Corner Balancing a 944 Before Time Trials

Corner balancing measures how much of a car's weight sits on each of its four wheels, not just the front-to-back and side-to-side totals a bathroom scale under each tyre would suggest. A 944 that looks level can still carry more weight on one front corner than the other, and that imbalance shows up as a car that turns better one way than the other, or that unloads a rear wheel earlier than it should under braking. The fix is a set of four corner scales, a known fuel level, and patience, done before alignment, not after.

What does corner balancing actually measure?

A corner weight scale sits under each wheel and reads the load that corner carries with the car at rest. Add the four numbers and you get total weight. Compare front to rear and left to right and you get the familiar distribution percentages. Cross weight is the diagonal figure: the left-front and right-rear loads added together, as a percentage of the total. Most road-course setups aim for a cross weight close to 50 percent. A car with a diagonal imbalance, more weight on left-front and right-rear or the opposite pair, turns differently depending on which way the corner goes.

This is not the same measurement as ride height. Ride height tells you how far the body sits from the ground at each corner. Corner weight tells you how much force that corner is carrying. Two cars can share identical ride heights and still have very different corner weights, because weight distribution depends on spring preload and chassis twist as much as on how high the car sits.

Why does ride height come first?

Changing a spring's preload to fix a corner weight also changes that corner's ride height, and changing ride height to fix a stance also changes corner weight. The two move together, so the order of operations matters. Set ride height first, to the target the suspension was designed around, then fine-tune corner weights with small preload adjustments. Chasing corner weight before ride height means redoing the ride height afterward, and chasing it the other way around wastes the same adjustment twice.

The PCA's technical Q&A on spring perch adjustment on a 944 follows the same order: tyre pressures set first, then ride height set to the figures in the factory manual, before anything finer is attempted.

What should the car carry on the scales?

A corner weight reading only means something if it reflects how the car will actually run. That means a driver's weight in the seat, or an equivalent ballast placed where the driver sits, a known and consistent fuel level, and every fluid topped to its working mark. A car weighed empty with no driver tells you nothing about how it will balance at speed with a person and a half-tank of fuel on board.

Tyre pressures matter here too, and they should be set to the pressure the car will actually run on track, cold, before the car goes on the scales. A pressure difference between corners changes the effective spring rate at that corner by a small amount, enough to shift a reading that is otherwise close.

How do you read an unbalanced result?

A car with excess weight on one front corner tends to understeer into a corner on one side and feel sharper on the other. A car with excess weight on a rear corner can show the opposite pattern, with the rear stepping out earlier on one side under trail braking. Neither symptom alone proves a corner weight problem, since tyre condition, alignment, and a worn bushing can produce similar feelings, but a lopsided scale reading combined with a one-sided handling complaint is a strong match worth checking before anything else is changed.

The fix is a small turn of preload at the light corner, scales rechecked, and another small turn if needed. Large adjustments in one pass usually overcorrect. Note each change, in perch turns or millimetres, so it can be undone if the numbers move the wrong way.

What does a scale pad session actually look like?

Four pads go down on a flat, level surface, ideally a shop floor checked with a level rather than assumed flat. The car rolls onto the pads under its own power and is left to settle for a few minutes, since a chassis that was just jacked up can read slightly different weights until it relaxes onto its springs. The driver, or an equivalent weight, sits in the seat. Fuel is at the planned track level. Tyres are at cold track pressure. Only then are the four numbers recorded.

From there the adjustment is iterative: turn a perch, roll the car off and back onto the pads to let it settle again, read the new numbers, and repeat until the cross weight sits close to the target and the ride heights are still where they should be. Rushing this step by skipping the settle time between adjustments is the most common reason a corner balance session produces numbers that do not match what the car does on track the next weekend.

Is corner balancing worth doing before every event?

Not every session needs a fresh scale pass. A car with unchanged springs, ride height, fuel habits, and driver weight should hold its balance from one event to the next, and checking the four corners with a tape measure for ride height drift is usually enough to confirm nothing has shifted. A full corner balance is worth repeating after any suspension work that touches spring perches or ride height, after a driver change, or when a car that handled evenly starts favouring one direction for no obvious reason. Treat it the way a shop treats torque specs: not a ritual to repeat on schedule, but a check that earns its place whenever something in the chain has actually changed.