Throttle body bore-out

[bowlsby]

I need any advice available from anyone who has bored out a 2.0 throttle body, to use with the stock FI.

Is there much noticable benefit to doing it?

Any recommended specialty shops that have done it before?

What new i.d. has been tried and successful for best performance?

Anyone have dyno results before/after?

Should the mixture be richened,(I assume to take it back to stochiometric balance)?

Is there anything else to it?

[neilca]

I have thought of these things and decided that the throttle body housing was to thin for a large enough bore. I was thinking of taking a second throttle body and making a two barrel. Run one throttle switch but balance mixture/injector flow for the additional air. You could even install a dashpot on the second throttle body such that it only opens when the engine asks for it. I would bet you would have to go with higher capacity injectors or even a second set of injectors that are actuated when the secondary opens. What a great problem for a tinkerer.
Have fun,
neil

[rich]

Has anyone ever seen a throttle body with a built-in secondary? Coool idea. instead of a second set of injectors you could have the secondary trigger nitrous oxide.

[roadtrp204]

CIS injection on water cooled VWs had a secondary in the throttle bore.
Chris