A word of caution
Many performance cars sold for road use come with an appropriate suspension setup. But if you have modified your car, you may need to make some changes. Do this in stages, and beware. The wrong adjustments can make your car unstable, and increase tyre wear. Remember too that changing one thing can affect something else – if you’re unsure, speak to your mechanic.
Best advice for a road-going car
Make small changes only. Stiffening the suspension will make handling worse if you get it wrong.
After you have added a nice set of wheels, it’s best to install:
- A sports suspension kit
- Adjustable shocks
- Matched progressive springs
If you modify the suspension, you should always have a four-wheel alignment completed on the vehicle.
Some modern cars don’t allow for adjustment of the relevant angles – but many older vehicles do have this ability.
The caster increases the straight line directional control of the front wheels, and returns the wheels to the straight position when you let go of the steering wheel.
When a car goes around a fast corner, its weight is transferred to the outer front wheel/tyre. This creates positive camber – lifting the inner part of the tyre and reducing contact with the road. Set up your car with a slightly negative camber and you will see an increase in tyre contact on the road when cornering. Note: inside tyre wear maybe be increased when doing ‘normal’ driving.
Toe-in means the wheels are angled inwards at the front. Toe-out means the wheels are angled outwards at the front. Generally, ‘zero toe’ is best.
Not so common these days, leaf springs are made of several layers of steel, or single leaves that bend to absorb the up-and-down motion of the car’s axle. They can be modified by replacing them with upgraded springs, and using lowering blocks.
Stiffer suspension isn’t always best on a road car. Springs are designed to keep the car steady – and stop it from bottoming out. Softer springs allow the wheels to move with the chassis. Stiffer sports suspension springs make the ride harder. Add stiffer springs only if you are lowering the car – this will allow for a reduction in travel height. Be aware: lowering the car will also lower the centre of gravity – and reduce the amount of load transfer against the suspension and tyres.
These dampen the travel of the wheels and attached components. The greater the force generated, the harder the shock absorbers will work to slow that motion. Overly stiff shocks won’t allow the wheels to remain in contact with the road. Adjustable sports suspension shocks are recommended – with these, you can alter the shock settings easily.
Sports suspension kits
Buy a sports suspension kit that includes springs and shocks. Don’t fit very stiff/lower sports suspension springs with standard shocks.
If you're looking to make changes to your engine, start with our guide to modifying your car.