up pipe goes form your headers to your turbo. you can not see it from looking under the hood unless you really know what your looking for. as for the stock turbo handling 18psi i have heard that that is true. but remmeber you shouldnt do it with stock engine managment, i wouldnt do it for very long, and use a higher octane gas will your at it. other then that the turbo would probaully fry, along with your engine.

I think when you said that you installed the egt in your up pipe you where thinking the down pipe is the up pipe. what kind of egt readings are you getting.

attached to the exhaust port from the engine is the headers, then up pipe, then turbo, then down pipe, mid pipe, then kat back, or axle back (i think they the same thing but im not sure.)

Most of what ive said is just what ive learned doing reading, searching, or just plain car chat. I would get a second opinion.