Glossary
There are loads of terms that are used to describe suspension and car technology:
- Ackermann
- Camber
- Caster
- Roll Centre
- Scrub
- Scrub Radius
- Slip
- Steering Axis Inclination (SAI) / Kingpin Inclination (KPI)
- Toe in / Toe Out
So why are they important ?
With donor parts taken from a number of manufacturers, chances are when they are assembled together there is much that can be improved with regards to handling.
How do I know what needs changing?
There are some general rules to follow, but as with many characteristic these rules can be contradicted by different road conditions, vehicle weights, tyre set-ups etc. They are for rough guidance only.
Loose Handling Everywhere
Verdict: Very Poor
A car with ‘loose handling’ will be very hard to drive, compensations by the driver will do little to help. Much of the set-up may need changing. Stay with the changes that make the most difference.
- More front spring rate.
- Less rear spring rate.
- More sway bar or sway bar load.
- Lower the panhard bar.
- Less stagger. (circular race track only – involves different tyre diameters)
Tight Handling Everywhere
Verdict: OK but slow
A car with ‘tight handling’ will be easy to drive but will also be slow on the track. Much of the set-up may need changing. Stay with the changes that make the most difference.
- Less front spring rate.
- More rear spring rate.
- Less sway bar or sway bar load.
- Raise the panhard bar.
- More stagger. (circular race track only – involves different tyre diameters)
Loose Entry or Loose Cut Zone
Verdict: Very Poor
A car that has loose handling on entry to a corner will be a handful and may result in lose of speed through the whole bend or ever a spin. It is high priority to fix this.
- More front spring rate.
- Less rear spring rate.
- Less rear weight.
- More sway bar or sway bar load.
- Less rear brake bias.
- Lower the panhard bar.
- Less stagger (circular race tracks only).
- More front shock compression.
- Less rear shock compression.
- Less top link angle (less anti squat).
- More diagonal weight.
- Less trailing arm angle.
- Left Hand Bend : Right Rear
- Right Hand Bend : Left Rear
- Shorter A-arm.
- Left Hand Bend : Right Front
- Right Hand Bend : Left Front
- More toe out.
- More positive caster.
- Add anti dive.
Stable Entry / Tight Cut Zone
Verdict: OK, but may have high driver involvement
Make smaller adjustments and monitor changes closely.
- Less spring.
- Left Hand Bend : Right Front
- Right Hand Bend : Left Front
- More spring.
- Left Hand Bend : Left Front
- Right Hand Bend : Right Front
- Raise panhard bar.
- More rear spring rate or spring below:
- Left Hand Bend : Right Rear
- Right Hand Bend : Left Rear
- Less diagonal weight.
- More stagger (circular race tracks only).
- More front camber if temperatures verify.
- Longer A-arm (maybe add static camber at same time).
- Left Hand Bend : Right Front
- Right Hand Bend : Left Front
- More rear weight.
- More caster split.
- More rear brake.
- Less shock compression.
- Left Hand Bend : Right Front
- Right Hand Bend : Left Front
- More LR shock rebound.
- Left Hand Bend : Left Rear
- Right Hand Bend : Right Rear
Stable Entry / Good Cut Zone / Tight Middle
Verdict: Poor – The driver can make limited compensations.
Make smaller adjustments and monitor changes closely.
- More rear stagger (circular race tracks only).
- Raise panhard bar.
- Less spring.
- Left Hand Bend : Right Front
- Right Hand Bend : Left Front
- More spring.
- Left Hand Bend : Left Front
- Right Hand Bend : Right Front
- More trailing arm angle.
- Left Hand Bend : Right Rear
- Right Hand Bend : Left Rear
- Less diagonal weight.
- More shock rebound.
- Left Hand Bend : Left Rear
- Right Hand Bend : Right Rear
- Less shock compression.
- Left Hand Bend : Right Front
- Right Hand Bend : Left Front
- More Ackerman.
- More spring.
- Left Hand Bend : Right Rear
- Right Hand Bend : Left Rear
- More front camber if verified by tyre temperatures.
- More caster split.
Stable Entry / Good Cut Zone / Loose Middle
Verdict: OK – driver can compensate in some conditions.
Make smaller adjustments and monitor changes closely.
- Less rear stagger (circular race tracks only).
- Lower panhard bar.
- Less trailing arm angle.
- Left Hand Bend : Right Rear
- Right Hand Bend : Left Rear
- More spring.
- Left Hand Bend : Right Front
- Right Hand Bend : Left Front
- Less spring.
- Left Hand Bend : Right Rear
- Right Hand Bend : Left Rear
- Less rebound.
- Left Hand Bend : Left Rear
- Right Hand Bend : Right Rear
- More compression.
- Left Hand Bend : Right Front
- Right Hand Bend : Left Front
Stable Entry / Good Cut Zone / Good Middle / Tight Acceleration Zone
Verdict: OK – driver can make limited compensation in some conditions.
Make smaller adjustments and monitor changes closely.
- Less top link angle.
- Slightly more stagger (circular race tracks only).
- Small raising of panhard bar.
- Slightly more trailing arm angle.
- Left Hand Bend : Right Rear
- Right Hand Bend : Left Rear
- Slightly less diagonal weight.
- More shock rebound.
- Left Hand Bend : Left Front
- Right Hand Bend : Right Front
- More shock rebound.
- Left Hand Bend : Right Front
- Right Hand Bend : Left Front
- More shock compression.
- Left Hand Bend : Right Rear
- Right Hand Bend : Left Rear
- Less shock compression.
- Left Hand Bend : Right Front
- Right Hand Bend : Left Front
- Slightly less spring.
- Left Hand Bend : Right Front
- Right Hand Bend : Left Front
- Slightly more spring.
- Left Hand Bend : Right Rear
- Right Hand Bend : Left Rear
Stable Entry / Good Cut Zone / Good Middle / Loose Acceleration Zone
Verdict: Poor – High driver involvement
Make smaller adjustments and monitor changes closely.
- More top link angle.
- Less stagger (circular race tracks only).
- Lower the panhard bar.
- Less trailing angle.
- Left Hand Bend : Right Rear
- Right Hand Bend : Left Rear
- More diagonal weight
- Left Hand Bend : More Left Rear spring. (race cars – Right Rear spring softer than Left Rear spring by 10% +/-.)
- Right Hand Bend : More Right Rear spring. (race cars – Left Rear spring softer than Right Rear spring by 10% +/-.)
- Less shock rebound.
- Left Hand Bend : Left Front
- Right Hand Bend : Right Front
- Less shock rebound.
- Left Hand Bend : Right Front
- Right Hand Bend : Left Front
- Less shock compression.
- Left Hand Bend : Right Rear
- Right Hand Bend : Left Rear
- Less Ackerman.
- More spring.
- Left Hand Bend : Right Front
- Right Hand Bend : Left Front
- Bigger sway bar or more sway bar load.
Stable Entry / Good Cut Zone / Good Middle / Good Acceleration Zone / Tight Exit
Verdict: Good – In warm conditions with good tyres this can be ideal.
Check handling in all conditions before making small adjustments. Monitor changes closely over a period of time.
- Slightly less top link angle.
- Slightly more stagger.
- Small raising of panhard bar.
- Slightly more trailing arm angle.
- Left Hand Bend : Right Rear
- Right Hand Bend : Left Rear
- Slightly less diagonal.
- More shock rebound.
- Left Hand Bend : Left Front
- Right Hand Bend : Right Front
- More shock rebound.
- Left Hand Bend : Right Front
- Right Hand Bend : Left Front
- More shock compression.
- Left Hand Bend : Right Rear
- Right Hand Bend : Left Rear
- Less shock compression.
- Left Hand Bend : Right Front
- Right Hand Bend : Left Front
- More Ackerman
- Left Hand Bend : Slightly more Right Rear spring (race cars – Reduce spring split in rear to 5% stiffer Left Rear or to equal rears).
- Right Hand Bend : Slightly more Left Rear spring (Reduce spring split in rear to 5% stiffer Right Rear or to equal rears).
- Slightly less RF spring.
- Left Hand Bend : Right Front
- Right Hand Bend : Left Front
Stable Entry / Good Cut Zone / Good Middle / Good Acceleration Zone / Loose Exit
Verdict: Poor – Slow, loose exit from corners will require high driver involvement.
Make smaller adjustments and monitor changes closely.
- More top link angle.
- Less stagger (circular race tracks only).
- Lower the panhard bar.
- Less trailing arm angle.
- Left Hand Bend : Right Rear
- Right Hand Bend : Left Rear
- More diagonal weight
- Left Hand Bend : More Left Rear spring. (race cars – Right Rear spring softer than Left Rear spring by 10% +/-.)
- Right Hand Bend : More Right Rear spring. (race cars – Left Rear spring softer than Right Rear spring by 10% +/-.)
- Less shock rebound.
- Left Hand Bend : Left Front
- Right Hand Bend : Right Front
- Less shock rebound.
- Left Hand Bend : Right Front
- Right Hand Bend : Left Front
- Less shock compression.
- Left Hand Bend : Right Rear
- Right Hand Bend : Left Rear
- Less Ackerman
- Left Hand Bend : More Right Front spring (race cars – If Left Front is stiffer than Right Front think about equal fronts or softer Left Front).
- Right Hand Bend : More Left Front spring (race cars – If Right Front is stiffer than Left Front think about equal fronts or softer Left Front).
- Bigger sway bar or more sway bar load.
Stable Entry / Good Cut Zone / Good Middle / Good Acceleration Zone / Good Exit
Verdict: Excellent.
Put your spanners away and DRIVE IT!