Why do ITB installs move the injectors to the TB?

[The Fatty]

Why do ITB installs move the injectors to the TB? Whats the gain as opposed to being in there normal location? Is it really required? is that the point of ITB's? I always thought it was for increased air flow?

 

[Cupman29]

Where else are you going to put them? All you have is a trumpet and the TB and maybe a spacer.

 

[Dan@SJM]

The normal location is in the manifold. Which your replacing with an itb manifold.

 

[The Fatty]

that makes perfect sense then lol. For some reason I thought the injectors were screwed directly into the engine block. silly me

 

[Chip-mk1]

Depends on the engine. Williams lumps they are straight into the head.

further away is better for high rpm but worse for idle emissions.

Serious itb setups run 8, 4 near the head and 4 further away.

 

[The Fatty]

Ah ok that make sense. Didnt think all of them were via the inlet manifold. So the 8 injector setups I guess put half the amount in at each stage? allowing for a perfect mix to happen? that sounds very interesting! thanks Chip.

 

[Chip-mk1]

No you phase the delivery backwards as revs increase if you want it optimum, so at high rpm you are just on the furthest 4, at low rpm just the near 4