Driving inputs
Trail braking
Carrying brake pressure past turn-in and bleeding it off progressively as you add steering, so the nose stays loaded and the car rotates. Release too early and the front lifts and washes (understeer); too hard and the rear gets light.
Threshold braking
Braking right at the grip limit — a hard initial hit, then modulation just below lock-up — for maximum deceleration. On an ABS car it is the point where ABS only just intervenes.
Release rate
How fast you come off the brake. A clean dégressive release keeps the front planted into the apex; a sudden release unloads it and the car stops rotating.
Coast
Time spent neither on the brake nor the throttle — dead time at the apex. A little is normal; a lot means you brake too early or hesitate to get back to power.
Slip angle
The angle between where the tyre points and where it actually travels. A few degrees builds grip; too much scrubs the tyre and wastes speed.
Consistency
How repeatable your laps and corner inputs are. The number-one separator of pace — you cannot tune a car you cannot reproduce.
Apex min/max speed
Your minimum (apex) speed in a corner, tracked across laps. A wide min-speed spread at the same corner is lost time hiding in execution, not in the car.
Tyres & grip
Grip fraction (grip utilization)
How much of a tyre's grip is in use, 0-1, from the friction circle: √(lateral² + longitudinal²) ÷ (µ × vertical load). Front vs rear is the tyre-level read of understeer/oversteer; including the longitudinal part also catches wheelspin on exit.
Temperature window
The carcass temp band where the compound grips. Cold = no grip and the tyre slides; over the top = greasy. Read the inner/middle/outer spread for camber and pressure.
Pressure rise (cold → hot)
How much pressure builds from the cold set value to running. Too little rise = cold pressure too high (tyre under-worked, bulges at the centre); too much = cold too low (tyre over-worked).
Wear per lap · cliff · tyre life
How fast each tyre wears (%/lap), the projected lap where grip falls off a cliff, and the estimated laps of life left. The worst corner usually names the limiting tyre.
3-zone temps (I / M / O)
Inner, middle and outer tread temperatures. Inner hot = too much negative camber; outer hot = too little; middle hot = over-pressure; both edges hot = under-pressure.
Aero & load
Center of pressure (CoP) & migration
The front/rear split of aero downforce, in percent — e.g. CoP front 37% means 37% of the aero load is on the front axle. Migration is how it shifts with speed: + = the front gains load at speed (more front bite in fast corners), − = the rear loads up. On LMU downforce is not exposed, so it is estimated from ride-height change vs speed and the spring rates.
Center of gravity (CoG) / load transfer
Where the mass effectively sits, read from the vertical load on each tyre. Front/rear (e.g. 46% front at speed) and left/right tell you which corner carries most. On a track with a dominant turn direction the loaded side can carry 30%+ more — the root of uneven wear and heat, and a case for an asymmetric setup.
Max lateral G
Peak cornering grip the car actually pulls. A reference for how much the platform and tyres are giving in the corner.
Brakes
Brake thermal window (onset / peak / median)
The temperature band where the brake material works. Below it the discs are glazed and braking is lazy; above it they fade. Coupled with deceleration and tyre warm-up through the duct setting.
Brake bias
The front/rear split of braking force — the first number is the front (54.5 = 54.5% front). Too far forward and the front washes under trail braking; too far back and the rear gets unstable on entry.
Brake migration
An automatic shift of brake bias toward the rear as you release the pedal, to help rotation on corner entry without making the initial hit unstable.
ABS frames/lap
How many telemetry frames per lap the ABS is modulating — the amount of ABS intervention, not a count of discrete triggers. A high value (plus a high ABS % of braking frames) means you lean on the ABS instead of braking at the threshold.
Suspension
Shock velocity peak (F/R, bump/rebound)
How fast the damper shaft moves. Slow shaft speed = body control (roll, dive, squat) → set with slow bump/rebound; fast shaft speed = kerbs and bumps → set with fast bump/rebound.
Roll & pitch rate
How fast the body rolls in corners and pitches under braking/acceleration. High roll points to ARB/spring; high pitch under braking points to slow front bump.
Bottoming (talonnage)
The floor hitting the ground when the suspension runs out of travel — a sudden loss of downforce and a light, vague steering feel. Under braking it is the nose diving too fast, which is a damper problem (slow bump), not just a spring/ride-height one.
Engine & cooling
Grille / radiator blanking
Tape or panels that block part of the airflow to the radiators. Closing the grille cuts drag and adds downforce but lets the engine run hotter; opening it cools the engine at an aero cost. It is the aero-vs-cooling lever of the power unit.
Oil temperature
Engine oil temperature. Too cold and the oil is thick and the engine is down on power; too hot and it thins and the engine is at risk. Read it against the grille setting.
Water / coolant temperature
Engine coolant temperature — the primary cooling readout. Sustained high values mean the cooling is insufficient. On some sims (iRacing, Automobilista 2, Assetto Corsa) leaving the engine running while stopped removes the airflow and temps climb fast enough to damage the engine.
Engine map
A selectable mode that trades power against fuel/energy use, response and heat. A leaner map saves fuel and runs cooler; an aggressive map makes more power but burns and heats more.
Strategy
Fuel/lap · laps remaining · limiting factor
Real fuel burned per lap (start minus end), the laps of range left, and which of fuel, energy or tyres runs out first — the limiting factor that decides stint length.
Virtual energy (VE)
On energy-coupled cars a budget that depletes alongside fuel and can be the real stint limit. Shown as a % with a per-lap consumption.
Lift & coast
Lifting before the braking point to save fuel/energy, trading lap time for range. Each level (L1-L3) has a saving and a time cost.
Race-format scenarios
For a given car, projecting the number of stops and stint length across race lengths (20 min → 24 h) from your measured pace, consumption and tyre life — so you can plan a format before you run it.
Micro-sectors / ideal lap
The track in ~24 mini-sectors; the best of each, summed, is your true ideal lap — sharper than the classic three-sector theoretical best.