i passed off my Lupo SDI, and discovered the glorious world of the MK2 golf about two years ago however, i was dabbling around with diesels. the turbo fitted to the above SDI, is the same as a AHU/1Z. you will need a mk4 tdi downpipe mind.. Actually... its the same turbo as a LUPO tdi. (manifold is different mind..) so lupo tdi downpipe might be better? im not familiar with the SDI block but a quick google.. tells me you can get a turbo oil feed from the top of the oil filter housing (currently blanked off) as for oil return, there MIGHT be a blank plug on the back of the block (i know the MK4 SDI engine is like this - so is the 1.9 D i just cant get a good image on google of the AKU) in which case you can use the factory oil return a TDI would use, or if not, remove the sump and get an AN- fitting put on there near the top of the sump and then use AN fittings for oil to return straight to the sump. inlet? VW Transporter t25 1.9 TD inlet like shown above, and then some piping to the turbo! as for fuelling? like said above 1.9 tdi injectors and MAYBE injection pump. it would then need a real custom map! of course, could fit a landrover 300TDI diesel pump and bin most of the wiring and tune it with screwdrivers. no idea on CEL lights, etc.. however again from above, you cannot go over about 98hp without your clutch taking a steaming hot one. if somone were to give me a lupo SDI, i would happily try all this out and make a proper guide.(kinda why im hovering around this forum) as for now.. i have no idea on fuel economy, i have no idea who could map this, i have no idea on uprated clutches, i have no idea on torque figures - top speeds etc, i have no idea on smoke amount.