Corner balancing explained
What corner weights and cross-weight (wedge) mean, why 50% cross makes a car handle the same both ways, and how corner balancing actually works.
Put a car on four scales and you'll almost never see the weight spread the way you'd guess. Corner balancing is the art of adjusting how that weight sits — not to make it "even", but to make the car behave identically in left and right corners.
The number that matters: cross-weight
Cross-weight (or wedge) is one diagonal pair's share of the total:
cross-weight % = (RF + LR) ÷ total weight × 100
At 50% the diagonals carry equal load and the chassis responds symmetrically. Above 50% the car gains grip in left-handers and loses it in right-handers; below 50%, the opposite. Oval racers run deliberate wedge because they only turn one way — a road or circuit car wants 50.0%.
Why you can't fix it with ballast alone
Front/rear and left/right distribution are set by where the mass physically is — engine, driver, tank. Cross-weight is different: you can change it without moving any mass, just by adjusting spring perch heights. Raise one corner and you jack extra load into it and its diagonal partner, taking it from the other diagonal. That's why it's also called "putting wedge in".
How a corner-balance session actually goes
- Set ride heights first — corner balancing is done at your final ride height, alignment roughed in.
- Load the car as it runs — driver weight (or ballast) in the seat, fuel at your normal level. This changes the numbers a lot.
- Scale it on a flat, level pad — even a few mm of floor slope corrupts the reading.
- Adjust perches diagonally — a small turn on one collar moves cross-weight a few tenths of a percent; re-scale after each change.
- Re-check alignment — perch changes move ride height slightly, which moves toe and camber.
What it fixes (and what it doesn't)
A balanced car turns in consistently both directions, puts power down evenly out of corners and brakes straight. What corner balancing can't do is overcome a fundamentally lopsided static distribution — it redistributes diagonal load, it doesn't move the engine. For that you're into relocating mass: battery to the boot, lighter seats, and so on.
FAQ
What should my cross-weight be?
For road and circuit driving: as close to 50.0% as you can get, measured with the driver aboard. Only deliberately offset it (wedge) if you race ovals or a track that turns predominantly one way.
Do I really need to sit in the car?
Yes — 75–100 kg placed off-centre changes corner loads by several percent, easily more than the imbalance you're trying to fix. Use the driver or equivalent ballast in the seat every time.
Can I corner balance without adjustable coilovers?
Not meaningfully. Cross-weight is adjusted through spring perch height, so you need height-adjustable spring platforms on at least one axle. Without them, focus on mass placement instead.