[01-yellow-ZX3]

Quote:the butterfly is still the same size, and in essence will take in the same amount of air. The idea of "porting" your throttle body is to make it bigger, but you're not doing that....

Totally untrue.

Why do you think people do this then? For fun?

The stock TB isn't necessarily taking more air in, but its definitely taking more air in EARLIER. Thats why throttle response is increased, and this is why people spend the time to do this.

The stock TB on a Focus is what 57 mm? But, a few of these mm's are affected by the huge lip on the stock TB. For anybody thats actually seen a stock throttle body, they know what I'm talking about. By porting a stock tb, you're not increasing that stock 57 mm, but you are taking away that lip, in return gaining some more air coming in.

I've driven a Focus with an aftermarket TB and a ported stock TB. I would never spend the extra money to get the aftermarket over a stock ported. If I were you, I'd definitely buy a set of cam gears. Do some research and find the hp/tq increases people have gotten with dyno tuned cam gears, its amazing.