4.3 gm throttle plate "mod" What do you think?
 

Your high performance 'airflow' parts source for GM / Chevy 4.3, 5.0, and 5.7 Vortec Engines Everyone on every gm truck forum is praising this "mod" for horsepower, throttle response, less throttle at highway speeds? My guess is they're just happy to chirp the tires. I'd imagine GM put it there for a reason. Fuel efficiency? Distributing even air flow to all cylinders? I've been searching for the pros and cons but I'm only finding everyone praising it. I'm lost! Just wondering what you guys think. My guess is it would use more fuel with a bigger throttle body opening?

it's a bored TB... you'll flow more air with the same amount of pedal movement. fuel economy should be identical, possibly slightly better with the larger TB depending on how much code in the PCM is TPS dependant.

smaller TBs are much less finicky to drive, when GM went over to the drive-by-wire throttles, they got much larger since the human factor of not being able to depress the pedal to the correct height is removed since now the PCM controls it.

I should have been more clear with my question, sorry. What is the blade on the stock throttle plate for? It's there for a reason right? The info on the electronic TB's is good to know.

maybe i'm blind, but i don't really see a difference in them.

from the way they're describing it, the purpose of the "restrictor" is for drivability. it sounds a lot like progressive throttle linkage, allowing you to move the pedal a lot when at low opening without much actual throttle movement, but opening fully when the pedal is completely on the floor.

finding a picture that actually has a decent resolution was more difficult than i thought...

http://i75.photobucket.com/albums/i3...7/IMG_0587.jpg

at least i can see it now... definitely dual-purpose in that it will make the throttle less jumpy at low openings and it will also restrict maximum possible airflow.

So in your opinion would you reccomend doing this for fuel economy? Or should I just leave well enough alone?

doubt you would see any return.

Last year, I installed a Volvo throttle plate (that had this wedge) into the throttle body of the gasoline engine of my Dakota. The Volvo and the original throttle plates had the same diameters, but I had to drill out a couple of holes in the Volvo plate in order for it to bolt up to the Dakota throttle shaft.

The idea was to reduce throttling losses due to the fact that there was this really aerodynamically ugly obstruction in the intake airflow. I calculated that said airflow reached speeds of about 60 MPH at the point where it met the throttle plate. If I had a single larger throttle opening (as opposed to two tiny sliver openings), I figured that it might cut down on throttling losses.

However, I did not see anything definitive, either for or against. Maybe I'll try it again this summer.

what i have read it was added to help the EGR blend with the incoming air charge better,,it would add swirl