Lets cut out the pure tosh first, uprating the intercooler, fitting bigger exhausts, or increasing the turbo boost will not work, this is pure myth and pure unadulterated crap.

Modifications need to be structured and compliant with one another to ensure success. Diesel engines work by injecting a quantity of fuel into excess air in the combustion chamber, note the "excess" air. so uprated turbo boosts, and intercoolers are useless unless an increased amount of fuel is injected also. Uprating wastegates, intercoolers, and exhausts allows more fuel to be introduced, thus more power.

Fourtrak engines were marinised for use in boats, these produced around 140 bhp, but significant modifications were not necessary. Contact a diesel injection specialist who specialises in Bosch systems as this is what is fitted to your vehicle, they will advise you what modifications are possible with this injection pump.

Once you have this information, it is possible to work in the induction system, particularly the increased turbo boost, increased airflow, and intercooler design, etc.

Do not forget the all important testing and considerable work involved in setting the engine up to meet emissions standards, ensuring it is legal.