Modern suspension systems can seem complicated, but many of the principles involved date back to the early days of automotive development. Here, we try to cover some of the most common questions we get asked about suspension upgrades.
There is no single set of answers which apply to every vehicle and suspension type though, so this is intended as a general guide only.
“How much lift can I get?”
We are constantly being asked for lifts of 2 inches or more, and while this is fine for some vehicles, it will cause a lot of problems with others. Specialist brands such as Old Man Emu and Terrain Tamer spend a lot of time and money developing and testing their products and trying to find the best balance between amount of lift, vehicle stability, off-road durability, drivetrain alignment and ride quality both on and off-road.
Adding any amount of lift to a vehicle will raise the centre of gravity, but most premium suspension packages are designed to be suited to daily use and are comfortable and stable. However, adding a larger amount of lift, typically 3 inches or more, can make the vehicle less stable in cornering, less pleasant to drive, and less useable – both on and off-road.
“What tyre size can I fit?”
When fitting larger wheels and tyres, we always recommend taking measurements to be sure that your chosen tyre size will fit without contacting the vehicle body or other components. This should be done after adding any additional weight (such as winches, bumpers, roll cages, etc) and after upgrading your suspension. It is never a good idea to buy your wheels and tyres first – and then have to upgrade your vehicle to make them fit.
“Is factory suspension the best option for my vehicle?”
Although it seems logical that all vehicle manufacturers would fit the perfect suspension when the vehicle is new, this is often not the case. Firstly, most vehicles are built to a price-point, so components are often developed to achieve the best results within that price point. Secondly, 4×4 vehicles and pickup trucks have a wide range of uses, and very few manufacturers have ever catered for this by offering upgrades such as different spring rates or shock absorber valving.
Depending on vehicle age, differing usage patterns and mileage covered, factory suspension components become fatigued and less efficient, corrosion can set in, and safety issues can arise. When this happens, it may be difficult or prohibitively expensive to obtain OE replacement parts.
“Can I just replace part of my suspension?”
While it may be tempting to economise and just replace the springs on an older vehicle to achieve some lift, or to just replace one or more shock absorbers to overcome an MOT failure, this is usually not recommended. A set of new springs will not give the best results if they are paired with worn-out shock absorbers – and doing so will cause the replacement springs to work harder and therefore fail sooner. Likewise, fitting new shock absorbers will not cure worn-out springs and can reduce the lifespan of your new shocks.
“Are my shock absorbers long enough?”
Fitting an integrated replacement suspension kit will normally ensure that the shock absorbers are the correct length for the supplied coil or leaf springs. However, if you fit lift springs with your existing factory shocks absorbers, in some cases the shocks can be too short and can ‘top out’ at full extension. This varies by vehicle.