Question About Negative Camber: More Negative Camber == More Grip at Corner?

[Figo]

Hey guys.

Iv seem some people run -2.5 or even -3 camber.

Im confused that does "More Negative Camber == More Grip at Corner" correct?
"=="means "Always Equal to".

Iv read <How to Make your Car Handle> by Fred Puhn, and I remember that in the book he said more negative camber does not always equal to more grip. Factors like Speed and G-force affect the change of camber alot.

For example, I am thinking that -2 camber may not be as gripy as -1 camber at the corner when speed is only 30mph, and might be more gripy when at 50mph?

So If i would like to build a car that can easily slide at low speed like 20mph, but grip at high speed like 50mph, I should run more negative camber at rear right? May be -1.5 front and -2 rear instead of -2 front and -1.5 rear.


But it does not make sense that some drift car run -3 front but -1 rear.

[7thgear]

i'll write something intelligent later

but for now,

[Figo]

Originally Posted by 7thgear

i'll write something intelligent later

but for now,

Iv seem a lot of people said:"more negative camber front and less negative camber rear make you car oversteer."

So Im confused. I dont think more negative == more grip. And doubt that -3 front and-1 rear can make a low speed drift car.

There might be a range..

[Zach3794]

I don't really wanna get too into it...but "reducing understeer" is not always the same as "increasing oversteer". The front of these cars utilize a macpherson suspension, and as such, their camber curve sucks. They actually tend to gain positive camber under compression. That's why the front needs a lot more negative camber than the rear. The rear, being a multilink design, gains negative camber rather easily, and should have less than the front.

I know a lot of people on this forum say this car oversteers like crazy, and I thought that way for awhile too, but really that's the driver. In reality, once I improved my driving, I found that at the limit the car had a strong tendency to understeer. Smoother input and throttle control will really help you make leaps and bounds in controlling the car.

As far as alignment, camber is just the tip of the iceberg, and I'm sure more knowledgeable folks will chime in here soon enough

[7thgear]

GRIP is the end result of a number ofthings



The tire



It’s contact patch



Force acting on itvertically (more vertical load = more grip, this is vehicle weight and aero)



Force acting on itlaterally ( weight transfer during cornering, once you exceed the tire’sability to grip the surface laterally, you start to slide)



Force acting on ittorsionally (power delivery, too much power and you start to spin)





You have a wholebunch of things at your disposal to control and modifyi these parameters…



Adjust camber isjust one of them.



So it’s not that Xfront camber and Y camber will give me grip, and if I deviate from thatmagically start to slide. It’s simple one of many adjustments you could do.



A car going straightwill always grip so long as the road surface doesn’t change and that the forceacting down on the car is higher than lift.



A car going turningwill grip until it doesn’t. You can adjust that.



So knowing all this,can you make the right conclusions?

[Figo]

So I kinda get it. macpherson earn camber at the corner easier than multilink....Is that wat u mean?

For example, someone set the car to front -2, rear-1.5. At a corner the camber of outter wheels might change to around -1 and -0.8.

I actually like oversteer car. Lots of fun. And thats the reason why I bought an FR-S.

Originally Posted by Zach3794

I don't really wanna get too into it...but "reducing understeer" is not always the same as "increasing oversteer". The front of these cars utilize a macpherson suspension, and as such, their camber curve sucks. They actually tend to gain positive camber under compression. That's why the front needs a lot more negative camber than the rear. The rear, being a multilink design, gains negative camber rather easily, and should have less than the front.

I know a lot of people on this forum say this car oversteers like crazy, and I thought that way for awhile too, but really that's the driver. In reality, once I improved my driving, I found that at the limit the car had a strong tendency to understeer. Smoother input and throttle control will really help you make leaps and bounds in controlling the car.

As far as alignment, camber is just the tip of the iceberg, and I'm sure more knowledgeable folks will chime in here soon enough

[Draco-REX]

Super simple explaination:
Tires grip the road.

Tires grip best when they are vertical (0 camber)

When you turn your car, it leans to the outside which tilts the tire away from vertical (positive camber).

If you lean the tire inwards (negative camber) when going straight, it'll be closer to vertical when the body leans (positve camber cancels out the negative camber, i.e. -1 + 1 = 0)

The trick is figuring out how much negative camber you need to offset body roll and other sources of camber change. That's where all the complexity comes in.

[Figo]

Thank you. lol.
I knew there r many factor. I might try the camber first.

I think @Zach3794 is correct. Its all about camber curve.

If the front and rear have the same camber curve, I dont think for the front -2 rear -1 setting, the front will earn more grip before the rear go to positive.

Originally Posted by 7thgear

GRIP is the end result of a number ofthings



The tire



It’s contact patch



Force acting on itvertically (more vertical load = more grip, this is vehicle weight and aero)



Force acting on itlaterally ( weight transfer during cornering, once you exceed the tire’sability to grip the surface laterally, you start to slide)



Force acting on ittorsionally (power delivery, too much power and you start to spin)





You have a wholebunch of things at your disposal to control and modifyi these parameters…



Adjust camber isjust one of them.



So it’s not that Xfront camber and Y camber will give me grip, and if I deviate from thatmagically start to slide. It’s simple one of many adjustments you could do.



A car going straightwill always grip so long as the road surface doesn’t change and that the forceacting down on the car is higher than lift.



A car going turningwill grip until it doesn’t. You can adjust that.



So knowing all this,can you make the right conclusions?

[Zach3794]

If you read racecompengineering's sticky in this forum, it'll go into motion ratios and that explains why the macpherson's have a different camber curve than the multilink setup.

I think what you mean is that you like the rear end of the car to come out. As I said before the FR-S and BRZ both naturally understeer, but with driver input, yes, you can get the back to come out rather easily. The point is that engineering understeer into the car will make recovering from that slide much easier than a car whose design is to simply keep letting the back out at the limit.

[Draco-REX]

BTW, How to make your car handle, and Tune to Win by Carroll Smith are both excellent reads, if a little dated (ignore the aerodynamics chapters). They both cover roughly the same material, but with two different perspectives. I found reading both gave me an even better understanding than if I had just read one.

[Zach3794]

The front and rear do NOT share the same camber curves; they're completely different suspension types.

Like Draco said, the whole point, regardless of your intentions with the car, is the maximize the contact patch of the tire in the corner with your camber adjustment. It is naturally different between front and rear, and different between drivers even because of their tendencies.

The point is that the general rule of thumb on this car is that more negative camber in the front will give you large improvements in cornering grip. Remember, even drift cars have extreme levels of grip, they would never be able to recover otherwise.

[Figo]

I knew wat u said.

But say if we set -2 front and -1 rear camber. At low speed, the camber might changed to -1.5 and -0.8, the rear wheels still have more grip.

Actually, the rear wheel will always got more grip until they go to positive camber.

so for a more negative front camber drift car, they always suppose to make rear camber go to positive at every corner?

Originally Posted by Draco-REX

Super simple explaination:
Tires grip the road.

Tires grip best when they are vertical (0 camber)

When you turn your car, it leans to the outside which tilts the tire away from vertical (positive camber).

If you lean the tire inwards (negative camber) when going straight, it'll be closer to vertical when the body leans (positve camber cancels out the negative camber, i.e. -1 + 1 = 0)

The trick is figuring out how much negative camber you need to offset body roll and other sources of camber change. That's where all the complexity comes in.

[7thgear]

Originally Posted by Figo

Thank you. lol.
I knew there r many factor. I might try the camber first.

I think @Zach3794 is correct. Its all about camber curve.

If the front and rear have the same camber curve, I dont think for the front -2 rear -1 setting, the front will earn more grip before the rear go to positive.

no

camber and camber control helps maximize the contact patch of the tire. However it's effect is very limited in normal applications.

what determines of whether you grip or not is WEIGHT transfer. This is dictated by the springs, car weight/dimensions and driver input.

camber is just a small part, and it most definitely doesn't correlate to grip in the linear fashion that you are thinkging about.

it's not like the front has more grip because it is -1.0 camber vs -0.5 in the rear. NOT AT ALL.

[Figo]

I c, thank you, hah.

Originally Posted by Zach3794

If you read racecompengineering's sticky in this forum, it'll go into motion ratios and that explains why the macpherson's have a different camber curve than the multilink setup.

I think what you mean is that you like the rear end of the car to come out. As I said before the FR-S and BRZ both naturally understeer, but with driver input, yes, you can get the back to come out rather easily. The point is that engineering understeer into the car will make recovering from that slide much easier than a car whose design is to simply keep letting the back out at the limit.