best place to start tuning is the breathing, getting air to the turbo, cold air, via a straight pipe with a cotton base (or similar) filter.
next, the intercooler, no good in the wing, needs to be on the front of the car, 'front mount intercooler'.
thats the basic hardware in terms of breathing.
If you can fir a bigger turbo - but not too big, even better.
Next, chipping on a rolling road, this is where your hard work on the breathing pays off.
Don't know much about the 1.9, but my 2.4...
went from 140bhp stock (often produce less on the RR, to over 200bhp RR with breathing sorted and chipping, turbo standard, no black smoke.