Your Guide To Car Tuning

Posted on November 29th, 2013 by GEM Motoring Assist

Car tuning is extremely popular but Rob Marshall argues that the uninitiated motorist should research the topic carefully to avoid not only wasting money but also damaging the car.

Car tuning guide

Ever since the motor vehicle was invented, enthusiasts have devised ways to improve it. Although engines can be tuned to improve both their economy and efficiency, most alterations are made to enhance performance, especially in terms of maximum speed and acceleration. However, there are compromises with engine tuning, which can reduce both the flexibility of the unit and also the lifespan of its components.

Car tuning guide

With car tuning, you need to establish your priorities first, as the needs of a fast-road car will differ wildly from those required by a competition vehicle. A fully-prepared rally competitor, for example, can be almost undriveable in city traffic. Plan for a tune-up before you start serious engine tuning.

You should not develop an obsession with horsepower figures. With successful car tuning, you still have a vehicle that remains flexible and powerful throughout the engine’s rev-range.


Before investing your money in engine tuning, have your car serviced. A careful tune-up will ensure that it is running at its optimum efficiency. Ask your technician to ensure that critical items, such as the fuel injectors or carburettor(s), are operating correctly and that the engine is in good mechanical order. Do not waste money on engine tuning if the power-plant is worn-out.

To obtain the best balance between power gains and cost, it is worth investing in both an induction kit and an improved exhaust system. Less energy will be wasted in drawing air in, and the waste exhaust gases will be extracted more efficiently.



Many performance exhaust systems are best fitted in their entirety. A missing catalytic converter, on a vehicle that had one fitted from new, will cause an MoT Test faliure. Bare this in mind, should you buy a car that has been modified already.

 Car tuning

Car tuning: A free-flow air filter kit is a worthwhile investment.

Modern cars have their engines controlled by Electronic Control Units (ECUs), computers that control how the engine runs, according to the conditions that it is faced with. A complete “map” of parameters is stored within a computer chip, and experienced car tuners can modify the original map setting and tailor it to a specific engine. The result is often a significant increase in both fuel economy and engine performance. Generally, the largest benefits are realised from turbocharged engines, which includes most modern diesel cars.

To establish whether any power gains are being realised from engine tuning, a car should be checked on a professional rolling road, known as a dynamometer.

As increasing an engine’s power will put extra strain on its internal parts, more advanced car tuning will involve dismantling the engine and fitting modified components. The extent of this does depend on the level of power that the engine is expected to produce.

Advanced engine tuning demands that the unit be dismantled and its parts lightened and balanced by experts in bespoke machining workshops.


Remember that other safety-related items, such as the brakes, suspension and tyres, may also require upgrading. You must also inform your insurance company of any modifications and it is advisable to check, before investing in any kind of engine tuning, how much your premium could be affected. Finally, you should check that any modifications are not invalidating any new or used car warranty.


As part of your engine tuning project, other components may have to be changed, such as brake and clutch parts. Pictured is a standard Porsche clutch plate (left), against a high-performance alternative (right).