mate, all you have done is criticized what i have said, why dont you try and contribute something, instead of being a heathon.

No one cares for ppl who criticize others and contribute nothing, take your s**t to ebay!

as for pipe selection, sunbury23, you size the pipe to the motors potential, and where you want it to make power. if its only ever going to have a small set of extractors, use a 2.25 inch mandrel bent pipe with free flowing mufflers and cat. this keeps up low down velocity for torque while freeing up the factory restricted top end. If you are going to do a bit of headwork, and/or get a cam and tune, 2.5 inch is the way to go to maximise the benefits. only ever go a 3 inch if the motor is worked pretty hard, a 3 inch will see a loss of torque down low until around 2500-3000 rpm, as going too big sees the flow velocity slow dramatically, resulting in low rpm restriction.

with the extractors go as far as you can on the budget. if you can afford comp paccies and want them, get them. if you cant, get budget ones off ebay. the difference might be 3kw and 7 nm (give or take with the brands and types). I know which id prefer on my car

motors, im told by my old man, go harder right before they pop..