Most of us have seen someone driving around with -30 degrees camber, and wondered what’s wrong with their car. If you haven’t, don’t worry, you aren’t missing much. Then, however, we look to competitive drift cars and see they run camber as well. Frankly nowhere near -30, closer to the -5 range in front, but why do they run any camber?
(Just an FYI, in case you didn’t already know, negative camber is the the top of the wheel tilted in. Positive is the wheel tilted out.)
Drift cars run camber in the front to increase their contact patch at steering lock. As they turn the wheel, their front tires gain positive camber, which is negated by the static negative camber. Thus, while steering, the lead wheel will be as close to flat as possible. The rear wheels of a drift car run zero camber, or even slight positive camber. Cars with lower power run closer to zero camber, since under acceleration, their rear suspension doesn’t squat as much. Formula Drift cars run a little positive camber, so when their suspension squats from 1000+ horsepower, the negative camber added is cancelled out by the static positive camber.
That’s a lot of information to swallow in one paragraph, even for me. Let’s break it down some more below!
Why Do Drifters Run Negative Front Camber?
The front wheels on a drift car are essential for two main things, flicking the car into a drift and for altering direction mid-corner. Flicking a car into a drift can be aided by horsepower and momentum, so you don’t need peak grip there. When you really need the grip is mid-drift, in order to keep your direction under control. That’s where your leading tire comes into play. If you’re in a left-hand turn, your right wheel will be the furthest forward, so that’s your lead tire. Vice versa is true for a right turn.
Why choose the lead tire? Why not the inside tire?
Once your rear wheels start to spin, you’re applying a torque trying to lift the front end of your car up. While you’re sliding, that’s putting a force trying to lift the trailing edge of your car up. Those forces culminate on your inside front tire, which can commonly be seen entirely in the air during a drift. If we ran positive camber to optimize for grip on that wheel, and it were to lift in the air.. You’d essentially have no front grip, and end up having a very intimate connection with the wall for a moment.
(Yes, this is a shot from Horizon 4, and a tune made to pop the wheel, but the point still stands. The net angle of propulsion is almost directly pointing at said wheel, which with soft suspension, lifts it.)
How do you maximize the contact patch of your lead tire?
Well, this is a mixture of your caster angle and your camber. Try to imagine a line that follows your shock tower, from the steering knuckle straight up to where the shock mounts under the hood, that’s your caster. If that line tilts towards the rear of the car, that’s positive caster (that’s good!). If it tilts forward, that’s negative caster (no bueno). Adjusting your caster angle influences how much your car self-steers while in a drift. Most people I’ve talked to have it maxed out positive, to get the most self-steer benefits.
Where does that play in to negative front camber though?
That caster adjustment changes the axis the wheel turns on when steering. If you had zero caster, your wheel would turn on the very bottom of the tire, and add no camber during the turn. However, you’d get no self-steer while drifting. With positive caster, however, you’re turning on a tilted axis, with the steering forces being applied more towards the rear of the tire. This is why caster controls self-steer as well, since the steering is behind the axis of turning. The forces exerted by the ground on the tire can now push back on the steering rack, which is the self-steer drifters seek.
When you’re turning on a pivoted axis, then the top of the wheel is also moved when turning. We’ll talk about the left front wheel for a second. If you’re turning left, then the top of the wheel is pushed outwards, adding positive camber, since the caster angle is behind the top of your tire. If you turn right, the top of the tire is pushed in, adding negative camber. Now, when you’re drifting around a right-hand corner (as seen in the photo), your wheels will be turned left to control the skid. Your front left tire will be the lead tire, and positive camber is added during the turn. Since we’re running static negative camber in the front, the addition of positive camber cancels that out. Thus, our lead tire is left with a flat contact patch, and the highest grip possible.
Why don’t more street cars run this much negative camber?
Running this much negative camber has severe downsides for straight-line driving. While drifting, sure, it’s extremely helpful to have this grip, but it leaves you with such a small contact patch while not drifting. The most severely negative effect is that your braking distance is severely reduced. Since you don’t have as much grip in the front end, and that’s where the majority of your braking is done, it takes much longer to stop.
(Fun fact, that’s why most drift cars don’t run big brake kits, instead opting for smaller, lighter brake systems. They can’t effectively use their brakes, since the limiting factor is their tires’ contact with the ground, so they opt for weight reduction instead.)
While in a normal corner, your grip is also severely reduced. If you had to swerve out of the way of something, you’d feel tons of understeer, since your tires can’t handle such a sudden turn. The setup in the rear of your car however, with nearly 0 camber, that will be perfectly safe for street driving. If you’re able to do your own alignment jobs, then you’d only need to adjust the front for street driving.
Why Do Drifters Run Zero (Or Slightly Positive) Camber In The Rear?
The goal of drifting isn’t to not have grip, but to have as much as you can use. With the thousands of horsepower on tap, these drift cars can use as much grip as they can get. What about at the grassroots level though? There’s only a few hundred horsepower in these engines, yet they still get big angle. Their suspension setup is much more rigid, with increased camber, to decrease the amount of traction at the rear wheels. This allows for the wheels to keep slipping, even significantly lower horsepower.
What about that high horsepower setup though? Putting that much power down is easy, but actually using that much power is difficult. Having large, sticky tires is always good, hence drag racers tubbing their rear ends for more tire room. In a sport that limits tire width, however, you need to rely more on suspension geometry to increase your mechanical grip. Soft springs, soft sway bars, and slight positive camber all attribute to having the highest grip possible, by adding what’s known as “mechanical grip”
What is “Mechanical Grip” And How Do They Get It?
Mechanical grip is when parts of your car that aren’t the tires assist in delivering power to the ground. With roll bars, they help the car maintain better side-to-side weight distribution, without wheels lifting off the ground. The soft springs allow the car to squat when power is applied, letting the suspension pre-load and absorb some of the power being applied. That positive camber, though, that’s what ties the setup together. See, since the springs were made soft enough for the rear to squat, but when most rear suspensions squat, they add negative camber. Thus, if the car had negative camber then were to squat, it would reduce the contact patch even further.
However, having static positive camber in your setup predicts the addition of negative camber, and compensates for it. Now, when the car squats under power, the negative camber that’s added is cancelled out by the positive static camber, leaving you with a flat contact patch while in motion. That power squat happens for almost all drift cars, but Formula D cars more so. Putting 1,000+HP to the rear wheels with soft rear springs will certainly squat the rear, flattening your contact patch, and giving you the most grip possible.
Should I Run Negative, Positive, or Zero Camber?
That is entirely up to your driving style! If you’re willing to sacrifice handling to have a presence, then you’re free to run lots of negative camber like the “stance” boys. Looking to tear up the streets in an aggressive grip setup? Just a little negative camber in front and zero rear camber will be your best bet. Are you trying to put down thousands of horsepower in a straight drift car? Negative in front and positive in rear will make up for that squat.
What Camber Should I Run On The Street?
Running an extremely aggressive camber profile on city streets is illegal in most states, as well as dangerous. It hinders your car’s ability to stop and turn in an emergency. However, running negative camber can be part of the styling for your car, and sometimes form comes before function. Numbers that aren’t unheard of for street use can range from -2.0° to +0.5°. It really does depend on what style you want your car to have, and how much handling you’re willing to sacrifice.