Throttle body, Does size count?

AC Bill

Well-known member
Watching Street Outlaw's on the tube last night. Daddy Dave had just rec'd a new, larger, throttle body. He was explaining to his buddy how the larger throttle body would allow more air into the engine, so it would increase the horsepower. Nothing about adding larger injectors, changing the MAFF, timing, tuning, etc.. He proceeded to remove the smaller one, then discovered the new one was wrong and wouldn't fit.. Typical lol
So did he just skip all the details on what else would be needed to best benefit the larger throttle body, or could you actually pick up some horsepower with nothing more than swapping to a larger throttle body?

I have a Trick Flow Street Heat intake manifold, with the 75mm intake plenum for my 5.0m that I could bolt on with a larger throttle body, I seriously question if that alone would be even worthwhile, without changing injectors, heads, cam., etc etc,..

Short answer. The article is accurate.

For the throttle body to have significant return, it needs help from supporting parts and tuning.

An engine is a big air pump.
The throttle body is one component of a longer plumbing network to route all that air.
Other parts of that network include, but not limited to, inlet tube from air filter, intake manifold, heads, cams and exhaust.

If you only make one of the components larger you still have restriction in other parts of the network.

So, yes, for one piece to return best results it needs support from rest of network.
Cams, heads and high flow exhaust such as long tubes and good flowing pipes and mufflers.

On modern cars, let’s say 2005 cars and newer, changing the tb requires a tune otherwise it will throw codes.

And even with the tuning, a tb on a mostly otherwise stock car is worth only about 3 hp.

But start supporting with all the other parts and the numbers climb and climb.
The numbers climb as a system, not as one part.

You don’t necessarily need injectors.
The computer controls the flow of those up to their max output.
Your tuner will know if you need larger ones when your car goes on the dyno.

The tv show left out some info.
But the guy you talk about probably had some, a lot, or all of the rest of his plumbing upgraded so he knew a tb would make a difference.