Leveraging Butterfly Valves with Challenger Throttle Bodies

In simple terms, a throttle body is a butterfly valve placed in between your car’s air filter and intake manifold. Its sole purpose is to regulate the amount of air pushed into the engine, based off of driver input through the gas pedal. That said, when the accelerator is pushed, the throttle bodies open, allowing more and more air to be let into the engine. From there, the engine then adds a proper amount of fuel to achieve a correct air/fuel ratio, helping your Challenger accelerate.

Throughout the history of cars, there have been two different ways of controlling the butterfly valve within the throttle bodies—cable drive and drive-by-wire. For years, the throttle body’s opening and closing have been controlled by a cable connected to the gas pedal. Step on it and the cable pulls the butterfly valve open, allowing air to enter the engine and create power. Let off the pedal and the throttle body closes and the car begins to decelerate. Simple stuff.

Drive-by-wire throttle technology—or electronic throttle control—is becoming the norm in modern cars, like the Challenger. With drive-by-wire, instead of the gas pedal connected to a throttle, it is instead connected to a position sensor. This sensor is wired to the car’s engine control module (ECM), which takes the position of the sensor and then tells an electronic motor how much to open the throttle bodies. 

The two accomplish the same job, but there are clear advantages to drive-by-wire. First, drive-by-wire offers more precision than cable drive throttle bodies, which result in better throttle response and fuel economy. Secondly, the electronic method eliminates moving mechanical parts, resulting in less weight and lower maintenance over time.

Let’s set things straight. Larger aftermarket throttle bodies aren’t necessarily designed to add horsepower to your Challenger. They support power. Larger throttle bodies are built to allow your engine more air to breathe, which will help take further advantage of other internal modifications and power adders. Thus, letting those pieces produce more horsepower.

Why upgrade throttle bodies then? If you’re thinking you want to build a high horsepower Challenger, you’re going to need more airflow to extract everything that the modifications have to offer. Throttle bodies will also increase throttle response and give more life to your Challenger, modified or not.

When is the right time to upgrade the throttle bodies on your Challenger? Well, it’s pretty subjective to the current build and goals of your car. Take these points into consideration.

Throw an aftermarket throttle body at a showroom stock Challenger and you’re not likely to see any power gains, only increased throttle response. The reason being that in stock form the car’s engine will benefit only slightly from the extra air coming in, but it won’t hurt your Challenger (unless it’s far too big). In fact, it’s often recommended to slap on a throttle body sooner rather than later, if you plan on making internal modifications down the line.

If you have upgraded with or plan on using a positive displacement supercharger (such as a Roots or Screw Type), adding a set of larger throttle bodies is necessary to take advantage of the extra power the supercharger has to offer. The reason being that a positive displacement add on still needs to suck as much air as possible, therefore it will benefit from the larger volume passing through with extra horsepower and improved throttle response. 

On the contrary, a build with a centrifugal type supercharger or turbocharger will not benefit as much from larger throttle bodies, as each power adder still needs to push the air through the throttle bodies. A build with either of these power adders will see small improvements in power and throttle response.

Yes, just because a throttle body is bigger doesn’t always mean that it is better for the performance of your Challenger. In a stock or slightly modified Challenger, a larger aftermarket throttle body will push too much air into the engine—actually causing it to run sluggish and hurt your throttle response. Without additional fueling modifications, it can force your engine to run a lean air/fuel ratio, which can be damaging.