24 Dec 2011, 09:49 (Ref:3003851)

Indeed, the hole itself does not need be positioned in the middle of the centerline, only the template must.

On this picture of the OAK car the front air extractor seems to be positioned a bit backwards and the rear air extractor appears to be positioned symmetrically around the rear axle.

BTW 20x25 = 500 cm²

The Badger · 24 Dec 2011, 10:26 (Ref:3003858)

Im interested in seeing what happenes to the edge of the hole after a few hours of abuse . I would reckon the edge will become feathered and will eventually require a bodywork change .

MulsanneMike · 24 Dec 2011, 14:10 (Ref:3003909)

3.4.5:
Air extractors

They must comply with Article 3.4.1 above.

Cut-outs above the front and rear wings are obligatory.
Viewed from above they must, above each wheel, for front wheels :
- have a minimum surface area of 750 cm² per wheel
- have a maximum surface area of 950 cm² per wheel
- leave only the tyre visible
Viewed from above they must, above each wheel, for rear wheels :
- have a minimum surface area of 1000 cm² per wheel
- have a maximum surface area of 1200 cm² per wheel
- leave only the tyre visible

gttouring · 24 Dec 2011, 16:47 (Ref:3003957)

What a poor band aid in the regs. And they look dumb . I wonder if a better solution was available
The big honking fin at least was put into graceful use on the audi and Lola coupes. It looks weird in the open and protos

pdxracefan · 24 Dec 2011, 17:58 (Ref:3003981)

Guess I've been under a rock, but what is the reasoning behind the holes? I realize it has to do with aero, but what exactly?

lms · 24 Dec 2011, 20:52 (Ref:3004012)

Quote:

Originally Posted by pdxracefan

Guess I've been under a rock, but what is the reasoning behind the holes? I realize it has to do with aero, but what exactly?

hmm.. good question. Maybe if the bodywork would remain closed, it would help slow down the car while going sideways at high speed (something that ugly bfh does at the rear I guess - and to prevent a rollover type accident)

MulsanneMike · 25 Dec 2011, 02:27 (Ref:3004081)

Quote:

Originally Posted by pdxracefan

Guess I've been under a rock, but what is the reasoning behind the holes? I realize it has to do with aero, but what exactly?

They're to further reduce sudden yaw-flip sensitivity.

**joeb** · 25 Dec 2011, 03:28 (Ref:3004087)

So the holes are only required for P1 right? So why does Oaks new P2 have them? Just to be consistant with their P1?

MulsanneMike · 25 Dec 2011, 03:48 (Ref:3004089)

Quote:

Originally Posted by joeb

So the holes are only required for P1 right? So why does Oaks new P2 have them? Just to be consistant with their P1?

No, LMP1, LMP2, and last I heard, LMPC though that was being debated.

rich07 · 25 Dec 2011, 04:47 (Ref:3004093)

Quote:

Originally Posted by The Badger

Im interested in seeing what happenes to the edge of the hole after a few hours of abuse . I would reckon the edge will become feathered and will eventually require a bodywork change .

I can see that being exploited by someone who knows thier stuff.

MitchZ06 · 25 Dec 2011, 04:57 (Ref:3004094)

Moveable aerodynamic device?

The Badger · 25 Dec 2011, 08:49 (Ref:3004107)

Quote:

Originally Posted by rich07

I can see that being exploited by someone who knows thier stuff.

Not sure how , as the feathering would be caused be wear , which is damage , and you cant control that . But wear can be built in too . Yeah , it will be interesting to see in the long run if this will cause an issue .

Happy Christmas Rich

gregtummer · 25 Dec 2011, 12:16 (Ref:3004134)

Anyone calculated how much time the Big Honkin' Holes will cost/gain a car at Le Mans?

I thought they would slow them down due to aero drag, but some people have said that the air will flow over them anyways and along with less weight, the cars will be faster. (disregarding other technology advances)

Alex Hodgkinson · 25 Dec 2011, 15:47 (Ref:3004154)

Quote:

Originally Posted by gregtummer

Anyone calculated how much time the Big Honkin' Holes will cost/gain a car at Le Mans?

I thought they would slow them down due to aero drag, but some people have said that the air will flow over them anyways and along with less weight, the cars will be faster. (disregarding other technology advances)

The weight of 4 x 200x250mm bits of cored carbon fibre is about 1.6kg..

MitchZ06 · 26 Dec 2011, 02:31 (Ref:3004204)

And all P cars need to weigh 900kg regardless....

TF110 · 28 Dec 2011, 04:36 (Ref:3004708)

With ballast. I'm sure you realize they'll mostly be a good bit lighter and the ballast will be a few pounds heavier this year.

Articus · 10 Feb 2012, 19:47 (Ref:3024231)

The holes are ugly. This is not the 24 hours of LeMons.

those Fenders look nasty.

Simmi · 10 Feb 2012, 22:03 (Ref:3024311)

People will be used to them within literally 30 minutes of racing at Sebring. Who cares!

Speed-King · 10 Feb 2012, 22:04 (Ref:3024312)

Quote:

Originally Posted by Simmi

People will be used to them within literally 30 minutes of racing at Sebring. Who cares!

If you substitute Daytona for Sebring, that's what Grand Am said in 2003...

**Aysedasi** · 10 Feb 2012, 22:38 (Ref:3024331)

It doesn't look so different to me...... If anything is ugly, its those little winglets..... Some better colour-coding though would work wonders.....

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