This thread is very old and some of the members in it may not still be active.

But why do you need a new throttle body? There isn't really anything to break on them, that are pretty much a hunk of aluminum....

 

Does it even improve mpg or acceleration? does it even improve anything? lol

 

The bolts holding a part to it snapped (not the MAF but the thing with a spring. So it won't hold it down. Also a friend of mine said getting a wider throttle body allows more air in the engine which in turn creates more hp. So, does anyone know what wider throttle bodies I can use for my 03 carlo ss?

 

if you do not have any mods on your car you do not need a bigger TB. the stock TB has plenty of flow. if you were to install a cam/rockers and headers then just maybe you could see a benefit from extra flow but it would be minimal. with SC'd engines people upgrade the TB because as the pulley size is dropped more and more air is drawn in. when you get to the 3.2 or 3.0 pulley size it is suggested to switch to a larger TB. on an NA engine a larger TB will actually lower the velocity of the air entering the engine and the velocity of air being pulled thru the intake. this decrease in velocity will hurt TQ and not produce any HP increase.

 

What Z34Phoenix said
You need supporting mods to go to a larger t-body. If a bolt snapped, just drill and re-tap it. If you still want to replace it, you can use any t-body from a L36 in the junk yard from 2000+ I believe. GM has 2 different t-bodies on the L36 ('99 and older have a "maf bridge" and use one style MAF as a result, then the ''00+ have a MAF "hump) and use a different style MAF). You can see the differences in my attached pics.

Same hump/bridge is true in the L67.

But don't bother with a larger t-body unless you have mods to go with it. And since these cars are so plentiful, they should be easy to find and cheap from a junk yard.

 

A larger TB would make you think acceleration is improved at part throttle in the short term. You get more airflow for the same throttle opening percent.

Let's say you typically use 25% throttle to take off from a light. With a larger TB, at the same 25% pedal position, you're now getting the same airflow as you did at 40% throttle position before (just throwing a number out there for comparison purposes)- so it will make it seem like it's more peppy cruising around (at least until your brain gets used to the new throttle response, and you stop pressing the pedal as hard).

However, actual full throttle acceleration will be minimally impacted because you're going WOT to achieve maximum acceleration - and as I had mentioned earlier- since the rest of the system is roughly the same size as before, WOT airflow will be roughly the same as before.


A larger TB is helpful for a SC engine in that if everything else is made larger to match- you reduce restriction going into the blower, which helps improve efficiency, and lower outlet temperatures. For an NA engine, it's not as big of a deal - there are usually other mods you can do with better bang for the buck until you've got a good number of engine mods under your belt.