Throttle Body

Author
Discussion

YarisSi

Original Poster:

1,538 posts

251 months

Saturday 1st May 2004
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Can someone explain to me the difference between carbs and the above? Why is it throttle bodies give better performance?
Thanks

jimbro1000

1,619 posts

291 months

Saturday 1st May 2004
quotequote all
Just briefly:

Throttle bodies are a cross between carburettors and the common plenum-chamber style of fuel injection.

You typically get one barrel per cylinder, each with it's own throttle butterfly and, in normal circumstances, injector. Some systems use two injectors per body for high rev situations.

All of the shaping technology developed for carburettors come into play which means some people are far more comfortable with the it as it is somewhat easier to understand. Hypothetically speaking more recent developments like direct injection would be better but this is not something that can be "bolted on" to improve performance.

Much of the clever work comes from the engine management that runs the throttle body and the air flow characteristics. It is the air flow limitations of the plenum chamber system that tends to strangle power delivery

cptsideways

13,648 posts

259 months

Saturday 1st May 2004
quotequote all
Above is correct

Think you'll find it simply a case of a very short direct air feed into the engine, as opposed to going through an entire manifold system.

This type of system is not actually more powerful but it allows the engine to rev a lot higher and more revs with the same torque = more power. If you add engine management then power can also increase through mapping etc.

YarisSi

Original Poster:

1,538 posts

251 months

Saturday 1st May 2004
quotequote all
So Direct Injection is actually better than a throttle body?
Thank you for explain that to me.

annodomini2

6,912 posts

258 months

Saturday 1st May 2004
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Direct injection is theoretically better than a throttle body, but requires a special head design and of course you don't have the option of a second direct injector if you wanted to add one to an existing design.

cptsideways

13,648 posts

259 months

Saturday 1st May 2004
quotequote all
Throttle body is where the air goes in & you can fit an injector there which is the convential position, air & fuel mixes as it goes in.

Direct injection is where the injector squirts directly inside the combustion chamber at very high pressures where the fuel is atomised inside the chamber