How to Add More Horsepower to My Cars

by Contributing Writer; Updated June 12, 2017

Improving the horsepower of a car or truck via aftermarket modification is one of the great joys of owning your vehicle. Although the market for performance aftermarket parts is primarily geared towards sports cars, nearly every vehicle has at least some performance aftermarket options available which increase horsepower. The specific parts, costs and respective increases in horsepower will all depend on the make, model and year of your truck.

Under The Hood:

 How to Add Horsepower to a Dodge Charger

Tune the Charger using a hand-held tuner. Tuners modify the internal computer of the Charger, which controls many electronic processes of the vehicle. Using a tuner can provide a mild horsepower boost on even an unmodified Charger, but the use of a tuner is essential when installing other performance modifications. Tuning your Charger will allow it to take advantage of any other modifications you perform and maximize the horsepower increases provided by other aftermarket parts.

Install a high performance cold-air intake system. Stock cold-air intake systems are designed for economy rather than performance, and an increase of 8 to 15 horsepower can be had by replacing the stock intake system with a performance aftermarket intake system. The exact horsepower gain will depend on the make and model of the intake system as well as on the engine your Charger has. Larger engines with mroe cylinders typically experience larger gains in horsepower from aftermarket modifications.

Replace the stock exhaust system with a high-flow performance exhaust system. Stock exhaust systems are relatively restrictive in order to keep the cabin of the vehicle quiet. A high-flow aftermarket exhaust system will increase the airflow allowed by the exhaust and substantially increase the horsepower of your Charger. Note that this modification will also increase engine noise, and should only be performed if you are comfortable with having a louder, more aggressive exhaust note on your Charger.

Install a supercharger or turbocharger kit. Superchargers and turbochargers are slightly different forms of forced air induction systems, which funnel vast amoutns of air into the engine of the Charger. These modifications are complicated and expensive, but they can produce massive power boosts of over 100 horsepower in some cases. These installations should only be performed by a trained professional as they have the potential to cause extreme damage to your Charger's engine if installed incorrectly.

Items you will need

  • Automotive tool kit (if performing the upgrades yourself)

 How to Add Horsepower to a 2002 Dodge RAM 1500

Open the driver's side door, and pull the hood release lever, located under the steering wheel. Press the release tab under the grille, and open the hood.

Place a step ladder near the vehicle to allow you to access the engine easier.

Remove the nut that holds the negative connector onto the battery with a wrench. Remove the connector, and set it aside.

Locate the engine computer by looking on the passengers side firewall. It mounted to the firewall. There is a large electrical connector hooked to it.

Remove the connector by pressing the release tabs on both sides of the connector, simultaneously, and pull it towards you.

Plug the male end of the Jet performance chip into the computer port.

Plug the stock wiring harness into the Jet computer chip. Confirm that each are secured tightly, by slightly pulling on them.

Reconnect the negative terminal to the battery. Tighten the bolt with a wrench.

Items you will need

  • Step ladder

  • Wrench set

 How to Add Horsepower to a Grand Marquis

Replace the Grand Marquis engine control chip with a performance aftermarket control chip. The engine control chip, or engine control unit, is responsible for managing the electronic fuel injection (EFI) system. Factory engine control chips are fairly restrictive in order to maximize safety and fuel efficiency, especially in non-performance oriented vehicles such as the Grand Marquis. Performance oriented engine control chips will reprogram the functioning of the EFI system for maximum performance, which may decrease fuel economy but will substantially increase horsepower.

Replace the Grand Marquis air intake with a performance cold-air intake. The factory air intake on the Grand Marquis is fairly restrictive in order to keep engine noise and cabin noise minimal. A performance cold-air intake will allow more air to enter the combustible air/fuel mixture inside the engine, which provides more available horsepower.

Replace the Grand Marquis exhaust system with a performance exhaust system. As with the air intake, the Grand Marquis factory exhaust system restricts airflow in order to maintain a quiet cabin, as well as to minimize CO2 emissions. Although installing a performance exhaust system will increase engine noise and emissions, it will also increase available horsepower by allowing the Grand Marquis engine to release hot air and engine pressure more efficiently. Further, many Grand Marquis owners enjoy the louder, more aggressive sound that a performance exhaust system produces. Make sure to consult state regulations before performing this step, as some states prohibit aftermarket exhaust systems.

 How to Add Horsepower to 1985 Harley-Davidson XLH Sportster

Stage One

The most popular starting point for boosting performance is known as a "Stage One" upgrade through Screamin' Eagle, otherwise known as "paying your Harley tax." This includes replacing the stock air cleaner element with a low-resistance air cleaner, removing the stock exhaust and installing a low-restriction exhaust, and replacing the jets in the carburetor with larger ones. It is recommended that you use a low-restriction performance muffler, and avoid using straight-, or drag-pipes, because they have no backpressure and will make it difficult to tune the exhaust. Anti-reversion cones -- also called powercones -- help provide some backpressure and prevent exhaust-gas reversion. Making these changes effectively opens up the engine and allows it to breathe as the factory intended, increasing horsepower and throttle response.


Upgrading the ignition coil to a high-output coil, along with performance spark plug wires, will give a small horsepower boost along with a slight mileage increase by creating better flame-front development and reducing wasted free hydrocarbons exiting the exhaust. Screamin' Eagle offers a performance electronic ignition module that will allow you to tune the power curve and adjust the rev-limiter to maximize performance according to your riding style. Performance points are recommended if you have converted to a points ignition. Use high-performance points with a built in self-lubricator for good ignition performance with less frequent need for points adjustments.

Machine Work

Increasing the swept volume of the engine by boring it to 1100 cc and installing high-compression pistons will increase your horsepower and torque significantly. Mid-grade or premium gasoline will be necessary to prevent preignition or detonation once engine compression exceeds 9.5-to-1. Performance cams are available from Screamin' Eagle and other aftermarket sources, that will enhance your power curve and increase your torque band significantly. Port and polish the intake passages in the heads, and use a five- or seven-face grind on the intake seats.


Tampering with the intake and exhaust, or making any changes to the emissions on the bike, can be a violation of state and local laws. Check for ordinances against sound emissions and exhaust-gas emissions before making modifications to a bike that is intended for road use. Do not take half-measures when modifying the intake and exhaust systems. Changing the pipes or intake without increasing the size of the jets will lead to a dangerous lean-running condition that will cause the engine to run hot and can cause piston damage. Give particular attention to maintenance on other areas of the bike when increasing performance. The performance of the brakes and the condition of the tires become infinitely more important as you increase your capabilities and use these capabilities during maneuvers in traffic.

 How To Add More Horsepower to My Integra

Install a cold air intake. One of the first and most common tricks to getting more power from your Integra is the installation of a colder air intake, such as the one from Greddy. Engines thrive on cold, dense air, so replacing the stock air box with a cone filter and larger intake tubing will give an instant power gain.

Install a larger diameter, more free-flowing exhaust in place of the smaller diameter stock exhaust from the catalytic converter to the end of the exhaust, also known as a "cat-back" exhaust. The faster you can get spent exhaust gases out of the motor, the more potential power you can get out of it.

Install a 4-2-1 header in place of the stock restrictive manifold. Stock manifolds are mass-produced, with rough casting that gets in the way of smooth airflow as well as smaller than optimal exhaust passages. Replacing the stock manifold with a tubular one will allow exhaust gases to exit the motor more quickly and efficiently. (See Resources 1)

Upgrade the stock computer chip with a performance chip like one from Automotive Concepts. (See Resources 2) A performance chip will recalibrate your fuel and spark delivery for more horsepower.

Turbocharge or supercharge your engine. One of the most effective methods of gaining a significant amount of horsepower from your Integra is by installing a turbocharger or a supercharger. Both of these methods force more air to move through your engine faster, increasing power. It should be noted, however, that this is an expensive modification to perform, usually costing at least several thousand dollars, and should be performed by a professional shop with experience working on Acuras.

Items you will need

  • Full shop with specialized tools for automotive work

  • Acura Integra performance catalogues

 How to Add More Horsepower to a 5.7 HEMI

Reduce engine weight by replacing the iron flywheel with a lightweight aluminum flywheel. The weight reduction allows the engine to rev faster; thus, power can be transferred to the rear tires faster. This improves torque and overall horsepower of the HEMI engine.

Change the iron drive shaft with an aluminum drive shaft. In vehicles with less than 900 horsepower, an aluminum drive shaft reduces the amount of horsepower it takes to spin the drive shaft. This increases the amount of horsepower delivered to the rear wheels.

Flash the ECU (electronic control unit) to take advantage of horsepower that is restricted by the manufacturer. The ECU acts as the brain of the HEMI engine, telling the engine how much air, fuel and spark to deliver to the combustion chamber. By flashing the ECU, the engine will run with better efficiency and with more horsepower.

Replace the stock air filter and air intake box with a cold air intake. A cold air intake eliminates the box and collects air from the inner fender well via a large air filter. The air in the fender well is cooler than the air in the stock air box; thus, the air taken into the engine can be cooler. The cooler air and the larger amount of air going into the engine increases the efficiency of combustion. Installing a large-bore throttle body ensures the higher airflow is not restricted before it gets into the engine. This will aid to the increase of horsepower.

Items you will need

  • Aluminum flywheel

  • Aluminum drive shaft

  • ECU flash tuner

  • Cold air intake

  • Large bore throttle body

 How Can I Add More Horsepower to My 1999 Vortec?

Replace the spark plug wires on the engine. Adding performance spark plug wires will lower resistance within the engine and can increase the signal strength to the actual spark plugs themselves, thus resulting in a faster engine.

Change the air filter to a performance piece. The stock air filter used by General Motors is not conducive to a performance engine and will not allow as much cool air into the engine as an aftermarket part would. Increasing cool air flow to the engine will allow the vehicle to move faster while on the road.

Switch to synthetic oil. Synthetic oil provides the best protection possible for the engine and eliminates friction that is associated with normal motor oil. It also lubricates the engine better while it is in motion, thus allowing it to move faster.

 How to Add More Horsepower to Your Camaro

Upgrade the ignition system. Most Camaro engines, particularly if they are modified, will benefit from a better ignition system. The ignition system determines how much spark the engine is getting, and the more spark the better, especially if the engine is modified to get more air and fuel as well. An electronic ignition replaces the points on older Camaros with an optical trigger and is simple to install in the distributor. There are also more expensive electronic ignitions and electronic distributors.

Install a performance exhaust. This is Tuning 101 when it comes to almost all Camaros. Stock exhausts are smaller than optimal in diameter and stock mufflers are designed primarily for noise reduction and not performance. A larger diameter exhaust will get spent exhaust gasses out of the motor more efficiently and allow it to make more power. Plus, your Camaro will sound the way it was intended to. An exhaust should be installed by a professional who is familiar with the tools and techniques of making and or installing exhausts.

Replace the manifolds with headers. The manifolds are bolted to the Camaro's heads and are the parts that spent exhaust gasses from the engine travel through in their way out of the engine. The better the air can flow out, the more power the engine can potentially make. Stock manifolds are usually cast, which means thicker walls, thinner passages for the air to travel through and rough surfaces, which inhibits airflow. Tubular headers have smooth walls and larger passages, so the motor runs more efficiently and can make more power. Remove the manifolds from the heads and then install the headers in their place.

Install a cold air intake. This is applicable to newer Camaros that utilize fuel injection. The cold air intake consists of large diameter tubing and a large filter. This replaces the air box, which in stock form does not usually flow air to the engine as efficiently as it could. A CAI delivers far more, dense, cold air to the engine and can realize gains of up to 20-hp. To install, remove the air box from where it bolts to the engine bay and where it connects to the intake on the engine. Install the new air intake according to the supplied directions.

Items you will need

  • Socket set and ratchet

  • Specialty automotive tools

 How to Add Horsepower to the 350Z

Increase airflow into the engine. The amount of horsepower an engine produces is directly related to the amount of airflow allowed into and out of the engine, as the air mixes with the fuel. There are several performance upgrades that enhance the flow of air into the 350Z engine. The simplest and most inexpensive is to replace the factory cold-air intake with a performance aftermarket intake. For those looking for larger gains in horsepower, there are supercharger and turbocharger kits available for the 350Z that will provide a massive boost in power.

Increase airflow out of the engine. The rate at which air leaves the engine is nearly as important as the rate at which air enters the engine when considering the overall horsepower of a vehicle. Replacing the stock exhaust, headers and mufflers of the 350Z with wider, more free-flowing aftermarket parts will increase the overall horsepower of the vehicle and also give it a louder, more aggressive sound.

Reduce the weight of the engine. Horsepower is also directly related to the speed at which an engine revs, and lighter engines can rev more quickly. Many parts of the 350Z engine, such as the pistons, can be replaced with aftermarket parts made of lightweight materials which reduce the overall weight of the engine, in turn increasing rev speed and overall horsepower.

Items you will need

  • Automotive toolkit

 How to Add More Horsepower to My Truck

Purchase and install a performance aftermarket cold-air intake system to replace the stock air intake system. Cold-air intake systems are a popular aftermarket modification for all vehicles due to their relatively low cost and the fact that they can be installed at home by an individual with the proper tools and some general automotive experience. Cold-air intake systems increase horsepower by allowing more air to flow into the engine and cooling this air more efficiently. Note that performance cold-air intake systems can result in a moderate increase in engine noise, but on most trucks it will barely be noticeable.

Purchase and install a performance aftermarket exhaust system to replace the stock exhaust system. Exhaust systems are an excellent counterpoint to a cold-air intake system because they allow hot air to exit the engine more efficiently, which allows the engine to maintain an ideal operating temperature even under demanding conditions. This provides an overall boost to horsepower and also gives the engine a louder, more aggressive sound. Note that many aftermarket exhaust systems will drastically increase engine noise and CO2 emissions. It is recommended that you check state regulations on emissions and aftermarket modifications before performing this step.

Purchase and install a forced-air induction kit such as a supercharger or turbocharger kit. Forced-air induction kits are not available for all trucks, but they are available for most newer trucks and some older models, particularly full-sized trucks. However, if there is a forced-air induction kit available for your truck it will provide the greatest horsepower boost of any single performance aftermarket modification you can make. Forced-air induction kits stuff massive amounts of air into the engine, which provides a dramatic increase in power and torque. Some forced-air induction kits can provide a power boost of over 100 horsepower.

Items you will need

  • Automotive tool kit (if performing any of these upgrades yourself)

 How to Add Horsepower to Your Car

Cold air intake. Cold air is more dense than hot air. Therefore you get more air into your engine. A cold air intake takes the intake out of your engine. After your engine has been running for a while it gets hot, very hot, and when you take it out of the engine you get more air. This also adds to your gas mileage.

Supercharger, or Turbocharger. Both a Supercharger and a Turbocharger do the same thing, only in a different way. They both force air into the combustion chamber above atmospheric pressure. The supercharger is powered either mechanically by belt or chain drive from the engine's crankshaft. A turbocharger is powered by the mass-flow of exhaust gases driving a turbine this causes a lag where you get little to no boost while your waiting for the exhaust to exit the engine. Both of these can have horsepower increases from 50-100%. But when you are getting boosts past 10psi you are probably going to have to add an intercooler and use higher grade fuel. And you will want to enforce your engine with stronger parts.

New spark plugs. Next time you get a tune up, see if you can get some performance spark plugs to put in your car. Some platinum or iridium spark plugs will light all the fuel in your car faster and more efficiently so that you have more horse power.

Aftermarket cat-back exhaust. Reduces back pressure of the exhaust in your car increasing horsepower and improving fuel efficiency. If you do not want your car to sound a lot louder then do not go with glasspack exhaust or anything like that.

Aftermarket headers. This also has to do with reducing the back pressure of the exhaust. If you already have a cold air intake and an aftermarket cat-back exhaust system then you will feel the power this gives you.

Performance tires. You can have all the power you want coming out of you engine. But if you don't have any grip from your tires then your not going to feel the power.

New chip. Watch out this is where a lot of people get scammed. Engines are having more and more to do with electronics. Your stock chip in your car is made for the average driver and it isn't using the right fuel to air ratio. This will show best results when combined with a cold air intake.

Items you will need

  • Money

  • Time

  • Patience

 How to Add Horsepower to a GMC Sierra


Install a new computer chip. This will change the engine's programming and will free up more horsepower. This is a quick way to improve the vehicle's performance.

Install an aftermarket exhaust system. This is usually comprised of a larger tail pipe and header. As a result the exhaust will exit the engine faster and allow for improved combustion and energy production.

Install a cold air intake system. This will allow cooler air to enter the engine and react with fuel. Cooler air is more dense and as a result has a larger concentration of oxygen. As a result there will be increased combustion and power generation.

Install a performance tuner. This is a device that changes the ratio of air and fuel mixture in the engine. As a result combustion rates will improve and horesepower gains can be seen.

 How to Add Horsepower to Your BMW X5

Install a performance cold-air intake system. Cold-air intake systems draw in air from outside of the engine bay, cool the air then route it into the engine. Factory-installed cold-air intake systems tend to be relatively restrictive in order to minimize engine noise. Performance cold-air intake systems suck in much more air and cool the air more effectively, which lowers the overall temperature of the X5 engine. This, in turn, provides an increase in horsepower at the cost of a slight increase in engine noise. Cold-air intake systems are fairly inexpensive and easy to install for individuals who have some experience with automotive upgrades or repairs.

Upgrade the BMW X5's exhaust system to a performance type. Exhaust systems blow warm air out of the engine bay and back into the environment to maintain a cooler engine temperature. As with cold-air intake systems, factory exhaust systems restrict airflow in order to lower engine noise as well as CO2 emissions. Aftermarket exhaust systems provide superior airflow out of the engine bay, which reduces engine temperature and increases horsepower. They also increase engine noise and CO2 emissions, and many states have regulations regarding which, if any, exhaust systems can be installed. Consult your state regulations before replacing your X5's exhaust system.

Install a performance computer chip. Most cars made within the last 20 years, including every year and model of BMW X5, use an on-board computer to manage and regulate the function and performance of the engine. By default these computers instruct the engine to run fairly conservatively in order to minimize wear and tear and maximize fuel economy, but this also reduces performance. Performance chips reprogram your vehicle's on-board computer for maximum performance, which may reduce fuel economy and increase stress on various internal components, but provides a substantial boost to horsepower.

Items you will need

  • Automotive tool kit

 How to Add Horsepower to a C6 Corvette

Add an aftermarket exhaust system to replace the stock Corvette exhaust system. An aftermarket exhaust system will allow air to flow more freely as it is exiting the engine bay, which adds horsepower to the Corvette engine. Note that this will also change the exhaust note of the Corvette, typically to a louder and more aggressive sound. While many Corvette owners find this desirable, be aware that it will increase cabin engine noise.

Replace the Chevrolet factory cold-air induction system with a performance aftermarket system. Performance cold-air intake systems allow more air to flow into the engine and also cool the air more efficiently. This lowers the temperature of the engine and increases horsepower.

Tune your Corvette using a flash tuner. A flash tuner modifies the computer that controls the operation of your Corvette's engine. This can provide a minor horsepower boost even if you have not installed other performance modifications on your Corvette. More important, tuning allows your Corvette to take full advantage of any aftermarket upgrades you have installed, maximizing the horsepower gains you receive from installing other components. You should re-tune your Corvette's engine whenever you add a new performance modifications.

Items you will need

  • Automotive tool kit (if performing these modifications yourself)

 How to Add Horsepower to 6.0 Ford Diesel Trucks

Replace the stock air box with a cold air intake. This will allow for a denser air intake charge to enter the engine and will easily increase the horsepower and torque of the engine.

Replace the stock exhaust with an aftermarket one. The stock exhaust is small in diameter and is very restrictive. Aftermarket exhausts are bigger in diameter and allow more exhaust to flow out of the engine, which will ultimately allow the turbo to spin at a higher velocity to increase power.

Flash the engine control unit to so that it increases turbo boost pressure and adjusts timing and fuel injection. This is very simple to do and is quick. Simply purchase a "tuner" from an aftermarket supplier and hook it up to your OBD diagnostic port and go through the commands on the tuner. You can select a "performance" mode and also revert back to stock mode when you want to conserve fuel.

Upgrade the turbo when the previous upgrades still haven't done it for you. An upgraded turbo will allow for more air to enter the motor, which will increase horsepower and torque. Upgrading the turbocharger is a bit more involved in terms of installation but is manageable with some knowledge of automotive systems.

Items you will need

  • Air Intake

  • Exhaust system

  • Chip or tuner

  • Upgraded turbocharger

About the Author

This article was written by the It Still Runs team, copy edited and fact checked through a multi-point auditing system, in efforts to ensure our readers only receive the best information. To submit your questions or ideas, or to simply learn more about It Still Runs, contact us.