How to lower your car

Posted on June 10th, 2016 by Rob Marshall


Unlike many aftermarket engine modifications, lowering your suspension is not illegal, at least, for the moment. Yet, there remain many examples of poorly-executed modified suspension systems out there (see our main picture for a typical example), many of which destroy the vehicle’s ride quality, while some cars may even be rendered dangerous, by the innocently-intentioned geometry changes.

Yet, sensibly-lowered suspension can be beneficial, as it is intended to lower the car’s centre of gravity, so that the car does not lean as much into corners. Partnering with the experts Spax Performance, the following tips should be of use, if you are considering reducing your car’s ride height.

Consider your situation and bear in mind that standard suspension set-ups are designed to be a compromise. However, if you do not carry heavy loads (including additional passengers) and prefer greater stability for speedier cornering, lowering the car and adjusting the suspension’s spring and damping rates might prove beneficial. Speak to a suspension specialist, such as Spax Performance, which will provide useful advice.

Resist lowering your car too much. The restricted remaining suspension range can cause the suspension, wheels and tyres to make contact with the bodywork and upset the handling balance. Generally, consider lowering the car no more than 40mm, which will still provide an adequate range of suspension motion for most situations.

Ride comfort. Progressive springs and dampers should accompany lowering but such systems can be between 25 and 40% stiffer than the standard set-up, which will affect compliant ride quality. Therefore, the modification may make longer cross-country journeys more tiring on the driver.

Never cut springs. While a simple and inexpensive method of lowering a car involves removing and cutting several coils from the car’s springs, resist the exercise. Not only is the coil at a greater risk of breaking free from its mounting but the standard dampers will also be operating outside of their normal ride height positions, in normal driving, compromising their effective performance.

Bump Stops – Not only do bump stops prevent damage, should the suspension and bodywork make contact, they also assist the spring rate, as the suspension reaches the limits of its travel. Always replace bump stops with standard-specification parts.

Adjustable dampers – These units can have their ride quality and damping performances adjusted, often by a screw on the damper unit itself. Such parts can be beneficial for cars that tow heavy loads, when fitted to the rear.

Tyres – Tyres also provide an additional springing medium and it is possible to lower a car slightly, by fitting lower profile covers. However, this means that the springs and dampers will no longer work in harmony with the original tyre specifications. Therefore, it is not recommended. Incidentally, tyres that have been ‘stretched’ to fit wider rims are illegal.

Alignment – Adjusting vehicle ride height will also affect the suspension alignment, specifically, the front wheels’ tracking and even camber settings, which will require adjustment, once the modification has been completed. Four Wheel alignment is especially beneficial for rear and four-wheel-drive cars.

Know the limits – If you are unsure whether or not you will be able to perform the work at home, consult a specialist. Also, be aware that lowering certain active, adaptive, fluid and air suspension systems may present a safety risk.

Insurance – As with any modification, always inform your insurer of any changes. Should you be uncertain about a premium increase, ask before you commence the changes.