After hearing lots of praise for the performance gains of a bored throttle body I decided to be a typical cheap ass and bore my own. I went to the junkyard and got a used throttle body for $35.
Start by disconnecting the air intake, throttle cables and sensors. Then remove the four bolts that hold the throttle body on. After it's off remove the old gasket.
To bore the new throttle body I got a 2" sanding drum and put it in the drill press. I sanded away until the hole was 60mm. Basically you'll just want to remove the taper in the bottom of the throttle body. It's an easy process. Be careful not to widen the space the butterfly closes or it will scew up your idol and make the throttle body garbage.
Then just bolt the new one on and hook up the sensors and throttle cables.
This is what the old throttle body looked like. You can see why it's a good idea to clean it from time to time.
When all is said and done you should notice a difference in acceleration and power.
