Will New Fuel Injectors Improve Performance?

One of the most common questions we get is, "Will new fuel injectors improve my car's performance?"

The answer is both yes and no.

Yes, it's true that replacing old, worn fuel injectors is an easy way to improve an engine's efficiency. If you have an older vehicle with a set of worn fuel injectors, replacing them will help your engine run like new. You may even notice that your vehicle accelerates better.

But replacing an old worn out part with a new working part is not the same as adding horsepower. If you replace a fully functional injector with a larger injector - and make no other changes - that usually won't make your engine more powerful. Increased fuel flow is important, but it's only one part of making your engine more powerful.

Here's more info about how a new set of injectors can improve performance and why

A New Set of Fuel Injectors Alone Won't Usually Increase Engine Power

We'd love it if increasing engine power was as simple as swapping out injectors. Sadly, that's not the case. A set of new, higher flow rate fuel injectors can put more fuel into the cylinder, but injectors alone won't necessarily make more power.

NOTE: We say "won't necessarily" because there a few vehicles that will recognize higher flow rate injectors and use them to make more power. But this is the exception and not the rule.

This is because increasing engine power is about adding both fuel and air to the cylinder. This is because fuel and air have to mix at a very specific ratio in order to facilitate combustion - too much of one or the other can lead to all sorts of problems.

Additionally, even when you can add more air to the engine to mix with an increased amount of fuel, you also have to reprogramming the engine control module (ECU). The ECU determines engine timing and needs to be programmed to adapt to any performance upgrades you make.

So, basically, if you want to increase engine power, you need:

  1. More air
  2. More fuel
  3. A new engine tune/ECU program

Fortunately, there are lots of ways you can increase both engine air and fuel flow.


Higher Flow Fuel Injectors Are A Smart Upgrade For Turbocharged Or Supercharged Engines

If your engine uses forced induction - eg a turbocharger or a supercharger - adding power is pretty easy. Because turbochargers and superchargers force air into the combustion chamber, they can usually be tuned to work with a set of higher flow rate injectors. In some cases, all you need to make significantly more horsepower is a set of new injectors and an engine tuner.

Of course, this isn't true for all forced induction engines. Some forced induction engines will require modifications above and beyond a set of larger injectors and an engine tune:

  • Undersized pulley (supercharger only). Many superchargers are belt driven, so you can increase the amount of air pressure the supercharger makes by spinning the pulley a little faster.
  • Swapping in a higher pressure blow-off valve. This increases boost pressure, which means more air is forced into the combustion chamber.
  • An exhaust downpipe upgrade (turbocharger only). Many downpipes can be redesigned to remove restrictions and/or emissions equipment, increasing the efficiency of the turbocharger in the process and increasing airflow into the engine.
  • Intercooler (or intercooler upgrade). Many turbocharged and supercharged vehicles either do not come with an intercooler or do not have a very efficient intercooler.
  • Air intake system upgrades. While the gains are lesser, an upgraded intake will allow more air to enter the engine.
  • General exhaust upgrades. Outside of a downpipe upgrade (turbo only), most exhaust system upgrades will help the performance of an engine with forced induction. Headers, high flow catalytic converters, and mandrel bent exhaust tubing with correctly sized mufflers can all increase engine power.
  • Engine programming and tuning. Last but certainly not least, modifying the program that controls the engine is one of the easiest ways to make a big improvement in engine power.

In concert with any of these other modifications, upgraded injectors are a very good idea.


What About Larger Injectors For Engines Without Forced Induction?

If your engine doesn't have a turbocharger or supercharger, increasing engine power usually requires more effort. For example:

  • Upgrading the air intake system. Simple upgrades like swapping out the engine air filter for a performance filter - our mounting a new air intake kit - can be a great way to give your engine a little more oxygen when it's running. While these upgrades increase engine noise a bit, they will increase the volume of air flowing into the cylinders, allowing for more fuel to be burnt (and more power to be made).
  • Replacing the air intake, cylinder heads, or camshaft(s). None of these upgrades is easy, but all can improve engine power by increasing air flow to the cylinder.
  • Adding on a turbocharger or supercharger. Adding on a supercharger or turbocharger usually requires a lot of work (and a lot of money), but it's one of the most efficient upgrades in terms of dollars per horsepower.
  • Installing a nitrous oxide system. Fast and Furious movie drama aside, nitrous is a cheap and safe way to increase engine power in the right hands. Nitrous oxide both increases the oxygen in the combustion chamber while also cooling the combustion chamber so the air is more dense (and therefore contains more oxygen). The combination of these increases is very effective in terms of performance.
  • Installing an E85 conversion kit. Depending on your vehicle year and your engine, it may be possible to add a kit that lets you run E85 in your motor without damaging anything. If so, E85 is very high octane (higher than some race fuels) and can increase engine power as much as 15%.
infograph about injectors

Where Can I Find Bigger Fuel Injectors?

If you've decided to upgrade to bigger fuel injectors, we probably have what you need. TLF Performance Parts is one of the only companies in the USA that offers both an extensive line of remanufactured OEM replacement injectors, an extensive line of remanufactured high performance fuel injectors, and a custom engineered fuel injector service. Our custom shop will work on fuel injectors for just about anything - from brand new cars to modern classics.

Finally, we're able to offer some of the best fuel injector prices on the market because we have fuel injector remanufacturing down to a science. We know how to refurbish old injectors to make them flow like new again, and with our extensive testing equipment we certify the flow rate of every injector we sell - even the high flow injectors designed specifically for high performance applications. This allows us to offer up to a 3 year, 36k mile warranty on replacement injectors.

Looking for expert advice? Chat with our founder, Tom Folder and get the professional input you need to evaluate your fuel injector needs. He's available to chat here - put his knowledge to work for you!