Difficult engine to play with. Van Arken and Novitec have done work on them, but you need to spend serious money.
All I am letting on about mine is that I put a SuperSprint exhaust on and a BMC air filter. I am testing out a CDA and will let you know how good that is soon.
Alfa Romeo 156 2.4 JTD (210BHP)
Fiat Punto JTD (130BHP)
Fiat Barchetta
http://www.angeltuning.co.uk
http://www.bravo-guide.co.uk THE Fiat Bravo site