Take the throttle body off and measure the size of the intake opening. It won't do any good to buy anything larger. Is the exhaust large enough to handle the increased flow?
there is also the issue of fuel pressure...wouldn't you be better off talking to a machinist for a second throttle body with a second injector?
Stock should be around 60 or 65mm, and you can increase it with a new one up to 75mm. But like tenspeed mentioned , you will only see an increase if you do heads and exhaust,etc. An engine is just a big air pump, so air going in, must come out.
^unless the throttle body/plate is a restriction causing drag. As tenspeed said, dont go bigger than the Intake manifold inlet for obvious reasons. The larger TB with also give you increased throttle response which is nice. On a side note, you 3 are post whores, arent ya?
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