12 Modifications To Improve Car Performance

Modifications, customisations or retuning of vehicles continue to grow in New Zealand. These modifications can be broadly categorised as performance modifications, aesthetic/ cosmetic modifications or functional modifications. In this article we will focus on some of the performance modifications where the primary purpose is to enhance the power, handling and/or fuel efficiency of the car, ute, van or motorcycle.

Cold Air Intake

Cold air is denser than hot air with closer oxygen molecules. A cold air intake improves the airflow in the engine which when combined with fuel creates more efficiency and power. This consists of replacing the stock air filler box for the car’s intake. The engine can handle more fuel into the cylinders and by allowing cold air to flow naturally, the engine breathes easier and able to access more air when needed for higher horsepower.

Cat-Back Exhaust

It’s a good idea to upgrade the exhaust system particularly if you do an intake upgrade. A high performance exhaust system helps the air to escape more efficiently from the engine, enhancing horsepower. This system replaces the stock exhaust pipe and muffler and is installed behind the catalytic converter. Depending on personal sound preference, the stock muffler could be replaced with a chambered muffler, straight-through/ glasspack muffler or a turbo style muffler. In simple terms, muffler sound can be configured based on which sound waves die and which are allowed to escape and be heard.

ECU Program Remapping

The Engine Control Unit (ECU) is mapped by manufacturers to control the fuel-air mixture in the engine to pass emission standards, for the best L/100 kms (litres per 100 kms) and the resultant optimum power.  Not all cars are designed for this modification, however where it is possible, it can be a self-service tune or a custom-built Dyno tune by a specialist. An ECU mapping modification can unleash the car’s full potential for horsepower and torque by allowing maximum amount of fuel into the combustion chamber. This may however involve disregarding emission standards and fuel economy.

Sway Bars

Also known as a stabiliser bar or anti-roll bar, an adjustable sway bar connects the suspension to the body of the vehicle. The stiffer the sway bar, lesser the understeer for a front-wheel drive and oversteer for a rear-wheel drive. The reduced body roll and thus a flatter car body on sharp turns leads to better performance.

Strut Tower Braces

The strut tower braces or strut bars connects to the top of the strut towers and controls chassis flexing providing a more stable foundation for the car’s suspension during high speed turns. This enables the tyres to be flat on the ground, increasing contact with the road surface and thus better traction and handling.

Engine & Transmission Mounts

Original rubber mounts are upgraded to polyurethane mounts or solid motor mounts for better engine response time. The torque induced engine movements can be minimised with improved throttle response and more power to the car. The trade-off is more noise as the stiffer mounts absorb lesser noise. Solid motor mounts are best used for drag cars or rally cars.

Short Shifter

Replacing the stock shifter with a short shifter or race shifter makes it easier and faster to get through the gears. As it has more precision, it is better than short shifters when racing, driving in congested places and going uphill.

High Performance Tyres

High performance tyres are made of a softer compound making it quicker to warm up to grip the road better, improved handling and meet higher speed demands.

Disk Brakes

Disk brake systems with superior stopping performance compared to drum brakes are less likely to fail from overheating and dry quicker when wet. Speed is what racing is all about and disk brakes allow the vehicle to drive deeper into the turn and apply higher braking force at the last possible moment without overheating the disk brake components.

Racing Wheels

Compared to the traditional steel wheels, alloy wheels or ‘mag wheels’ are lighter and improve vehicle performance and handling. They dissipate heat better providing better braking performance.

Performance Cam Shafts

These allow more air to enter the engine and for more exhaust fumes to exit out of the engine. Performance cam shafts have larger cam lobes increasing the duration and for maximum lift. This makes a significant difference to the vehicle’s engine power.

Major engine upgrades

For a more reliable vehicle, major engine upgrades is the most technical of the modifications mentioned in this article. These can include engine block reboring, refacing or honing; crankshaft regrinds, polishing and crack testing or even a complete engine overhaul.

There are more modifications that will marginally or significantly improve vehicle performance. At some point, we will cover those too. In the meanwhile the highly experienced team at Engine Specialties are on hand for practical advice and to carry out your vehicle modifications.