Okies... I've done the de-restricting of the airbox... had a look at the guide here: viewtopic.php?f=14&t=10729
but i can only assume that is on a different car? (astra maybe?) as the airbox layout is different in my Vectra B.
Soooo... i did it a slightly different way. the plastic pipe in the top half wasnt too tricky to take out (pushed in a couple of bits of plastic with a screwdriver and then pulled it out) and the intake pipe in the bottom half was a metal coil covered in fabric held in by 2 plastic shells. i prized these shells out slightly and pulled out the pipe. I then positioned the shells and the pipe so that it was just inside the bottom half of the airbox, then cut the length of pipe down to the required length on the outside of the airbox so it still slotted into the intake.
I've got a few pics if anyones interested....?
One question... why the hell are those pipes so far into the airbox anyway? surely it would make more sense for vauxhall to have left those pipes as the are now?... there was only an inch or so of space between the end of the pipe and the airbox... cant have been good for air flow??