Alignment is the cheapest performance change you can make and the easiest one to get wrong. It changes how the car turns more than most bolt-on parts do, and it is the one adjustment where a bad decision has a genuine safety cost rather than just a disappointing one.
This article covers what each setting does and what it trades away. It does not give you numbers. There is a reason for that, and it is explained below.
What does camber actually do?
Camber is the tilt of the wheel viewed from the front of the car. Negative camber leans the top of the tire inward, toward the car.
It exists because a tire does not stay flat to the road while cornering. Body roll and the flex of the tire's own sidewall roll the contact patch onto its outside shoulder, and a tire riding on its shoulder is using a fraction of its width. Static negative camber pre-tilts the wheel so that when the car rolls and the tire deflects, the contact patch arrives roughly flat on the road at the moment it is being asked to do the most work.
More negative camber therefore increases grip in sustained cornering. It does this by giving up straight-line contact patch, which is where every trade-off below comes from.
Will more negative camber wear my tires out?
On a street car, yes — on the inner edge, and the wear is not always obvious until the inner shoulder is finished while the rest of the tread still looks healthy. Check the inside edge by hand, not by eye.
How fast depends on how much camber, how much of your driving is straight-line commuting, and the tire itself. A car that lives on the motorway spends nearly all of its tire life on a contact patch that camber is deliberately tilting off the road. A car driven hard at weekends recovers some of that cost in grip it actually uses.
The honest summary: a track-oriented camber setting on a car that mostly commutes is an expensive way to buy grip you rarely reach.
What does toe do, and why is it the setting to be careful with?
Toe is whether the wheels on an axle point slightly toward each other (toe-in) or slightly away (toe-out), viewed from above. Unlike camber, small toe changes produce large behavioural changes, and toe is also the largest contributor to straight-line tire scrub.
At the front, toe-out sharpens turn-in — the inside wheel is already pointed into the corner as you begin to steer. The costs are a car that follows road cambers and ruts more, feels busier at speed, and scrubs tread away in a straight line.
At the rear, toe-in adds stability. It gives the rear axle a self-centring tendency that resists the car stepping out. Reducing rear toe-in frees the car up and makes it rotate more readily.
Why the rear of a 911 is not treated like the front
On a car carrying roughly 60% of its mass behind the rear axle, rear toe is the setting with the most consequence and the least margin. The rear axle is already managing the majority of the car's weight and a large polar moment — a lot of mass, a long way back, that resists starting to rotate and then resists stopping.
Rear toe is one of the main things standing between that layout and a slide that arrives faster than you can respond to it. Reducing it makes the car more willing to rotate, which is sometimes what an experienced driver wants on a circuit, and is the last thing you want on a cold road with a mid-corner bump.
This is the single strongest reason this article does not print figures. A rear toe number copied from a forum post, applied to a car with different tires, a different ride height and a different driver, is not a setup — it is a guess with a real consequence. Rear alignment on a rear-engine car belongs to a shop that can see the car.
What does caster do?
Caster is the forward or rearward tilt of the steering axis. More positive caster increases straight-line stability, increases steering weight, and adds negative camber to the outside wheel as you steer into a corner — which is useful, because it is camber that appears when you need it and disappears when you do not.
The cost is heavier steering and more effort at parking speeds. Caster is also less freely adjustable than camber and toe on many cars, so in practice it tends to be set once rather than tuned.
Why do track and street want different settings?
A circuit is a known surface, driven warm, in one direction, at speeds where loads are high and repeatable. A road is cold, unknown, cambered, bumpy and shared with other people.
A track alignment optimises for sustained cornering load and accepts tire wear, tramlining and reduced straight-line stability as the price. A street alignment optimises for predictability, tire life and low-effort stability, and accepts that the last few percent of cornering grip is unavailable.
Neither is more correct. What is wrong is running a track alignment on a car that lives on the road and then being surprised by the tire bill and the way it chases ruts — or, worse, assuming that because a setup worked at a track day it is appropriate for a cold road with oncoming traffic.
What is corner balancing, and do I need it?
Corner balancing is the process of adjusting ride height at each corner so the diagonal weights of the car are as even as possible, with the driver's weight in the seat. An unbalanced car turns better one way than the other.
It requires ride height adjustability at each corner, which means coilovers. A fixed-height spring set like a PRO-KIT does not offer per-corner adjustment, so corner balancing is not part of that conversation. What you can and should do on any car is set the alignment properly once the springs have settled.
Do I need an alignment after fitting lowering springs?
Yes, always, without exception. Changing ride height moves the suspension through its geometry, and camber and toe both change as a result. A car that is lowered and not aligned is running settings nobody chose.
Let the springs settle first. A few hundred miles of normal driving lets everything take its final position, and aligning before that means aligning to a ride height the car is about to leave.
Budget for the alignment as part of the cost of the springs. It is not optional and it is not a detail.
Where should the numbers come from?
From a shop, working with your car. Specifically: your tires, your actual measured ride height, your wheel and tire sizes, and an honest answer about what proportion of the car's life is road and what proportion is track.
Good alignment shops have a starting point for these cars and will adapt it. Tell them what you want the car to do rather than handing them a number from a forum, and ask them to record what they set, so that next time you have a baseline to move from rather than starting over.
Bring the car with the tire pressures and fuel load you normally run, and sit in it if they are set up to align with driver weight.
Common questions
Is a track alignment safe on a street car?
Some of it transfers and some of it does not. Additional negative camber is largely a tire-wear cost. Aggressive front toe-out makes a car tiring and rut-prone on the road. Reduced rear toe-in is where street and track genuinely diverge on a rear-engine car, and it is the setting to leave conservative unless the car is a dedicated track car.
How often should I have the alignment checked?
After any suspension work, after any ride-height change, after a significant kerb or pothole strike, and whenever tire wear looks uneven. Cars that see regular track use benefit from more frequent checks, because kerbs move things.
Will an alignment fix my car pulling to one side?
Sometimes. A pull can be alignment, but it can also be tire construction, uneven pressures, a dragging brake or road camber. A shop should rule out the mechanical causes before adjusting settings to compensate for them.
Do sway bars change my alignment?
No. Bars do not alter static camber, toe or ride height, so fitting bars alone does not require a realignment — though it is a sensible moment to have the existing alignment checked, since balance tuning on top of a bad alignment is wasted effort.
Can I align the car myself?
You can measure toe at home well enough to catch a problem, and plenty of people do. Setting camber, caster and cross-weights to a repeatable standard needs proper equipment and a level surface. Given what rear toe does on these cars, this is not the place to save money.
An alignment is required after any change in ride height. Every suspension part in the catalog lists its full manufacturer application data on the product page.