Frowned upon by motoring purists, embraced by boy racers – this was how car tuning was seen not too far back. But how times have changed. Tuning, in the widest sense, encompasses all the modifications to a vehicle with the end purpose of improving performance. And it means different things to different people. This can range from a simple ECU remapping, taking the same time as a regular oil change, to a complete engine tuning, chassis and body rework and a work in progress.
Basics of Engine Tuning
A car tune is most often done to the engine. Here there are various parts that can be swapped out for something better. Better air intakes, improved exhaust parts and spark plugs, combined with a quick-spinning turbo for better combustion. These changes to the stock engine can be carried out independently of each other, or as a whole. It all depends on how much you`re willing to spend and the performance gains you`re after. If you`re serious about going all-out, then the engine internals are next on the list. Just remember, once you start swapping out parts, there`s no going back.
To supplement the increase in sheer engine power, other parts are also often replaced. These include brakes, tyres, the suspension, the transmission and bodywork. This means better grip, shorter stopping times, stiffer and more responsive steering, quicker gear changes and a lighter vehicle with better aerodynamics.
Carmakers today produce vehicles that need to meet strict emissions and acceptable fuel consumption. There are also considerations about engine longevity. Stock engines can produce far more bhp than the quoted figures but are hindered by the factors above. Car tuning has come about to tap into this unused power.
Air Intakes
More combusted air means a bigger bang and more power. Stock intakes are designed to limit air low both by the type and size of the air filter and air cleaner box. Performance vehicles can benefit from different combinations of intake kits, including dual air filters, air boxes and panel mounted scoops all designed from lightweight yet extremely strong materials like carbon fibre to maximise airflow efficiency and release the roar of the engine when the pedal is down. Better acceleration is a given.
Exhausts
Air intake kits are combined with improved exhaust parts. Increased pressure and heat during combustion, aided by more available air, need more space to work with on their way out. This can include modifications or replacement of the exhaust manifold, the exhaust tubing, catalytic converters, mufflers, and on diesels the DPF filter. Performance manifolds will reduce potential backpressure, limiting how much of the combusted gases make their way back into the cylinder. Airflow is further improved with straighter wider tubing from the catalytic converters down to the larger mid-section pipes. Bends in mufflers are reduced, and silencers less effective than your stock exhaust, but in a good way. You get a deeper, fuller exhaust note.
Different types of exhausts are sold. The best performance gains are from header back systems, with tubing from the exhaust manifold. Cat-backs change everything from the converter down and axle backs include exhaust replacement in the mufflers, tailpipes and exhaust tips. Turbo-specific units are also sold.
Performance exhausts are made of high-end titanium or carbon fibre, meaning weight savings over stock steel. Titanium tubing better handles increased temperatures and pressure than regular stainless steel.
Turbocharging
Exhaust gases are reused to spin turbines at mind-boggling speeds. This activates a compressor, forcing fresh air in for combustion. Though most performance cars will already have stock turbochargers, due to the trend in lowering engine displacement in accordance with emissions regulations, you can install a bigger, beefier turbo. Intercoolers are also used, to regulate the pressure and temperature of the new air. As are more sophisticated units, like twin turbos that activate at different rpm to keep feeding the engine. Replacement turbos will be better made, work under higher loads, and provide the biggest performance gains. They can also be added to naturally aspirated engines.
ECU Mapping and Fuel Management
Even basic engines, like smaller turbo diesels can be tuned. This is a large portion of cars in the UK. Simple software remapping of the ECU, the unit that controls various electronic systems in your car, can add a significant boost in power. Remapping changes preset manufacturer parameters in terms of how much fuel is injected in for combustion and at what time. Sensors in the intake manifold provide data about the amount of air present, and the ECU adjusts the fuel injectors accordingly. ECU remapping is one of the cheapest car tune solutions. It optimises power and provides for better fuel consumption.
Spark Plugs and Ignition
When more air is present in the engine, a bigger initial bang is required to bring on combustion. If you`ve already changed to better air intakes and remapped the ECU, then the next logical step would be to replace the stock spark plugs. Plugs with higher heat handling can better cope with the increase of injected fuel and in air pressure and temperature. Timing of the spark is crucial as well, to avoid misfiring or knocking. Again, this is adjusted by changes to the ECU software.
Engine Internals
It is not uncommon to replace the internals like crankshafts, cams and camshafts, pistons, valves, cylinder heads and connecting rods to parts that have the higher tensile strength to bear increased friction, heat and rotational forces. Materials will be better and can improve the life of the engine. You`ll often see these to be the first parts replaced in engine rebuilds and resto-mods.
Other Performance Changes
Though tuning is mostly done to increase engine power, the rest of the vehicle also needs replacement of stock parts to better balance improved performance. Bigger rotors and callipers with grippier pads mean your car will now have adequate stopping power. Maintaining more speed in turns and braking later will improve lap times significantly. These upgrades are also good for better braking in wet conditions.
Suspension upgrades mean better shocks and springs, all sitting on uprated upper and lower control arms. The result is a lower, stiffer chassis that is easier to throw around. For additional strength add anti-roll bars. You do however sacrifice some comfort from the stock setup to get the sportier feel.
Suspension and brakes upgrades are done along with fitting grippier tyres set on lighter alloys. You get more feel through the steering wheel, meaning better control and response times.
Lastly, there`s a multitude of body kits that can be added or replaced to get better aerodynamics and lower drag at higher speeds. Rear spoilers and diffusers increase downforce, literally gluing the car to the road. Side skirts installed under the doors serve a similar purpose. Side mirror deflectors reduce wind resistance and noise from mirrors. Lightweight carbon fibre bonnets, bumpers and roofs provide substantial weight savings over stock parts. You`ll find body kits in various combinations to suit your car.
Car Tuning Considerations
Stock engines can handle only as much modification, without running into costly repairs afterwards. Tuning specialists are the best place when searching for better performance from your vehicle. They can provide moderate upgrades or any number you have in mind, and also professional advice as to the parts to install. Newer performance cars can handle more upgrades, but be willing to spend to get the best results.