Engine stock 2lt?You can use gt18v vgt turbo from saab opel and parts from a zexel frontera 2.8tdi fuel pump to make your pump 11mm from 7mm stock.Then you can achieve 140HP easily
It's not neccessary.Most important is that you have an boost gauge and exhaust gases temp gauge EGT to control temp.I have such a modification in my 2lt toyota.The difference is abnormal :)
