Negative camber on tires.

Why do some teams run on such negative camber on their tires?. Ive also read that the cars goes faster this way (The porsche 956 comes to my mind) but why is this?.

I always learned you should have equal temps on the tires across it, so i dont understand this.

camber has cornering applications. there were actually some great shots at silverstone where you could see the cars leaning in to the corners. much like a road car would, but a road car achieves this with suspension travel.

camber does however have a negative impact when used on the drive wheels for the reason you mentioned, not as much contact to the road in some parts of the tire.

if you want an example of how badly it effects the contact patch with the road, go laugh at some moron who has decided that their car is faster lowered. what a crock of s! the camber is so severe (+-5) in some cases of suspension mods that it's useless! i saw a brand new celica slammed to the tits and it couldn't make it up a moderate slope in the snow! haha


Doug

Originally posted by Doug Cormack
if you want an example of how badly it effects the contact patch with the road, go laugh at some moron who has decided that their car is faster lowered. what a crock of s!
Doug

Ermm. What you talking about? I've had my car lowered for a good year and a half, and I've had camber adjustments everytime I get a wheel alignment done. My car has never been better in the handling department than it is now. If you know what you're doing, then do it. If you don't, don't touch it. that's the way I see it when it comes to touching your car in any way, shape or form.

Originally posted by AndreasNystrom
Why do some teams run on such negative camber on their tires?. Ive also read that the cars goes faster this way (The porsche 956 comes to my mind) but why is this?.

I always learned you should have equal temps on the tires across it, so i dont understand this.

Most interesting is the difference on the negative camber run on the F1 cars: Ferrari seems to run about 2.5 - 3 degrees on the RH tyre and perhaps only 1 degree on the left. Given that Silverstone is run clockwise, there must always be more right handers, so I would have expected the settings to be the reverse of what I observed.

VAR1016

Originally posted by Jhope


Ermm. What you talking about? I've had my car lowered for a good year and a half, and I've had camber adjustments everytime I get a wheel alignment done. My car has never been better in the handling department than it is now. If you know what you're doing, then do it. If you don't, don't touch it. that's the way I see it when it comes to touching your car in any way, shape or form.

You're a rare breed, believe it or not. Not quite sure which type of car you own, but it's often necessary to replace the front control arm when you want to correct the camber. Example, my Integra required this to correct the camber in the front.

However, with a fair amount of experimenting I found the fastest combination was stiffer springs at the cars original ride height. Some Honda engineers probably spent a few weeks calculating the suspension setup, and that holds up well.

Believe it or not, 50% of the lowered cars I see are still running stock rims and tires! How ridiculous is that? Rims and tires will give you way more than lowering ever will, I'm sure you'll agree.

Doug

Replacing control arms!

We use much easier things to take care of that, you can use shims or eccentrics or otherwise known as cams, if you want complete full adjustability of your camber/caster you should purchase an adjustable lower control arm, but that is to the extreme.

I myself have never seen any road car even when slammed develop 5 degrees of negative camber, if you figure most lowering kits are 2-3" 4" in the extreme, that is almost in the realm of normal suspension travel on everyday cars... why would engineers put harsh tire wearing angles into their everyday suspensions?

I don't know how a tall car with stiffer springs could possibly be faster than a car with a lower cofg and the same spring rate, its just not really something I can stomach easily.

I hear your point on the stock rims and tires though:) Its funny to see those guys run around with the hub caps off and spray painted semi gloss wheels... however I have no idea how you can get an 18" wheel to be shorter than a 15" wheel?

Still don't have the money for after market rims.

Increased Negative Camber has a couple of effects:

1) The steering responds to changes faster, conversely the car is less directionally stable in a straight line.

2) As the suspension loads up and the car 'leans' in the corner, the camber effectively disappears and as the contact patch grows on the outside tyre, grip increases, eliminating understeer, as it's only of benefit on the front wheels.

Interestingly (for some!) Prewar racing cars used to run loads of positive camber on the front wheels. This was to counter the effects of axle tramp as independent suspension was a pipedream then - they were still on transverse leaf springs...

Originally posted by Fizzicist
Increased Negative Camber has a couple of effects:

1) The steering responds to changes faster, conversely the car is less directionally stable in a straight line.

2) As the suspension loads up and the car 'leans' in the corner, the camber effectively disappears and as the contact patch grows on the outside tyre, grip increases, eliminating understeer, as it's only of benefit on the front wheels.

Interestingly (for some!) Prewar racing cars used to run loads of positive camber on the front wheels. This was to counter the effects of axle tramp as independent suspension was a pipedream then - they were still on transverse leaf springs...

That's a nice summary, but I had assumed that positive camber was used on pre-war (and some post-war) cars because of the tyre construction in those days.

As for transverse leaves, well my Lancia Fulvia has a transverse leaf spring at the front (common practice on early 1950's F1 cars) and has independent front suspension via long unequal length double wishbones. It works very well (it has 1 degree negative camber) as the Fulvia's numerous rally successes confirm (sadly not with me driving )

VAR1016

Positive camber was used on pre war cars because the tyres were so inadequate for the power being supplied to them that the understeer moment generated by the positive camber (camber thrust acting outwards in the turn) prevented the cars from spinning if the driver so much as brushed the throttle.

Ben

You may well be right on the fact that it was tyre construction - I'm not all that clued up on prewar stuff to be honest.

It seems a more than logical argumen which normally wins anything technical!;)

Originally posted by Fizzicist
You may well be right on the fact that it was tyre construction - I'm not all that clued up on prewar stuff to be honest.

It seems a more than logical argumen which normally wins anything technical!;)

Just something I heard. Ben's post explains it neatluy.

have a look at a Type 35 Bugatti - reckoned ot be one of the greatest-handling cars of the 1920s. This one ran a great deal of positive camber - about 3 - 4 degrees by the look of it I would say.

VAR1016

The beast I have in my mind was the Bentley Eight.

I tell ya, when I get married I want a pre-war Bentley as the wedding car! Either that or a Facel Vega FV or an Alvis TF21. But those Bentley's are scary:D

Originally posted by Fizzicist
The beast I have in my mind was the Bentley Eight.

I tell ya, when I get married I want a pre-war Bentley as the wedding car! Either that or a Facel Vega FV or an Alvis TF21. But those Bentley's are scary:D

Ah! you mean the Bentley 8-litre?

This was indeed a splendid monster - and as with (I think) all the six-cylinder W.O. Bentleys, featured the rather attractive 3-throw eccentric means of driving the overhead camshaft - Bentley wanted to make luxury cars and this method of driving an overhead cam was very silent - and derived from steam locomotives (Bentley did his apprenticeship at the Great Northern railway works at Doncaster). The 8-litre was receptive to development - Forrest Lycetts's car being one of the more famous examples; even in the 1950s it could manage over 140 MPH and 0-100 in about 20 seconds, very fair going for a vintage car. I have never been allowed to drive anyone's vintage Bentley, but I suspect it is probably fairly demanding!

I am familiar with the 3-litre Alvis however - I have had two TD21s. A pleasant touring car although rather prone to rust. Your choice (the TF) is the best. This one had improved rear springing, triple carburettors and a special camshaft; its rather old engine managed 150 BHP. With 0-60 in under 10 seconds and a top speed of about 125 MPH, it was a decent performer for its size and weight in 1966. I once saw a special experimental 3-litre that was owned by David Michie who was MD of Red Triangle the company that still supplies spare parts for all the Alvis models. This one was rumoured to have six Amal carbs and about 210 BHP. As a postscript to the 3-litre story, Rover bought Alvis in 1965 and was apparently intending to install the aluminium 3.5 litre V-8 into the TF. I think that would have been a lovely car.

Sorry! I have waffled for too long.

Best of luck

VAR1016 (Lancias these days)

You are clearly a man of good taste ;)

Originally posted by Fizzicist
You are clearly a man of good taste ;)

And you, sir, are very generous!

VAR1016

if you want to expire with camber go play gpl !

Originally posted by Fizzicist
Increased Negative Camber has a couple of effects:

1) The steering responds to changes faster, conversely the car is less directionally stable in a straight line.

2) As the suspension loads up and the car 'leans' in the corner, the camber effectively disappears and as the contact patch grows on the outside tyre, grip increases, eliminating understeer, as it's only of benefit on the front wheels.

Negative camber also increases straightline speed as there is less of the contact patch on the road down the straights, therefore, less drag (on the fronts).