Alignment Part 1

We see it all the time. Someone spends $2,500 on coilovers, $4,000 on wheels and tires, plus another $500 on swaybars…then gets an alignment to set the car back to factory specs.

Don’t do that.

A performance alignment can make a big difference, even if you don’t have any other vehicle modifications. But what exactly is a “performance” alignment? How is it different?

First, we’ve got to go through the basics.

Like the rest of the car, the factory specifications are a compromise. These specs are usually given as a range, and sometimes a fairly large one. All of the parameters are conservative, which means minimal tire wear and fewer problems if the alignment isn’t perfectly even. Good enough to get out the door.

The other objective is predictable handling for the average driver, even for sports cars. The goal is to feel “tight”, responsive, and safe…even when driven poorly. You can expect plenty of understeer on corner entry.

That’s affected by both the alignment and suspension design. That factory alignment is designed for the factory suspension and tires.

So what’s a “performance” alignment?

If you have different goals, or you’ve made big changes to your car, the factory specs don’t mean much. Spring rate, ride height, and tire changes alter how the car rolls onto the tire, requiring different settings to maximize grip. A good suspension tuner can help and testing can be done to dial it all in.

Camber is usually the big question. This defines how the top of the wheel is tilted inwards or outwards towards the center of the car. It’s measured in degrees.

When cornering, the tire deforms and the wheel geometry can change as the suspension compresses.

Negative camber can improve grip by ensuring the car rolls onto a flatter contact patch, rather than rolling onto the outer edge of the tire.

If someone is trying to push you over, you brace yourself with your back leg. If you stand straight upright or lean back, you’re going to get knocked down.

Few cars have more than -1° of camber from the factory. A focused autocross car may have up to -5° in front.

Too much camber can reduce braking performance and does increase tire wear. But even a small increase in negative camber can make a big change in handling with only a small effect on tire wear (or an improvement).

Toe describes how the wheels are pointed inwards or outwards from the centerline of the vehicle. This is measured in degrees, millimeters, or inches. When measured in millimeters or inches, it is dependent on the tire size used.

Toe in is the case where the front of the tire is closer to the centerline of the car than the rear of the tire. Toe out describes the opposite case.

Lots of toe in or out are uncommon on both street and track cars. A little bit of toe in at the rear of a car will improve stability. Driver preference plays a role with toe, but lots of toe will destroy tires and usually means something is wrong with the rest of the car.

We’ve got a lot more to talk about… including caster, bump steer, and how bushings can affect alignment set up. The first step is figuring out what you can use to make changes, since your car might not have much adjustment stock. We’ll talk more about that next time.