Can a Larger Throttle Body Really Increase a Car’s Horsepower?

If you’re planning on modifying your car for more power, then there are many different parts that you can add to it. For most cars, you can add parts like a new exhaust system or manifold, or perhaps a new air intake. But what about a larger throttle body? Could that add more horsepower?

The throttle body adds air into the engine

A large throttle body
A large throttle body | Amazon.com

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In order for your car’s engine to work properly, it needs to have air pumped in and out of it. the throttle body is located after the air intake – at the end of the intake manifold – and is essentially the gateway between the air that’s being sucked in by the air intake and the engine itself. Inside the throttle body itself, there are two flaps that open and close. According to It Still Runs, when the accelerator is pressed, the flaps on the throttle body open up and allow air into the engine.

A bigger throttle body means more air

Now that we understand how a throttle body works, we can delve into why making it bigger could be better. If you expand, or increase, the size of the inner diameter portion of the throttle body, more air will be pushed into the engine. And since the engine is basically a large air pump, increasing the air intake level will increase the engine’s power output as well, in some cases by up to 15 to 25 hp.

Car ID reports that “packing more air into your engine allows more fuel to be burned, which creates more power.” Fortunately, there are sensors on your engine that monitor its air/fuel rate, so you car’s ECU should be able to compensate for the added air. But in some cases, you might need to tune the ECU to adjust to the new air/fuel ratio, typically if you have other power-adding modifications as well.

In those cases, tuning the ECU is paramount as the air-to-fuel ratio in any engine needs to be at the optimal range to make more power. Having more air, but not enough fuel, going into the engine could lead to no extra power being made.

You can expect an increase in throttle response

A picture of a throttle body
A picture of a throttle body | Wikimedia Commons

While increasing horsepower is the main reason anyone would add a larger throttle body to their car’s engine, another benefit is added throttle response. Many auto manufacturers measure a car’s airflow at the peak RPMs and then choose a throttle body that ensures 50% of throttle will produce 50% airflow, according to Car ID.

While that formula works for everyday driving, it’s not optimal for those seeking more performance out of their cars. So when you add a larger throttle body, you’ll feel a sharper increase in the engine’s responsiveness, especially at a higher RPM, since the engine’s airflow is increased.

Other engine modifications will make more power      

Another benefit to adding a larger throttle body to your car’s engine is that any other modifications that you add will make more power too. Since you’re adding more airflow, other power adders like a supercharger, turbocharger, or even simple bolt-on parts will make more power as well. However, just make sure to get the correct throttle body size for your specific application.