Throttle Body Upgrades: Do They Actually Work on the HEMI?

A bigger throttle body is one of those modifications that sparks endless debate in the Challenger community. Does going from the stock 80mm to a 87mm or 90mm throttle body actually do anything? The answer is: it depends on what else you've done to the engine.

How It Works

The throttle body is the valve between your intake and the intake manifold. It controls how much air enters the engine. A larger throttle body allows more air to flow at full throttle — but only if the engine can actually use that extra air.

When It Makes Sense

A throttle body upgrade provides the most benefit when you've already opened up other restrictions in the air path. If you have:

• A cold air intake (feeding more air)
• Headers (exhausting faster)
• A tune (optimized for increased airflow)

Then a larger throttle body removes the remaining bottleneck between the intake and the manifold. In this context, a BBK 90mm throttle body can add 10–18 HP.

When It Doesn't Make Sense

On a completely stock engine with stock intake and exhaust, a bigger throttle body gains very little — maybe 3–5 HP — because the rest of the system can't flow enough air to take advantage of the larger opening. The stock 80mm throttle body isn't really a restriction on a stock engine.

The Recommendation

Save the throttle body upgrade for after you've done intake, tune, and exhaust. At that point, it becomes a meaningful addition to the airflow package. Think of it as the cherry on top of your Stage 1 build, not the first thing you buy.

Top pick: BBK 90mm CNC-machined throttle body. It's the de facto standard for the 5.7L and 6.4L HEMI, with excellent fitment and proven gains in combination with other bolt-ons.