Is camber gain really beneficial?

[g-force_addict]

While negative camber provides thrust
Does it really improve cornering?
Some camber vs lateral force tables indicate negative camber actually DECREASE cornering force.
Maybe some slight negative camber (less than 1 degree) might actually improve cornering but just slightly and mainly by counteracting tire deflection.

I've read radial tires won't benefit much from negative camber unlike bias ply tires.

What gives?

[RH1300S]

AFIK 'Camber gain' is a situation where the action of turning the wheel creates additional camber change due to the wheel pivot around the steering axis (castor angle mainly affect this).

To answer your question, surely it is simply the case of keep adding negative camber until you stop going faster. The camber angle required depends on the car, the tyre and the track.

[Roland Ehnström]

If it didn't help they wouldn't be using it.

[Jersey Tom]

I've read radial tires won't benefit much from negative camber unlike bias ply tires.

What gives?

Not sure where you've heard these things. It can most definitely be an immense gain to cornering performance.

There's a reason why F1 teams run 3-4 degrees camber and NASCAR runs as much as double that. Both on "radial" tires.

[hardingfv32]

3-4 degrees camber and NASCAR runs as much as double that. Both on "radial" tires.

Do the inside NASCAR tires require a similar amount of positive camber or are the numbers different for some reason?

Brian

[Jersey Tom]

There are reasons.

And let's not forget that there's an advantage to going to even higher camber on the F1 tires - if they'd survive it. Red Bull showed that last year, no? With the whole camber limit and blistering thing.

[raymondu999]

For performance I suspect given the banking and the length of the cornering Nascar could probably still benefit from more camber, no, JT? Laptime wise that is. Obviously it would probably impact tyre life though.

[Pierce89]

It blows my mind every time I see the positive camber on a Nascar left front up close. Hey JT, without giving up trade secrets, whats the ballpark range for positive camber on the left fornt for a high banked 1.5 mile track? uhh say Atlanta or Texas. 8-12 degrees? All the way up to 15 maybe?

[you_nes]

So I'm new here (long time reader, first time writer) so please forgive me for jumping into your conversation unannounced...

BUT This topic is mixing a few things all together and I thought I would try and clarify.

Firstly, camber gain and static camber are not the same thing.
- Static camber is the angular misalignment of the tires centre line from a vertical plane when stationary. (unit = deg)
- Camber gain is the change in camber with changing geometry. (unit = deg/mm, deg/deg or deg/g depending on use)

I think we are talking mostly about static camber here as (at least to my eyeballs) f1 cars do not have much built in camber gain.

and second, camber gain is the change in camber with ANY change in geometry. For most front suspension designs (including F1) this means that there are 2 separate mechanisms for camber gain.
- Steering (castor + scrub effect) go-cart steering is a good example of this.
and
- Suspension displacement (wishbone geometry effect.)

As I said before f1 cars do not seem to have much camber gain from either mechanism. On the other hand, I remember seeing some old photos of a NASCAR lower wishbone which was very short, if this is still the case it's likely that they have HUGE camber gain from suspension displacement which is probably why they have such large static camber to compensate (so the tire ends up with some, much smaller, positive camber at race speed when the front lip has sucked the car down to the road.)

And for what its worth I did some research a few years back into tyre "camber tolerance" and raymondu999 is right on the money when he says that heat is the limiting factor in choosing appropriate camber settings. too much on a stiff tire and you overheat the inside edge, too little on a soft one and you cook the outside. The whole radial/bias ply comparison is pretty useless these days though because the tire companies are pretty good at blurring the line between the 2 and most Motorsport tires end up not really being either one or the other. (they angle, or bias, the radial plies so I suppose you could call them biased radials or radial biased?)

so yeah, keep adding camber until you blister the inside edge of your tire and then back it off a bit! (pretty much what redbull and co learned at spa last year!)

[raymondu999]

Welcome aboad you nes. Do you mean stiff suspension or stiff sidewalls when talking of heat and camber?

[Roland Ehnström]

It blows my mind every time I see the positive camber on a Nascar left front up close. Hey JT, without giving up trade secrets, whats the ballpark range for positive camber on the left fornt for a high banked 1.5 mile track? uhh say Atlanta or Texas. 8-12 degrees? All the way up to 15 maybe?

As far as I know NASCAR runs about -4 static camber on the RF and +7 or so on the LF. RR -2, LR +2, give or take. These are just ballpark figures of course.

[raymondu999]

Wow that's quite a lot of difference between the left and right.

[you_nes]

Do you mean stiff suspension or stiff sidewalls when talking of heat and camber?

As with anything, its not ever just one thing but in this case its mostly tires!
sidewall stiffness, aspect ratio, pressure and normal force (and others) all contribute.

[Jersey Tom]

By rule in Sprint Cup you can "only" run +8 degrees static LF camber. I believe in Nationwide it is +9. With 4" of travel to get the front end down, depending on your geometry that can obviously change. If you watch footage of a race at Martinsville (coming up in a couple weeks) you'll see a lot of cars with very high rate camber curves on the LF and a huge amount of camber change through the corner.

Sometimes though you do indeed hold a lot of camber through the corners. A lot. Though I'm not going to disclose specific numbers.

Why so much? Because you can get away with it. Not to be too biased, but credit to Goodyear for having extremely durable tires. The duty cycle of both load and speed for NASCAR right side tires at the high load tracks (Texas, Charlotte, etc) is probably double what a F1 tire would see - your minimum speed is 150 mph / 240 kph and since you always turn one direction the tires never get a chance to really unload. The huge banking angles create immense amounts of vertical load, even if the aero downforce isn't as high.

[g-force_addict]

I've read radial tires won't benefit much from negative camber unlike bias ply tires.

What gives?

Not sure where you've heard these things.

Bias-ply tires have been found to generate more camber thrust than radial tires

http://en.wikipedia.org/wiki/Camber_thrust

There's a reason why F1 teams run 3-4 degrees camber and NASCAR runs as much as double that. Both on "radial" tires.

You said it right.
"Radial" tires
Racing tires aren't really radial tires.
They are "slightly bias ply" tires as their reinforcing belts aren't exactly perpendicular like true radial tires. They are actually angled thus they are really bias ply tires.

So I'm new here (long time reader, first time writer) so please forgive me for jumping into your conversation unannounced...

BUT This topic is mixing a few things all together and I thought I would try and clarify.

Firstly, camber gain and static camber are not the same thing.
- Static camber is the angular misalignment of the tires centre line from a vertical plane when stationary. (unit = deg)
- Camber gain is the change in camber with changing geometry. (unit = deg/mm, deg/deg or deg/g depending on use)

I think we are talking mostly about static camber here as (at least to my eyeballs) f1 cars do not have much built in camber gain.

and second, camber gain is the change in camber with ANY change in geometry. For most front suspension designs (including F1) this means that there are 2 separate mechanisms for camber gain.
- Steering (castor + scrub effect) go-cart steering is a good example of this.
and
- Suspension displacement (wishbone geometry effect.)

As I said before f1 cars do not seem to have much camber gain from either mechanism. On the other hand, I remember seeing some old photos of a NASCAR lower wishbone which was very short, if this is still the case it's likely that they have HUGE camber gain from suspension displacement which is probably why they have such large static camber to compensate (so the tire ends up with some, much smaller, positive camber at race speed when the front lip has sucked the car down to the road.)

And for what its worth I did some research a few years back into tyre "camber tolerance" and raymondu999 is right on the money when he says that heat is the limiting factor in choosing appropriate camber settings. too much on a stiff tire and you overheat the inside edge, too little on a soft one and you cook the outside. The whole radial/bias ply comparison is pretty useless these days though because the tire companies are pretty good at blurring the line between the 2 and most Motorsport tires end up not really being either one or the other. (they angle, or bias, the radial plies so I suppose you could call them biased radials or radial biased?)

so yeah, keep adding camber until you blister the inside edge of your tire and then back it off a bit! (pretty much what redbull and co learned at spa last year!)

That's right.
Negative static camber helps keep the tire RELATIVELY vertical during body roll.
And yes during body roll F1s run very little or even no net negative camber, specially for the inner wheel.