Common Vehicle Performance Upgrades

Since the early days of the automobile, enthusiasts have been trying to get more performance from their vehicles to make them faster than everyone else on the road. For many of us, this started with our first vehicle and has grown with every new project. Customizing and upgrading vehicles deepens our love for our cars, but it may be difficult to figure out where to start or what parts you need. However, one thing we know is that we need to upgrade parts to see better performance, and that is where aftermarket performance parts come in. Performance parts replace original factory equipment and are designed to increase overall vehicle performance by adding horsepower, improving handling, or increasing stopping power in a vehicle. Knowing where to start or what upgrades can be done may be a difficult process, so read on for some ideas to help you start improving your performance.

The first place most people start upgrading their vehicle is the engine. Increasing horsepower and engine response provides the most noticeable gains in performance. Deciding how much performance you want from your vehicle will help you decide how extensive the upgrades need to be. Some upgrades can be performed by simply changing out external parts of the engine, but some may require partial or full engine disassembly and could be daunting for those without experience. Since disassembling and reassembling an engine can be extensive and may require special knowledge, we will focus mainly on external engine upgrades, bolt-on performance parts, and complete engine swaps in the examples below.

Crate Engines

Building a performance engine can be one of the largest tasks when upgrading your vehicle. It can take countless hours to determine the exact parts you may need to complete the engine modifications you are trying to achieve. This can be daunting for even the biggest car enthusiast, but there is another option. Buying a drop-in ready crate engine instead of rebuilding or upgrading the engine that is already in your vehicle may be the best option for you.

Crate engines are fully-assembled and balanced engines which are designed to meet a specific horsepower and torque output that is significantly higher than a stock engine. The improved performance is achieved by upgrading all of the internal moving parts, such as the camshaft, crankshaft, pistons, valves, valve springs, rods, and bearings. These upgrades are designed to work together to create higher compression and more complete combustion in the cylinders while strengthening internal parts to withstand the higher compression and increased power. Depending on the configuration, many crate engines include the intake and carburetor or throttle body, and may also include the distributor or ignition coils. Depending on the crate engine you purchase for your vehicle, you may still need to purchase an appropriate wiring harness, ECU (engine control unit), pulleys, exhaust manifolds, and sensors to complete the installation and ensure the engine runs at its best.

Supercharger Kits or Turbo Kits

A supercharger or turbocharger, commonly known as a turbo, are forced air induction systems that can dramatically increase the power output of an engine. Both force air into the engine, commonly referred to as boost, to increase power. Superchargers and turbochargers have different ways of creating boost, and knowing which unit will work best for your vehicle can help you get the maximum power from your engine.

Superchargers, or blowers, are driven by a belt connected to the crankshaft which turns rotary vanes in the supercharger to push air into the engine. This allows a supercharger to deliver a quicker power boost when compared to a turbo. Superchargers are most commonly used with larger-displacement engines, such as large-block V-8 engines, and in most cases mount to the top of the engine where the air intake is normally located. While you will see large overall power gains from a supercharger, you may not see an increase equal to the horsepower rating of the unit. This is due to a small power loss that is caused by the engine turning the belt of the supercharger, just like the power loss experienced when the engine turns an alternator or A/C compressor. Don’t let that deter you from considering a supercharger, because, in most cases, the gains from the supercharger outweigh any negative impact from the belt drive.

Turbos use power from the engine exhaust to spin a turbine that creates the pressured boost and increased airflow into the engine. A turbo can yield large power increases, and can be especially beneficial to smaller displacement 4- or 6-cylinder engines. Turbos do not experience the power loss of superchargers since they are not driven by the engine. However, they experience what is commonly known as turbo lag, since it takes a moment for the turbo to spool up as the engine RPMs and exhaust volume increase. In most cases, the turbo lag may not be noticeable or is barely noticeable unless your vehicle is set up to race or requires a large amount of boost. Regardless of which setup you choose for your vehicle, make sure you install a complete system to prevent damage to the engine and get the maximum power increase from the supercharger or turbo. You can read more about the differences and benefits of turbos and superchargers in our article.

High-Flow Exhaust System

High-performance engines require more air and fuel to create power. Just like limiting restriction in the intake system boosts power, reducing restrictions in the exhaust system can yield similar benefits. Along with an upgraded air intake, a high-flow exhaust system is an excellent option to increase the performance of your engine. This type of exhaust is designed with catalytic converters and mufflers that allow exhaust to leave the engine more easily and at a higher velocity, and normally include larger-diameter exhaust pipes to permit a higher exhaust flow rate. Many enthusiasts also add exhaust headers when upgrading to a high-flow exhaust system. Headers are designed to match the flow of an upgraded exhaust to create a less restrictive path for exhaust to leave the engine.

While a high-flow exhaust system helps an engine breathe, and usually adds a performance sound to the exhaust, this doesn’t mean you should put the least restrictive exhaust on your vehicle. Engines require some resistance, called backpressure, from the exhaust to achieve optimal performance. If there isn’t enough backpressure from your exhaust, you will likely see a loss of power and performance instead of a gain. Make sure to research the high-flow exhaust system options available for your vehicle to match and complement the performance of your engine so that you can get the increase in performance and exhaust sound you desire for your vehicle.

ECU Tuning

The engines in all modern cars are controlled by a computer called the ECU (engine control unit) or ECM (engine control module). Because of the increased use of computers in vehicles, ECU tuning has become a common way to increase vehicle performance. Also known as engine tuning, car tuning, or performance chip tuning, ECU tuning allows you to adjust the engine timing, idle speed, air-fuel ratio, and more to get the optimum performance from the engine in your car. To correctly tune the ECU, you will need either a diagnostic tool with the ability to reprogram or “flash” the ECU, or you will need a tuner or analyzer that will give you live engine data and allow you to tune the engine in real time. Tuning the ECU can provide a limited performance increase on a stock engine, but it can deliver maximum performance when used in combination with other engine upgrades.

Performance Spark Plugs and Spark Plug Wires

A strong spark, also commonly called a “hot” spark, in the cylinders of your engine is necessary for optimal performance. One of the easiest ways to ensure you have the right amount of spark is with performance spark plugs and spark plug wires. Knowing what spark plugs you need for your engine can be a little confusing due to the variety of different types of spark plugs on the market. The type of spark plug you may need to get the best performance from your engine may come down to trial and error, but performance spark plugs are designed to work with high-output power distribution and air/fuel delivery specifications. Older engines that use a carburetor and a distributor with a distributor cap and rotor bug often achieve the best performance using racing spark plugs with large copper cores. On the other hand, newer engines that use individual ignition coils and fuel injection systems usually perform the best with Iridium spark plugs. Whatever spark plug works best in your engine, always remember to check your service manual for the correct spark gap, and make sure to gap each spark plug before installation. This is the best way to ensure you have the best spark for optimal performance.

Performance spark plug wires are made with copper or graphite cores that are larger than standard spark plug wires, and feature stainless steel or zinc-plated steel terminals for optimal conductivity. This allows for maximum power transfer and reduced power loss from the coil or distributor to the spark plug. Plus, most performance spark plug wires use special jacket material, like silicone or EPDM, to insulate the wire core to protect it from heat damage and prevent arcing along the wire. When you pair performance spark plug wires with the right spark plugs, you can get a hot enough spark for more complete combustion in the cylinder, creating optimal performance from the engine. This can also be further improved using performance distributors, coils, coil packs, and other ignition upgrades, depending on the type of vehicle you’re working on.

After adding power and performance to the engine, the logical next step is to upgrade the drivetrain to get more power to the wheels. The drivetrain delivers the power provided by the engine through the transmission, driveshafts or CV shafts, and drive gears to get power to the ground. The type of drivetrain is commonly determined by the wheels that drive the vehicle, such as front-wheel drive, rear-wheel drive, or all-wheel drive. There are several ways to add drivetrain performance from the transmission to the wheels, but we are going to focus on a few of the most common upgrades to the transmission.

Performance Flywheels

Reducing weight and adding strength are always a good thing when upgrading the performance of your vehicle, especially in the drivetrain. Performance flywheels are made from lighter and more durable materials than stock flywheels. These stronger flywheels allow performance starters to turn over and start higher-compression engines, and allow the engine to rev quicker, transferring more power to the wheels by reducing power loss because they are lighter and take less power to turn. This makes a performance flywheel an excellent place to start your drivetrain upgrade.

Shift Kits

Any car enthusiast has probably heard someone mention putting a shift kit in a transmission, but that description may not explain what the kit really does. Most stock automatic transmissions are designed for smooth, comfortable shifts, which is accomplished by the transmission overlapping shifts and being in two gears at once during the shift. While it may be more comfortable for your transmission to shift smoothly, it can actually be hard on a transmission and decrease fuel efficiency.

A shift kit includes plates and seals which alter the flow of transmission fluid through the valve body to create firmer shifts and improve efficiency. The kit also reduces restrictive oil flow, which results in reduced slippage and shift overlap. It may be less comfortable to drive with firmer shifting, but it allows transmissions to operate as designed and achieve faster gear changes. The reduced slippage also allows the transmission to send more power to the wheels and may improve fuel efficiency, but the primary purpose of a shift kit is to help a vehicle jump off the line and shift quicker to get up to speed faster. This can be especially useful in racing applications and is a common performance upgrade for vehicles with automatic transmissions.

Performance Torque Converters

The torque converter is likely one of the most misunderstood parts of an automatic transmission. The torque converter in an automatic transmission effectively takes the place of the clutch that would be found in a manual transmission. At the most basic level, a torque converter is a fluid coupling attached to the flexplate which allows the transmission to be separated from the power coming from the engine so that the engine can still run while the vehicle is sitting still. When you release the brakes and press the gas pedal to increase the RPMs, the fluid pressure builds in the torque converter and begins to transfer power from the engine to the transmission to move the vehicle.

When it comes to performance torque converters, many enthusiasts may refer to them as “stall converters”, and you may wonder, “what does stall really mean?”. The easiest way to describe stall in a torque converter is based on the RPM limit it takes to hold back the engine speed while the transmission output is limited. You can think of it like holding the gas pedal and brake pedal at the same time, and the stall indicates the RPMs at which the tires begin to spin. For example, if your vehicle creates the most power at and the wheels start to move at 2,400 RPM, your torque converter probably has a stall range of 2,300 - 2,500. While that is not an exact way to determine the stall for your engine, and is not the recommended way to discover the stall, it can help you better understand the stall range for your vehicle. High-stall torque converters are what allow some cars to stand still while the engine is revved to get the best launch while drag racing. If you do not match the stall to your engine power band, you will actually see a loss in performance, especially when accelerating from a stop. In some cases, you may need to have your vehicle tested on a dynamometer, or dyno, to find the appropriate stall range and correct performance torque converter for your vehicle.

You may think you're done once you have your engine and drivetrain upgraded and ready to perform, but don’t forget that better performance often changes the vehicle's handling. While many newer vehicles leave the factory with a “sport” suspension, the suspension can quickly become overwhelmed with even minor performance upgrades. You can upgrade the suspension on your vehicle with sport or race suspension components to combat body roll and any other negative effects you may notice after your other vehicle performance upgrades.

Shocks, Struts, and Springs

The foundation of any good suspension is shocks, struts, and springs. Most stock suspensions are designed to only meet the expected handling and safety conditions for the vehicle when it leaves the factory. Shocks, struts, and springs work together to create a comfortable and desirable ride, depending on the type of vehicle you drive and where you drive. Upgrading the suspension components to sport or racing suspension parts stiffens the ride of the vehicle, but they can make the ride more responsive and help reduce body roll while cornering to maintain proper tire engagement with pavement. Many shock, strut, and spring upgrades will also lower the ride of the vehicle from a half inch to 2.5 inches, lowering its center of gravity and further reducing the body roll experienced in the vehicle.

To achieve maximum suspension performance, many enthusiasts choose coilover shocks, often simply called “coilovers,” to replace the stock shocks and struts. Coilovers, at the most basic level, are a combination of shocks and springs designed to handle cornering and terrain better than stock ride control or suspension components. Most coilovers also offer height adjustment so you can find the perfect handling balance for your vehicle. The primary consideration when determining how far to go with your suspension upgrades is the desired comfort of your ride. The stiffer you make the suspension for performance or racing, the less smooth and often less comfortable the ride will be during daily driving.

Sway Bars

Sway bars, also known as anti-roll bars, reduce the body roll of a vehicle by connecting the suspension control arms on opposite sides of the vehicle. The sway bar is under constant tension and acts like a spring to even out or prevent body roll and keep the vehicle more level. Upgrading to a larger sway bar is one of the best upgrades to improve the handling of any vehicle, and they can be upgraded with little or no change to the comfort of your ride. A better sway bar can even help your family sedan or coupe corner better than ever, or make flat-out cornering possible in your performance vehicle. Adding more agility, stability, and responsiveness to your vehicle is easy by upgrading or adding an appropriate performance sway bar and upgraded sway bar links or bushings.

We hope this has helped you understand some of the most popular upgrades to increase your vehicle's performance. The products listed in this article are only a few of the ways you can increase the performance of your vehicle. These and many other options may require extensive assembly or disassembly of the engine or other vehicle systems, and we would be happy to recommend a trusted local repair shop if you are not comfortable performing any of these upgrades. You can also check out our performance parts section to find the parts you need to upgrade your vehicle. As with any vehicle modifications, you may need to consider checking to see if any upgrade will void your vehicle warranty, as well as ensuring that you are abiding by local laws and can continue to operate your vehicle legally on the street. No matter what performance upgrades you make to your vehicle, always remember to drive safely and get to know your new and improved vehicle to ensure your continued safety and enjoyment.