So You Want More Horsepower, Huh? Here’s Where to Start

Ford Mustang More Horsepower Flowmaster Exhaust

Well of course you want more power, we all do! But where should you start? Well, there are many ways to spin a tire, so I decided to write up a general guide for squeezing more oomph out of your engine. We already know more is better (duh), but in order to do this right, we need to figure out what we’re doing and why in order to get where we want to go.

So before we get into the parts you need, let’s establish the four basic steps your engine takes to make the power it does:

Suck, Squeeze, Bang, Blow.

Don’t worry, we’re not getting into NSFW territory here or anything, that’s actually how 4-stroke engines work. Check it out:

Suck: The piston travels downwards, intake valves open, pulling in air and a little bit of liquid courage (gasoline or diesel, for our purposes)

Squeeze: Piston travels back upwards with the valves closed, compressing the air/fuel mixture

Bang: A spark (or purely pressure in the case of diesel) ignites the compressed mixture, causing a controlled explosion and pushing the cylinder back down

Blow: The piston travels back up with the exhaust valves open, pushing the burned fuel out, and ready to start the cycle again

Magnaflow Exhaust Pontiac Firebird 400

So with that in mind, you’ll notice that the most common upgrades these days really deal with the first and last step. Car manufacturers really tend to play it on the safe side in these areas for maximum efficiency as well as making sure everything works perfectly in a wide range of possible conditions the engine might need to run in, such as extreme temperatures or at elevation. However, as enthusiasts, we know what we want from our cars, so we’re willing to sacrifice adaptability in those edge cases to work best for what we actually use our stuff for.

With all the different cars, trucks, and SUVs out there, this will have to be a pretty general guide, but the principals translate to most. Let’s get into some popular first upgrades!

Air Intakes

K&N cold air intake

This is pretty much a rite of passage for any car enthusiast. On their own they aren’t going to give you a ton of power, but are the first step in opening up more airflow for the rest of your mods to take advantage of. Oh, and they give your engine a satisfying growl under acceleration. I’ll be honest, I’ve put a CAI (cold air intake) on a few cars for the sound alone. Don’t judge me!

Just like with anything, you can spend just about as little or as much as you want here. Technically the right size tube with a piece of foam stuck on the end should work in theory, but I’m willing to guess you’re reading this guide because you’re looking for something engineered specifically for your vehicle and that will, you know. Actually improve something.

There are a few types of intakes to look for, as well as some example models to check out:

Short Ram Intakes:

HPS Short Ram Intake RedThese are generally the cheapest route, and usually not as effective as a cold air intake, as they generally bring in exclusively hot air from the engine bay (we’ll get into why cooler air is better). These are best used when either on a budget, or if space is a major constraint for your build. For instance, I installed one of these on my Jeep so I could mount an air compressor in place of the factory air box. Neat, huh?

Cold Air Intakes:

Here’s the meat of the industry right here. The whole point of a cold air intake is that cold air is denser, allowing your engine to bring in more oxygen with every breath. More oxygen means your engine’s computer can add more fuel, and those two together means more power.

aFe Momentum Cold Air IntakeThe way they go about this is to attempt to seal off the intake filter from the rest of the hot engine bay, and pull in only the cooler air from outside the vehicle. You’ll see a lot of companies claiming their products are cold air intakes, when in reality they’re just pulling in hotter air than your stock air box, which is no bueno.  These are generally more expensive than short rams, but are worth it if you can pony up the cash and don’t need the space.

Bonus Round:

BBK Larger Diameter Throttle BodyThere’s more to your intake than the tube and filter, we’ve also got larger throttle bodies, throttle body spacers, tuned mass air flow sensors, higher flow filters, and even snorkels for the offroad crowd.

Exhaust Systems

Magnaflow Ford Raptor Exhaust

Speaking of a rite of passage. This is one mod even non-car enthusiasts do, because who doesn’t want their car to sound badass? The pope? I bet even he wouldn’t mind. Anyway…

So if you’re bringing more air into your engine, it stands to reason that you’re going to need to open up the flow to get the spent gasses back out again, right? This is another one that works together with other mods to overall give you more power. Plus, who are we kidding, we want that rumble when we hit the skinny pedal!

Again, there are a few ways to get where you’re going here, depending on how far down the rabbit hole you want to go:

Cat Back Systems:

Usually when someone says they put an exhaust system on their car, this is what they mean. A cat back system replaces the exhaust from the catalytic converter(s) all the way back to the exhaust tips. The reason they start after the cats is one, for emissions reasons, and two, because catalytic converters are expensive to manufacture. Still, these systems give you more flow, and are the biggest factor in shaping your exhaust sound, as they include the mufflers and possibly resonators.

Corsa Cat Back Exhaust Mustang GTDepending on what you drive, you’ve got a ton of options. You can go from just a low, mean rumble, to an over the top screaming system for maximum power… that might also get you kicked out of your neighborhood. With these systems you also have some choice terms of materials, most common being aluminized steel or full stainless steel for corrosion resistance.

There are so many systems out there even from within the same brand, so here are some good manufacturers to look out for:

Exhaust Headers:

Here’s a question we get a lot: What’s the difference between exhaust headers and an exhaust manifold?

aFe Twisted Steel HeadersMost cars come with cast iron or aluminum manifolds, which are one large casting branching across all of the exhaust ports coming off the engine. Headers on the other hand have individual tubes for each port before converging into one pipe called a collector. These are designed with wider, smooth walled piping, with more efficient routing to make for better flow, and should be paired with a full exhaust system to really see maximum benefit.

Headers tend to be much more varied by application, but here are some of our best selling:

Performance Mufflers:

Magnaflow Muffler CutawayWhile a full performance exhaust system would be ideal in terms of power, your stock muffler could be a significant bottleneck on its own. Replacing just your mufflers can be a cost effective way to open up for more exhaust flow, and is probably the cheapest way to get the sound you want without getting too involved. Also, in many cases, aftermarket mufflers are a cheaper alternative to stock replacements if your factory muffler falls victim to rust.

The downside here is that while many full exhaust systems and headers can be bolted up in an afternoon, just replacing the muffler often times means cutting out the old one and welding in the new. However, there are exhaust shops all over the place that can do this for you for generally pretty cheap. There are pros and cons to everything!

Flowmaster Street Mufflers Sound Guide
Flowmaster sound guide. Click for the full size chart

The amount of aftermarket mufflers we have on the site is just staggering, but here are a few popular options:

Bonus Round:

Invidia Subaru WRX DownpipeAgain, modern cars are complicated machines, and there is always more to the equation than it might seem at surface level. Some other areas you can or might have to upgrade along the way (depending on your application) are things like downpipes for turbocharged engines, high-flow catalytic converters, delete pipes, and some sharp looking exhaust tips to top the system off.

Performance Chips & Tuners

DiabloSport Trinity T2 Tuner

Cars these days are seemingly just as reliant on software as they are hardware to get anything done. With that being the case, the reality the situation is that some of the biggest gains to be made need to be unlocked with 1’s and 0’s rather than turns of a wrench. This is especially true with turbocharged vehicles, where you can get more power out of just a tune than a lot of the above mods combined.

These tuners and chips do a wide variety of things, and many of them with screens or app pairings also serve as performance monitors and diagnostic scanners. As far as tuning, they work with your engine’s ECU to increase boost (if applicable), and overwrite the conservative factory calibrations for more aggressive mappings to allow your engine’s computer to get the most out of what it has available to it.

Performance Tuners:

RaceChip GTS Black Chip Tuner W/ AppDon’t worry, as usual the market has kept up pace with these technology changes, and depending on what you drive, you could be downright spoiled for choice, so here are some brands to check out:

Bonus Round:

k&n throttle control moduleLike I said, just about everything is computer controlled these days, even something as simple as the gas pedal is electronically controlled on most new vehicles. That just gives us more to tweak to our advantage, hence the rise in throttle response controllers. There are also performance monitors boards, speedometer calibrators for larger tires, and a whole lot more:

OK, I’ve got more power. Now what?

Chevy Corvette Horsepower Mods

Horsepower and torque are just one part of the equation for a true high performance vehicle. What good is all that power if your tires aren’t up to spec, your suspension can’t handle it, or your brakes can’t stop you?

If you’re still wanting more power, you’re likely going to have to venture into forced induction and tweak your engine’s internals. However, that’s getting a little outside the scope of what we’re trying to cover here, as this guide is really just meant to serve as an initiation down the rabbit hole in chasing after more and more power.

If you’re still looking to do some reading, check out some more guides below, otherwise you just need to get out there and drive!


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