11 replies to this topic

[Martin]

In a thread in the readers comments section someone has posted a link to a head-on pic of the new Jag: http://www.itv-f1.co.../jagheadonf.jpg

I was surprised by the amount of positive camber on the front wheels. I don't know why I thought it shouldn't be so much but I suppose I thought it would not be quite so obvious. You certainly don't notice it on the telly.

So the questions are: are all cars like this or is it the camera angle? And secondly, I presume camber angle is one of the variables in setting up the car for each race, so at which tracks would you change it and in which way (more or less +ve camber)?

Cheers

Marti

[This message has been edited by Martin (edited 09-15-1999).]

[Elio]

Yes, Martin, most competition cars have negative camber (no positive as you say). Coefficient of friction increases with small negative camber angles, increasing cornering power too.

I hope someboby post a beter answer.

[BADGER]

Martin, the negative camber is to counteract the the deflection of the tire as the car corners. During cornering, the tire wants to roll under which would reduce the contact patch if the tire had 0 camber. By starting with negative camber, the tire deflects and gives the maximum contact area possible.

[tak]

Tire camber is an odd subject. As a previous poster mentioned, when a car corners, the tire deflects laterally, effectively adding postive camber. The car also rolls toward the outside, causing more positive camber. Starting with a little negative camber helps cancel this out. Note that there is a trade off. Running more static negative camber will improve cornering, but will hurt tire wear (inside of the tire wears out), and hurt braking (the inside of the tire does more work--also hurting tire wear!).
A very interesting line of thought here is to compare the camber of the front and rear wheels. Just as increasing negative camber at the front hurts braking, at the back it hurts acceleration. Every high powered car (formula, sports racer or sedan) I've ever seen runs more negetive camber at the front than the rear. What does this tell us about the relative importance of acceleration versus deceleration?

[Kärjistäjä]

That car might be a show piece without the "goods" inside. They might have left it without setting up as they do to the real cars.

[Christiaan]

depends on the track

[Yelnats]

The high camber seen on the front of Race Cars is a compromise between new and worn tires. As the race progesses, heavy braking wears the inner edge of the tire more than the outer due to the negative camber and nose dive effects which can increase this wear.

So additional camber is built in to compensate for this effect and is slightly more than required to compensate for tire roll at the start of the race and somewhat less camber than needed at the end of the tire life.

If the camber is set for ideal traction at the start of the race, the driver can get the impression that his tires have "gone off" because he has worn off the camber under braking and is cornering on the outer edge instead of the cambered surface with a greater loss of grip.

[Christiaan]

Did you see the massive camber angle on the Mclaren in Nurburgring? Ferrari was running virtually none, and the Macs had a very wide angle.

[westendorf]

Indy cars also run a great deal of Neg. camber as well. I think this has alot to with the outdated tyre design mandated by FIA rules. As near as I can tell most of the deflection when these cars jump the curbs
is taken up by the tyres, I [even in slow motion] can not see any real amount of suspension travel other than these tyres moving around alot. Body roll is Zero. It's very curious indeed. Maybe I'll call Bridgestone? or Goodyear?
GO Minardi/AZ!!!

[westendorf]

Sorry, I didn't mean to imply that the FIA has anything to with Indy cars, just that they both run alot of neg. camber. both run very tall section tyres as compared to other high level race cars.
GO Minardi/AZ!!!

[SlowDrivr]

Yelnats- isn't that sort of a circular cause? Braking with negative camber wears the inside more so you need negative camber to compensate? Maybe I misunderstand.

My understanding is you want the tire flat on the road as much as possible. In street cars made into race cars negative camber is used mostly to counteract the large body roll they have and the less than ideal suspensions (ie, Macpherson strut).

In F1 and Indy cars, I would think it is, as someone else stated, mostly to compensate for tire deflection in cornering, since the cars roll so little and have a good suspension (double wishbone).

In both cases though is it a comprise between cornering, braking, and acceleration in varying degrees.

[MvT]

If you remember at Hockenhiem this year, when the cars were going down the straights they were wandering around all over the road, not keeping a straight line. This, I believe is to do withthe fact they were using not much negative camber. The wheels were straight up and down so straight-line speed was maximised (no extra friction). Since they really did not need great amounts of cornering potential, camber was almost zero or slightly negative. Contrast Monaco or Nurburgring where the cars need to be more stable through the corners.