Honda RA106

Guest · Post 06 Feb 2006, 19:04

The placement of the front (and rear) wings are definitely carefully regulated in the FIA technical regulations.
http://www.fia.com/resources/documents/ ... ATIONS.pdf
But there is "leverage" because the front wing downforce does exert a force vector downwards, and since the pivot is the front axle, a resulting force upwards at the rear of the car. But there are so many components of the car that exert downwards force. In fact, every part pretty well contributes to downforce.
But all those forces are definitely watched by the engineers, and they work very hard not only to achieve maximum downforce at minimal drag, but to "balance" the car. And of course, since they can manually adjust the front wings a bit during the race, this "balance" can be altered, slightly.
But the resulting forces aren't that great, they have minimal impact. I'm quite sure that if the front wing become detached you wouldn't see the rear wing push so hard down that the nose would rise, and the car somersault backwards. Theoratically possible, but we've all seen cars lose the noses and manage to get back to the pits without doing backflips.

Guest · Post 06 Feb 2006, 19:13

dumrick wrote: That translates in the shift forward of the resultant (force resulting in the sum of all) downforce (I don't recall it's abbreviation in english).

Its the aerodynamic center i believe

-R1ceboy

Guest · Post 06 Feb 2006, 19:22

OK this is what I ment

the static equations are
F1.L1 = G.D1 - N2.WB + F2.(WB + L2)
F2.L2 = G.D2 - N1.WB + F1.(WB + L1)

So these are the forces on the wheels:

N1 = G.D2/WB - F2.L2/WB + F1 + F1.L1/WB
N2 = G.D1/WB - F1.L1/WB + F2 + F2.L2/WB

F1.L1 increases N1 but decreases N2.

So my question is, are L1 and L2 tunable parameters or are they regulated?

guest · Post 06 Feb 2006, 19:24

oops, I missed some of the replies

ginsu · Post 07 Feb 2006, 01:30

Its the aerodynamic center i believe

Yes, I know the teams work heavily with the aerodynamic center of pressure in relation to the center of gravity. Because the aerodynamic center is constantly changing in magnitude and location (due to the pitching and rolling motions of the chassis), and the CoG is not changing nearly as much (a little during roll and bouncing off curbs), there must be a constantly changing 'moment' (leverage) caused by aerodynamic center. I'm not sure what they call this moment or truly what it's affects are, but anytime forces are not in line with each other, a moment is created.

Obviously, this means you would want to have the center of pressure between the wheelbase, or otherwise the car would be very unstable at speed.

I'm not certain on this, but when we have seen cars flip (example: Mark Webber at LeMans99) it is usually because they caught the air at a certain angle. I'm wondering if this relates the center of pressure to moving off from between the wheelbase of the car, or if it just reversed the direction of the center of pressure (i.e. worked to make pure lift instead of downforce).

They did tell him not to follow cars too closely and they added front downforce which would suggest that the center of pressure was moving rearward.

However, Mark Webber's #4 became airborne at the Indianapolis corner during Thursday night qualifying session. The car was rebuilt from scratch on Friday, modified for more downforce at the front, and entered in the Saturday morning warm-up. This time, Mark Webber only made it to the Mulsanne kink when the car back-flipped in a spectacular way, this time caught in mid-air on photos. Luckily, neither Webber nor others were injured on either occasion.

Despite the second incident and the awareness of the 1955 Mercedes Le Mans diaster Norbert Haug decided to go ahead and enter the other two cars in the afternoon, with additional modifications and instructions to the drivers not to follow others cars closely over humps.

Mikey_s · Post 07 Feb 2006, 10:25

I'm not an aerodynamicist, but whilst I agree with 'guests' statement

" I'm quite sure that if the front wing become detached you wouldn't see the rear wing push so hard down that the nose would rise, and the car somersault backwards."

It is not correct to say the resulting forces are't that great - when you see a rear wing come off at high speed (and that's when they tend to come off!) the resulant loss of grip on the rear wheels immediately puts the car into a spin - even when one could imagine the momentum of the car should keep it travelling in the same direction. This will be a combination of loss of d/force from the rear and the turning moment from the front wing releiving mass on the rear wheels.

Furthermore, whilst most of the downforce is generated by the underside of the vehicle you can bet your last cent that if they were not necessary the engineers would not fit the wings!

ginsu · Post 09 Mar 2006, 03:23

Look at Honda's pride and joy. Carbon Fiber Transmission Casing.

Those wishbone mounting points look too close together. The wishbones aren't even near parallel. They're moving on totally different arcs. Although, I guess that's something you can play with when you have so little suspension travel.

Also, an awesome detail on the rear upright. Notice how widely spaced the studs are for the brake caliper. Also, radial mounting, too.

Looks like Honda may have rotary dampers from this shot. You can also see the transmission drain plug too. Anybody know what that coating on the driveshafts is?

scarbs · Post 09 Mar 2006, 11:26

If they havent changed the set up since the concept V8 car in testing, Honda actually use linear dampers, they are set inside the casign almost vertically, modern dampers are so small that this isnt a problem with packaging. The drive shafts are Titianium and have a anodized coating, Pankls website has more details (http://www.pankl.com/en/products/racing ... n_systems/)

zac510 · Post 09 Mar 2006, 15:30

Awesome photos, awesome equipment

I'd never noticed how close the casing runs to the C&P (in the diff). Is there any protective casing over this usually?

Is there a third spring in there somewhere? I'd love to see a shot from above.

I don't think the suspension mounting looks too bad considering that it is probably in droop now. But it is odd that the roll centre on the rear would be lowish while generally the front is now high with the zero keel setups. More weight over the rear I suppose.

ginsu · Post 10 Mar 2006, 02:31

I agree, the rear roll centre would probably be above the ground, but pretty low.

Although, I think the roll centre on a zero-keel is on the ground because the arms look nearly parallel (reaction point @ infinity), even though they are drooping. Not absolutely sure though.

The one setup left out of this picture is drooping wishbones.

captainmorgan · Post 10 Mar 2006, 05:14

Guest wrote:OK this is what I ment

the static equations are
F1.L1 = G.D1 - N2.WB + F2.(WB + L2)
F2.L2 = G.D2 - N1.WB + F1.(WB + L1)

So these are the forces on the wheels:

N1 = G.D2/WB - F2.L2/WB + F1 + F1.L1/WB
N2 = G.D1/WB - F1.L1/WB + F2 + F2.L2/WB

F1.L1 increases N1 but decreases N2.

So my question is, are L1 and L2 tunable parameters or are they regulated?

I'm not an engineer, and I haven't seen this kind of notation before. So I am curious, can you provide a name for each variable? I'm guessing WB = wheelbase, but not sure

ginsu · Post 10 Mar 2006, 08:38

Yes, he did not put in a Freebody diagram, so it'll make it difficult for anyone who has never seen the problem. It's essential to have a decent Freebody diag.

I'm not sure, but I think this is what the letters stand for.

F = Force
L = Length
G = Gravitational Force
N = Normal Force
D = Distance

ginsu · Post 17 Mar 2006, 10:20

the static equations are
F1.L1 = G.D1 - N2.WB + F2.(WB + L2)
F2.L2 = G.D2 - N1.WB + F1.(WB + L1)

I just remembered that you cannot use the Static equations unless the body being analysed is completely rigid. This is the first assumption of Statics. Because an F1 car is suspended, these equations would not work properly.