TDI Tuning

Any of you guys had any dealings with tuning boxes that plug into the electric type Diesel pumps ,I have a 1z tdi in my mk1 and have been looking into doing a few mods to it for a bit more poke. Any other good tuning tips would be a good read for me especially if they come with part numbers, looking forward to hearing from anyone

 I have done both a remap and added tuning boxes. The remap was on a 2L tdi Quattro A3 PDI (8P engine) which went from 170 to 210 bhp and 30 mpg around town to over 50 if the missus was driving. (I have the pak files if anybody wants a copy).
I currently have a V6 Navara with a DTE box and all I would say is that it is awesome. Either option works by increasing the injector dwell time ( time the injector is open) for a given airflow/boost pressure/rpm calculation. The tuning boxes are rather coarse whereas a good remap can be very precise through out the rev range. If you go for a remap my advice would be go for someone reputable as there are a lot of idiots who buy the software and the interface cables
If remember correctly the MK3 TDI Z1 had a garret GT15 turbo which if in good condition could handle up to 1.2bar/ 18psi boost. I think it involves a bit of soldering of a potentiometer on to the ECU. My mate tweeked his MK3 tdi, bigger intercooler, remap and variable boost ripped off the cat and it would leave my mk3 16v standing ( but then again that was not very difficult in those days)