Tuning Guides
The maths behind the mods, in plain English. Each guide explains one topic properly — then hands you the free calculator to run your own numbers. No fluff, no sign-up.
// Fitment & wheels
Tyre sizing, offset, PCD and the measurements that decide whether a wheel belongs on the car.
How to read a tire size
What every number on your tire sidewall means — width, aspect ratio, construction, wheel diameter, load index and speed rating — with worked examples.
6 minWheel offset explained
What ET / offset and backspacing mean, how positive vs negative offset changes where a wheel sits, and how to work out whether a wheel will clear or poke.
5 minBolt pattern (PCD) explained
What a bolt pattern like 5×114.3 means, how to measure yours with a ruler, the mm ↔ inch conversions, and why PCD is only part of wheel fitment.
// Engine building
Compression, cam timing, airflow, rotating speed and the numbers that shape an engine.
Compression ratio explained
What static compression ratio means, how it's calculated from bore, stroke, chamber and gasket, and what ratio suits NA versus boosted engines.
6 minCamshaft specs explained
How to read a cam card — duration, lift, LSA and overlap, what each does to the powerband and idle, and why overlap is a cam's personality number.
8 minEngine airflow & VE explained
How displacement, RPM and volumetric efficiency determine CFM, why mass airflow matters more under boost, and how to choose an honest VE.
7 minMean piston speed & RPM limits
How stroke and RPM set mean piston speed, why peak speed differs, and how to use the number as a durability comparison instead of a hard redline.
// Forced induction
Choose the compressor, understand pressure ratio and keep boost inside the combination's limits.
How to size a turbo
How to pick a turbocharger from a power target: required airflow in lb/min, pressure ratio, and how to read a compressor map without getting lost.
8 minBoost & effective compression explained
How boost becomes pressure ratio and a planning-only effective compression figure — and why temperature, fuel, timing and knock still set the limit.
// Fuel & tuning
Mixture strength, injector capacity and ethanol blends without unit traps or guesswork.
AFR and lambda explained
What air-fuel ratio and lambda mean, why stoichiometric differs by fuel, and the AFR targets tuners use for cruise, NA and boosted wide-open throttle.
6 minInjector sizing explained
How to size fuel injectors from a horsepower target: BSFC, duty cycle, cc/min vs lb/hr, and why oversized injectors hurt idle quality.
6 minE85 explained
What E85 is, why it makes more power and needs ~30% more fuel, what a flex-fuel conversion actually involves, and how to blend to a target ethanol content.
// Chassis & handling
Alignment, load transfer, corner weights and spring behaviour from the tyre contact patch upward.
Camber, toe & caster explained
The three alignment angles: what each one does, how each wears tires, and ballpark specs for street and track — plus the mm-to-degrees maths.
6 minBrake bias explained
What front-to-rear brake bias is, how weight transfer under braking sets the ideal split, and what happens when the balance is wrong.
6 minCorner 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.
8 minSpring rate & ride frequency explained
How spring rate becomes wheel rate through the motion ratio, how ride frequency compares setups fairly, and how to choose a useful starting point.
// Performance & drivetrain
Gearing, acceleration, drag-strip evidence, weather correction and the aerodynamic wall.
Power-to-weight ratio explained
Why power-to-weight predicts performance better than horsepower alone, how to calculate it in hp/ton and kg/hp, and how to compare cars fairly.
6 minGear ratios explained
What gear ratios and final-drive numbers really mean, how they trade acceleration against cruise rpm, and why tire diameter is part of your gearing.
6 minTrap speed vs ET explained
What quarter-mile ET and trap speed each measure, why trap speed is the honest power number, and how to read a drag strip time slip like a racer.
6 minDyno correction & density altitude explained
Why the same car makes different power on different days, how SAE J1349 correction factors work, and what density altitude tells you about NA power loss.
8 minTop speed: aero, power & gearing
Why aerodynamic power rises with the cube of speed, how to separate a gearing limit from a power limit, and why a calculated top speed differs from a real run.
// Diagnostics
Read what the car recorded before replacing anything.