How To Increase Horsepower: 20+ Methods

The need for speed is something countless car owners and enthusiasts are obsessed with. Even those who own already fast cars try to squeeze every bit of performance out of them. From mild to wild, there are a variety of ways to add some extra power to your vehicle. Learn 20+ methods on how to increase horsepower, including highly effective but expensive methods as well as easy and affordable fixes. 

Fun Fact: The Origin of “Horsepower” 

Horsepower is a measurement of the rate at which a work is done. Where did the phrase horsepower come from? Exactly what the word suggests: from horses, and a man named James Watt, who used to observe mill horses walking in circles all day, powering the mills.  

How the phrase originated was when James Watt invented a steam engine that he claimed would be at least 200 times more powerful than the mill the horses, but it was difficult for him to explain to the millers how powerful the steam engine is in comparison to their horses. So he developed a formula for measuring workload, based on the estimation that a mill horse would pull/push the mill shafts in a 24-foot circle with a force of 180 pounds for 144 times in an hour.  

He then did more math to prove that such workload means that a mill horse could push 32,572 lbs (rounded up to 33,000 lbs) with a horizontal distance of one foot in one minute. This is equated as the power of one horse. 

Horsepower thus measures the power that a horse gives when pulling, or more specifically the power needed to raise 550 pounds in one second with a vertical distance of one foot, or the power needed to move 33,000 pounds in one minute with a horizontal distance of one foot.

Things to Consider When Trying To Boost Horsepower

A major concern for many car owners is how aftermarket modifications affect a vehicle’s warranty. It’s always best to discuss with your dealership how installing aftermarket performance parts may affect your warranty.

This is because car manufacturers are not thrilled with owners trying to re-engineer their vehicles, which costs a lot of time and money and brainpower to optimize aesthetics, performance and safety. In some cases, certain automakers do allow the installation of in-house performance parts when installed by an authorized dealer. 

Another aspect you must consider before having your car tuned up with aftermarket performance parts is emissions regulations. Many countries and states, such as California in the US, require certain aftermarket performance parts to comply with emissions standards for the affected vehicle to be deemed street legal. 

While you can choose to install non-compliant parts, it may compromise your ability to pass emissions testing. Therefore, you should spend some time checking your local emissions laws before deciding on certain engine performance parts.

Finally, you need to be aware of the fact that your vehicle, when it came out of the factory, was already optimized as a whole, and any changes to any part can render other components less efficient. While modifications like an exhaust or an intake may have minimal impact on the vehicle’s overall performance and safety, more hard-core modifications like a supercharger can drastically alter the vehicle’s fuel economy or long-term reliability.

Therefore, take into account any compromises you might be making when making modifications to achieve better horsepower. Also be prepared that when you opt for a drastic upgrade like a supercharger, you will most likely have to spend a lot of money to get many other parts upgraded too as a full kit so as not to sacrifice your car’s overall efficiency, drivability and safety. 

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How To Increase Horsepower: Effective But Expensive Methods

We’ll start off our list of 15+ methods on how to increase horsepower with the most effective upgrades with immediate and noticeable power gains. 

If your vehicle’s engine is naturally aspirated, forced induction will provide some hefty hp increase. One of the most effective ways to increase hp is forced induction. Forced induction can come in the form of a turbocharger or a supercharger. These upgrades are popular with hard-core performance enthusiasts and street racers, and you might have seen one in one of the Fast and Furious movies.

This is one of the most expensive engine enhancement modifications, so feel free to skip it if you have a budget. But if you can afford it, then go blindly with this mod as a good supercharger will boost your horsepower up to 625+ and torque up to 525+ lb-ft. Such numbers are surely mind blowing considering that you’re getting just one set of upgrades.

Before considering whether this mod is worth it, you should grasp the basics of  superchargers and turbochargers. 

To help the engine generate more power, two things are needed: more air and more fuel sucked into the engine’s combustion chamber. It should be noted that a specific ratio is required for the engine to work: 14 parts air to one part fuel. 

The air pumped into the combustion chamber is regular air at atmospheric pressure. The compressing happens later with the working of the piston, which moves up to compress the air and fuel mixture, thereby creating a “vacuum”.

The supercharger/turbocharger increases air intake simply by compressing air at above atmospheric pressure before pumping into the combustion chamber. With more air intake, more fuel can be pumped into the combustion chamber for the engine to combust to create more energy.

As mentioned above, an important reminder: since adding forced induction puts more strain on your  engine and drivetrain, you may need supplement modifications to support such an extra stress, such as a more heavy duty clutch or cooling system. This will vary by each vehicle model, so you should consult a professional on what should be done.

Supercharger

Forced induction systems compress the air flowing into your engine. By “forcing” in more air, the engine can burn extra fuel to produce more power. Later on, you will come across a few more aftermarket parts than also boosts engine power by the same general mechanism. 

A supercharger can add an average of 46% to 50% more horsepower, and 31% more torque, a car’s rotational or twisting power (as opposed to linear power like a push or a pull). 

While trying to boost horsepower, remember that this measure is tied to torque mathematically. Torque is a crucial measure of an engine’s power, as it represents the load an engine can handle to generate a certain amount of power to rotate the engine on its axis. Horsepower equals torque multiplied by RPM (evolutions per minute), divided by a constant. Because there is generally a limit on how fast you can spin an engine, having higher torque allows for greater horsepower at lower rpms.

Compared to their cousin the turbocharger below, superchargers are easier to install than and give you more instantaneous power surge when you step on the gas. This is because they get power from a belt connecting directly to the engine on the way in, thus as the engine runs, a supercharger gets to work immediately. 

This belt-driven feature makes them most effective on six-cylinder engines, as opposed to four-cylinder engines. They also don’t require an intercooler as a must-have supplement modification, so you will less likely encounter overheating issues or break down.   

Turbocharger

A turbocharger “recycles” energy from the exhaust stream to power themselves, thus compared to superchargers, they are extremely efficient. However, due to the nature of this mechanism, there will be a delay or “turbo lag” before you can notice a horsepower boost. This lag while it builds boost means no instantaneous response like with a supercharger.

With a turbocharger, you’re generally looking at a 25% increase in horsepower, even though the peak Hp can be higher than the supercharger in some cases. 

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Nitrous

Essentially a portable supercharger/turbocharger, this upgrade is another badass Fast-and-Furious favorite. It is also expensive, but it is deemed more favourable than a supercharger/turbocharger by many thanks to its portability. This might be the most appealing feature, even the deal breaker, since you can take the kit from car to car without losing your sizable investment.   

Being another mod that deals with the air your engine “breathes” in, Nitrous is like a can of “air-maker”. It essentially creates more air for combustion within the engine, thus generating more power from these combustions.   

Do note that this engine enhancement is illegal in many countries and states, so do check your local regulations carefully before making the investment, and quite a big investment at that. A Nitrous kit can cost you from $900 to over $3,000.  On the plus side though, they can be used as support to a turbocharger or supercharger to reduce turbo lag and increase the final boost of horsepower. 

Performance Chips/ Aftermarket Software

For almost any factory turbo car, a performance chip or tuner is by far the best bang for your buck when it comes to getting more power and efficiency out of your vehicle. Pair one of these performance chips with other modifications in this list, and your beastly machine will be breathing fire in no time.

In addition to horsepower, these tuners can also enhance throttle response, fuel economy, towing power, gear ratio, air intake index and more. Some chips are designed chiefly for unleashing the hidden power from the engine, which would require more fuel, while some are designed to increase fuel mileage of your vehicle by optimising other parameters.

One purpose of factory-installed chips, or the Engine Control Unit (tECU), is to ensure that everything runs in accordance with specifications so as to comply with emissions regulations. At the factory, the ECU is often tuned conservatively to allow for lower grade fuels and to minimize the stress on internal engine components. You can alter these specifications with the goal of optimizing horsepower by installing a performance chip. 

A performance chip is an aftermarket software, also referred to as a “flash”, and to install a performance chip is also called “to reflash your car’s computer. It is designed to take full advantage of your engine by adjusting the ignition timing to smooth out power delivery, which would often require premium gasoline to do the job. 

In addition, they also let you easily alter the fuel-to-air ratio and the turbo boost, yielding an instant horsepower increase without you having to go into the engine compartment and get your hands dirty. All it involves is connecting the chip to the OBD-II port to access the information. 

These tiny kits allow for more horsepower, torque, and even better gas mileage. Depending on the engine, you can see some pretty hefty power gains. This is a modification often done in conjunction with a turbocharger or supercharger, as the aftermarket software also allows the turbocharger to produce more boost pressure, which equates to more engine power.

One important reminder is if you choose to install a performance chip, be sure to purchase from a reputable tuner, as engines are very sensitive to changes. Also note that software upgrades are often available in stages, where in each stage, you’ll need to select the upgrades that best suit your engine’s current configuration.

How To Increase Horsepower: Air-Related Methods  

You might have noticed a recurring theme at this point: An effective way to increase horsepower has a lot to deal with air, and specifically, as you will see later on, with both the air your engine “breathes in” and the air it “exhales” as exhaust. 

In essence, your car engine is one big air pump with a series of deliberate combustions that push as much air in and out of it as possible to optimal power. The bottom line is the faster, the more efficient and also the cleaner your car can breath in and out, the more potential you have for horsepower gains. 

In other words, if you want to increase horsepower, essentially you’ll have to find different ways to supply air in a greater volume through your engine, and cleaner air at that, as well as helping your engine to breath out more smoothly. More air means the engine will burn more fuel, and burning more of the air-fuel mixture means more power generated from combustions. 

The engine enhancement mods below will deal with air intake and exhaust to achieve this general goal.

Velocity Stack

A velocity stack, also called intake trumpets, is a trumpet-shaped aftermarket part that is fitted to the air entry of an engine’s intake system, the carburetor or fuel injector to improve airflow. 

The velocity stacks improve airflow into the engine’s combustion chamber in three ways. 

Firstly, the trumpet shape smooths the flow of air into the intake, allowing the most air possible to flow through the given volume of the intake. Second, they smooth out the flow of air that rushes into your intake, and smoother air flow means more air flowing through at any given time. Lastly, these little devices clean up the air and prevent the non-plenum kind of carburetors from barfing fuel and catching on fire.

While this upgrade is simple and affordable, a properly tuned intake velocity stack would only add around 3% horsepower gain on average as a standalone installation, so it is usually done with other engine enhancements.

Why are these intake trumpets installed to the carburetor or fuel injector too? Quick recap. A carburetor used to be the most common and basic way that engines in older cars got fuel, before the age of fuel injectors, or fuel pumps. It mixes air and fuel together before it’s sucked into your engine. 

Performance Air Filter and Intake

Another quick, cheap and easy way to throw a few more horsepower at your engine, also used as a support mod, is to swap out your air-filter for a high performance one. It allows your engine to breath in cleaner air, smoothes air flow and thus kicks in a small amount of additional power.  

Keep in mind that you need to check your state’s regulations as not all performance air filters are legal in all countries and states.

High-Performance Cold Air Intake 

As mentioned above, the colder the air is, the denser it is, which means the more air in a given volume. For this same reason, you’ll notice a balloon may appear to deflate when you take it outside in the cold, or your car tires will appear to lose air in the winter (The opposite is true, which is why it’s recommended not to overinflate tires in hot weather, as they might burst from the hot, less dense air). 

In other words, if you can somehow make the air going into your car’s engine denser, there will be more air molecules present to mix with fuel to be ignited for power generation.  

A high performance cold air intake does exactly this.  Cold air intakes draw colder air into the engine from outside the vehicle.  High performance cold air intakes have special filters that reduce resistance and unwanted turbulence that would otherwise inhibit steady airflow to the engine. In addition to smoothing out airflow, these filters also increase the surface area in which the air is pulled through into the engine, sometimes as much as three times larger than your standard factory air intakes. 

Intercooler Kit

As above, an intercooler kit is often installed to supplement a turbocharger. Similar to a high performance cold air intake, installing an intercooler kit will also make your engine breath in more air. It does this with the same mechanism: cooling the air supplied to the engine to condense it. 

An intercooler, or “charge-air cooler”, is an air-to-air or air-to-liquid heat exchange device used on turbocharged and supercharged internal combustion engines to improve their volumetric efficiency by increasing intake air-charge density through isochoric cooling.

In layman terms, a heat exchanger is a device designed to efficiently transfer or “exchange” heat from one matter to another. When a fluid is used to transfer heat, the fluid could be a liquid, such as water or oil, or could be moving air.

Basically, an intercooler uses air from the atmosphere, flowing it over and around a lot of finned tubes to remove heat from the intake air charge which means it reduce the temperature of the air that has been pressurized by the supercharger/turbocharger that is going through the intake tubes.

When you use air-to-air heat exchanger, cooler air will be directed towards the tubes that will maximise the cooling effect and ultimately enhance the performance of your vehicle.

Keep Your Filters Clean

As above, the cleaner your engine can breath, the better for its performance. Keeping your air and fuel filters clean is a simple maintenance job that will ensure your engine gets the maximum airflow without turbulence for optimal power output.

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Exhaust Headers, or Performance Exhaust Manifolds

Improving engine performance and horsepower is all about airflow, and what’s important is it’s not just about the air coming into the engine. The air going out also matters. One way to improve this mechanism is installing an exhaust header, which is basically aftermarket upgrade exhaust manifolds for performance applications. 

Factory-installed exhaust manifolds are designed to meet emissions requirements, not provide optimum horsepower. Replacing these parts allows air to move more quickly through the exhaust system. 

Headers are intended to solve the engine efficiency and power setbacks of the exhaust manifold. In short, exhaust manifolds create back pressure, which lowers the engine’s overall performance. 

Let’s dive into more detail so you will understand how to increase horsepower with exhaust headers. Exhaust manifolds channel exhaust away from the cylinder head to the exhaust pipe and eventually out the back of the vehicle via the exhaust pipe. Exhaust manifolds are typically made from cast iron in a block-like configuration.

Also the prized material for expensive cookware, cast iron is very sturdy and long living. Importantly, because cast iron is thick and maintains heat well, the exhaust manifold can prevent heat from leaking to other nearby parts, which would wear them out prematurely. This feature is also good for controlling emissions.

The iron casting makes the interior of the wall of the exhaust manifold rough, which can slow the flow of air and introduce turbulence. In addition, the thick walls mean there is a small space for exhaust gases to pass through. 

This slow flow of exhaust gases creates a problem called back pressure, which keeps the exhaust from being cleared as efficiently as possible. Because exhaust must go out to allow fresh fuel and air to be injected into the engine’s chamber for a new combustion, back pressure ultimately reduces the engine’s efficiency and power output.

To improve efficiency, exhaust headers use an individual steel tube for each cylinder. These tubes all connect to a collector pipe. The tubes are smooth and equal in length, and this ensures that the gases from each cylinder reach the collector separately, avoiding back pressure.

Long-tube headers give you more horsepower at midrange and top RPMs, while shorter headers deliver improvements at lower RPMs.

High Performance Exhaust System

As said, the air coming out of your engine is also important, not just the air that comes in. Installing a high performance, free flowing exhaust system with larger diameter piping will allow your car to expel exhaust quicker. 

Just like us, the faster the car can exhale carbon monoxide, the quicker it can inhale fresh oxygen to prepare for the next combustion. This means an overall increase in the amount and efficiency of airflow, thus contributing to the boost in horsepower.

With all the sound deadening, NVH improvements, and quality materials these days, it’s getting harder and harder to hear these trucks because their engines are so quiet and smooth. That’s great if you’re looking for something unobtrusive, but some of us want to hear the power we’re putting down for an enhanced driving experience. In fact, many car owners prefer an aggressive and throaty high performance sound that is fitting of a high performance fire-breathing beast. 

From loud and intimidating to subtle and rumbling, you’ve got a range of performance exhaust choices to choose from. For your information, side exit with dual chrome tips exhaust systems are in as they not only produce really badass sound but also look extra sleek.

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Catalytic Converter

In case if you’re not aware of Catalytic Converter, It is an exhaust emission control device that reduces toxic gases and pollutants in exhaust gas from an internal combustion engine into less-toxic pollutants by catalyzing a redox reaction. It is built into the vehicle’s exhaust system, and directly affects the performance of the engine. 

In other words, a catalytic converter is a device that uses a catalyst to convert three harmful compounds in vehicle exhaust into harmless compounds. And, by neutralizing hazardous compounds in your exhaust such as carbon monoxide, it will ultimately be increasing the gas mileage and performance.

How To Increase Horsepower: Proper-Maintenance Methods

If you are not willing to spend on big investments on superchargers or turbochargers, the good news is there are many other more affordable ways to boost horsepower. They are not fancy upgrades, but proper maintenance here and there to keep your engine always in tip top shape, thus maximizing its power and efficiency. The littlest things add up, so do not underestimate the total impact of these maintenance. 

Use the Right Gas 

The very first thing, which is the easiest and most affordable, is to make sure you are buying the right food for your baby. If you spent the money on a high performance car, don’t ruin it by putting low-octane gas in it. High performance cars always require the highest grade fuel.

The recommended gasoline for most cars is regular octane, which has the lowest octane rating of 87. Midgrade or the middle range has a rating of 89 to 90. Premium gas has the highest rating of 91–94. The manual of high performance gas would specify which grade of gas you should buy for your expensive four-wheeled investment.

For instance, if the specified octane rating is 91 and you buy a lower grade gas, you could damage the engine and may void your vehicle warranty. That said, using a higher octane gasoline than your owner’s manual recommends offers absolutely no benefit. 

Low-octane gas will cause two things. For one, in older cars it adversely affects your engine’s efficiency in generating combustions, thus directly eats up power output. Secondly, in newer cars,  the vehicle will electronically adjust to the mediocre gas by combusting at a lower rate, thus killing horsepower.

Shed Unnecessary Weight

Keeping your car neat and light is key to adding a bit of extra horsepower, and is beneficial to your vehicle in the long run as it is not made to bear unnecessary weight. This is a simple quick fix that many drivers are not aware of or underestimate. 

Clean out your trunk regularly to remove things you do not need to bring along all the time, which is, almost everything. If you are single with no family or partner and speed is the only love of your life, you should go more hardcore than just cleaning out your trunk. 

What you can remove includes spare tires, air conditioners, speakers, car jacks, even the back seats. If you remove your entire air conditioner, plus a companion of average build, you’re looking at up to 250 lb weight reduction, which is tremendous if we’re talking about how to increase horsepower. 

Many speed enthusiasts and street racers go so far as to replace parts of their car with the lightweight but durable fiberglass or carbon fiber.  

Proper Lubrication

Another big rule of thumb is anything that creates friction in your car’s engine, or anything mechanical, reduces performance.  This is why it is important to change all of your car’s fluids on schedule to ensure it is always in tip top shape. The better you lubricate your engine parts with a good motor oil, the more power output you can add to your engine.

Better yet, you can opt for synthetic lubricant. Synthetic lubricants create better lubrication between moving parts than conventional oils. They don’t break down in high-heat, high-stress situations, which is why you see them used a lot in racing. Less friction and the resulting overheating means they help engines live longer and work more efficiently. 

They also offer excellent cold weather performance and extreme temperature protection. Certain brands of synthetic oil are specifically engineered to be more robust in terms of low-temperature pumpability, high-temperature stability and protection against deposits.

Spark Plugs Replacement

Spark plugs are the tiny component located inside the cylinder heads and ignite the air and fuel mixture to create a combustion. Needless to say, without efficient and properly maintained spark plugs, there will be no combustion and no power for your engine.

They are highly prone to wear and tear. Over time, spark plugs get dirty, corrode and eventually wear out. Even if they do not exactly die on you, they would not be nearly as efficient as when they were new. 

So an easy maintenance job that you should not underestimate in maximizing horsepower is to inspect and change your spark plugs regularly to make sure your engine is working as efficiently as possible. You can also opt for platinum tip spark plugs, which are much more durable and corrosion-resistant than regular ones.

Ignition Components Replacement

In addition to spark plugs, other ignition components must be treated with the same care for the same reason. These include coils and ignition wires. 

It must be stressed that your engine requires the utmost precision of every component for optimal power output and efficiency. Even the tiniest deviation in one single part can spell big trouble. For instance, a misfire, inaccurate ignition timing or a not strong and hot enough spark means loss of power, wasted fuel and increased tailpipe emissions. 

Therefore, to ensure optimal ignition, that is correct timing and strong, hot spark, buy high performance ignition parts and properly care for them. Again, this does make a difference in power no matter how small. The lesson here is that small gains here and there will add up to a large total gain in horsepower, given that you know what you’re doing.

Because ignition systems have been improved to demand less maintenance in the past 2 decades, most car owners don’t check them until they get a misfire and a “Check Engine” light. Make a schedule for inspection, and when it’s time to replace ignition components, opt for the best high-performance ignition coils and ignition wires you can find, on top of platinum tip spark plugs.

One note here is that ignition timing is also a power dynamic you should play with carefully because if things go wrong, it can damage your engine instead. With conventional distributor ignition systems, for the first adjustment, set total timing at 2500 RPM at 32 degrees Before Top-Dead Center (BTDC) with a road test or dyno pull. Then, move timing one degree at a time up to 36 degrees and so on along with road test or dyno pull. Never take total timing beyond 36 degrees BTDC.

Although some tuners still go beyond 36 degrees, this would impose risks due to detonation. If you have a sudden lean condition coupled with early timing, you can have engine failure in a nanosecond at wide-open throttle. 

Playing with ignition timing with electronic engine control is something not recommended as a DIY project. This calls for a professional who knows how to dial in both ignition and fuel maps without risking permanent engine damage.

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How To Increase Horsepower: Performance Engine ReBuild

If you’re dead set on squeezing the optimal horsepower from your existing engine, in addition to getting a full turbocharger/supercharger upgrade, you’ll need to deep dive into a performance engine rebuild. This requires rebuilding the engine with performance parts such as performance cylinder heads, pistons, and a stroker crankshaft to name a few. 

This is a large DIY project that requires disassembling an entire engine, plus it requires knowing the right assemble of upgrades that best go together for optimal results and minimal compromises. Therefore, this is best left to an experienced engine builder, and not just any mechanic.

Larger Throttle Body and Injectors

The throttle body is the part of the air intake system that controls the amount of air flowing into the engine. A high-performance throttle body will deliver more horsepower. Due to the wider diameter of the tubes, activating the throttle body allows more air to pass through the manifold into the engine, increasing its performance.

Depending on what type of engine you have, you can gain as much as 15 to 25 more horsepower and comparable torque. In addition to increasing overall horsepower, larger throttle bodies can also improve acceleration performance. 

There is a limit though as to how large you can go for. Get a throttle body too large and you can lose power. This is because the bigger the size, the higher the RPM needed for a kick of power. If your new throttle body is too big, your vehicle will feel tired at lower RPMs.

In addition, not every engine is well suited for a larger throttle body upgrade, so make sure you consult with a professional as to what tunes can be done on your engine. Also, it’s safer still to browse the internet and learn what others with the same engine are doing that works or not. 

Also remember that throttle body and injector size are proportional, so a larger throttle requires higher-flow fuel injectors. As a supplement upgrade, you must also take your car to a reputable dyno tuner to make adjustments to fuel and spark curves, which fine-tunes and supports your throttle body and fuel injector upgrade.

Increase Compression

A crucial process for an engine’s combustion is that the air and fuel mixture is compressed into a small volume within the area of the engine’s cylinder. 

Increasing compression is one of the most productive ways to increase horsepower. A high compression ratio is desirable because it allows an engine to extract more mechanical energy from a given mass of air–fuel mixture due to its higher thermal efficiency.

Increased compression also means more torque. Increase in compression ratio induces greater turning effect on the cylinder crank. That means that the engine is giving more push on the piston, and more torque is generated.

How much horsepower can this method add, you ask? The generally accepted gauge for adding compression is that one full point of compression can add between 3 to 4 percent power. So, if an engine is making 50 horsepower and we add a full point of compression (from 11 to 12:1 for example), this could potentially push the power to 51.5 horsepower.

But be careful about how you raise compression. Higher compression engines tend to blow head gaskets a little quicker and wear out faster, so a few things must be done so that the engine can handle this upgrade. 

Compression and camshaft selection go hand in hand to avoid engine damage because cam selection also affects cylinder pressure or working compression. For instance, since the bigger cam closes the intake later, the piston is higher, and the effective or dynamic compression will drop compared to a shorter cam. 

You should go to an experienced engine builder to get the best advice on the optimal degree of compression and cam selection. Another factor to fine-tune is to watch fuel and spark curves while you are increasing compression. 

The compression ratio refers to the degree to which the fuel mixture is compressed before ignition. A compression ratio of six means that the mixture is compressed to one-sixth its original volume by the action of the piston in the cylinder.

Too high a compression ratio is not desired in many cases. A higher compression ratio means more heat inside the engine. With this engine enhancement, you must get fuel with a higher octane rating which can withstand more heat. High octane, smog-legal unleaded fuel is available in five-gallon cans if you have the budget for it.

Or else, at a compression ratio beyond 10.0:1, your engine is more prone to premature ignition or pre-ignition, also known as detonation or engine knock. Premature ignition  alters the piston’s stroke and can lead to serious engine damage.

Performance Camshaft

There are valves that let the air/fuel mixture into the engine’s chamber and the exhaust out. The camshaft uses cams, or lobes, that push against these valves to open them as the camshaft rotates and springs on the valves to close them. 

Needless to say, this directly has a great impact on an engine’s power and efficiency at different speeds. Specifically, there is a direct relationship between the shape of the cam lobes and the way the engine performs at different speeds. Let’s remember this for now and not diving into too complicated mechanical explanations.

In simple words, a performance camshaft has a special lobe profile for optimal engine efficiency. A performance camshaft usually has a higher lift on the lobe, which increases the length of the valve stroke. This allows for more air to enter through the inlet valves, thus increasing the engine’s power output.

Installing a performance camshaft can increase the duration and timing of the value openings during the engine stroke, ultimately increasing horsepower and improving acceleration performance.  

The downside to this is you’ll likely idle slightly rougher with a performance cam, but for some gearheads, getting a throaty rumble is actually desirable. The other is cot: you can count on spending $900 to $3,000 on a cam install.

One thing to note is you should consult a professional for this upgrade, since to get the best performance for your application, the camshaft profile must match your head and valve train components. In addition, choosing the right profile of camshafts is critical. 

This is because camshafts use a combination of separation angles, lift, duration and lobe acceleration/ramp rates to create what is called a cam profile, and the profile you choose determines where your maximum horsepower and torque will occur. 

Cylinder Head Right-Sizing

The cylinder head is the main component that flows air-fuel mixture in and exhaust gases out. Installing the larger cylinder head can contribute to power output and support other upgrades you’re planning to do.

When it comes to engine rebuild, most of the times upgrades go hand in hand. With the performance camshaft installation, you should also get a cylinder head of the right size that works well with the cam to achieve good overlap and nice flow-through momentum.

Before, speed enthusiasts could only get a very selection of limited cylinder head sizes. 

A good cylinder head swap will get you more power if you get the correct size. Again, bigger doesn’t always mean better for max engine power. Also, you don’t need huge valves and monster ports for better torque, which calls for good intake velocity coupled with compatible exhaust scavenging.

To decide which size is optimal, look at valve and port size along with flow numbers, and of course it’s best to get a professional’s advice on this one. 

Dual-plane Manifold

One thing that performance enthusiasts often overlook is trying to get better torque as well instead of just horsepower. On the street, you’d want torque to hand off smoothly to horsepower at wide-open throttle. However, you won’t get this with a single-plane intake manifold that comes factory-installed in your vehicle.

One way to improve torque is installing a performance dual-plane intake manifold. A dual-plane manifold has a split opening in the plenum area directly below the carburetor mounting pad. Each side of the opening feeds four cylinders on a V8 engine. Single-plane manifolds have a single intake opening into the plenum and feed all 8 cylinders directly.

The smaller plenums of a dual plane manifold increase the airflow velocity. They also transmit the induction pulses from the intake valve to the carburetor more efficiently. This improves fuel atomization and metering, especially at low RPM. 

A performance intake manifold also offers better idle quality and great low- to mid-range torque while also allowing an engine to breathe at high RPM. It’s the dual-plane manifold’s long intake runners that give you  greater torque numbers, and high ceilings that deliver more horsepower on top during acceleration.

Again, if you decide to go this route, consider the use of a carburetor spacer to get even more torque.

Or: Engine Swap

If a thorough engine modifications to increase horsepower is not your cup of tea, that is if you don’t want to tear your existing engine apart to modify the internals, then an engine swap may be a more logical route. Swapping in a more powerful motor can be an effective way to increase your vehicle’s horsepower, although this also likely requires a professional in some cases.

Depending on your vehicle, some engine swaps are fairly manageable, while others may require extensive fabrication. If you think you won’t need a professional for this job, It’s always safer to do some research to see how others have performed a similar engine swap.

How To Increase Horsepower: Other Affordable Methods

Fuel Line Right-Sizing

As mentioned above, if you go the engine rebuild route, a lot of parts need right-sizing in order to support other modifications, on top of contributions to horsepower. 

As horsepower increases so does the volume of fuel required to support that power. You’re not going to get optimal horsepower from a fuel line that is too small, just like how you cannot drink fast with a small straw.

High-performance engines need more fuel at any given time. Minimum fuel line size should be 3/8-inch for most performance applications. A general guide is when horsepower rises above 500, you need a 7/16-inch fuel line to support this increase.

Fuel Pump Right-Sizing

Another thing that you need to get the size right is the fuel pump, which delivers fuel from the tank to the engine. The amount of horsepower that your engine has will determine how much fuel flow is required to support that engine and this will determine the optimal fuel pump size.  

Fuel Pumps are sized by flow rate. Flow rate is the amount of fuel a pump can supply in a given period of time. It is usually measured in gallons per hour (gph) or liters per hour (lph). However, note that the gph is affected by the fuel pressure required for your engine. 

A fuel pump will flow at its highest volume when there is no pressure (free flow). As fuel pressure increases, fuel flow decreases. Every pump has a different flow volume at a given pressure.

A good estimator of volume to power is approximately 10 hp per gallon or 2.64 hp per liter.  For example if your pump flows at 55 gph it should be able to support a 500 hp engine.  

Water-Injection Kit

While this modification will not directly boost horsepower on a naturally-aspirated engine, you will see noticeable gains in horsepower when it is coupled with superchargers or turbochargers. 

A water-injection kit can both increase your vehicle’s gas mileage while reducing carbon deposits in the combustion chambers, thus helping to prevent pre-ignition in case you’re using a lower grade gas than what your vehicle should get. 

Upgrade your Wheels

As above, shedding unnecessary weight can contribute to horsepower, albeit we’re not talking huge gains. Swapping for high performance wheels and tires can reduce quite a lot of weight: you can shed about 10 lbs or more per wheel. And they will improve drivability and handling as well, which is desirable at higher speeds.

Sprint Booster for Improved Drivability

If you’re looking to improve drivability without putting any extra tuning mods, then the Sprint Booster is a perfect alternative for you. The best thing about this upgrade is you can easily use it with or without other tuners/programmers due to its ability to work independently from other modifications.

Sprint Booster makes your vehicle feel more powerful because the given pedal input produces greater throttle opening. This is pretty popular among performance enthusiasts and those hardcore truck lovers who love as much customization as their budget allow.

Basically, Sprint Booster modifies the signal between the accelerator pedal module and the ECU. The improved signal encourages the throttle to open more than what the stock signal was providing at a given pedal position. The end result is the idle-to-full-throttle pedal travel is reduced.