Here are some of the challenges involved in turbocharging a Mark 4 Fiesta Zetec:
* The engine is not designed for forced induction, and will need to be strengthened to withstand the increased boost pressure.
* The fuel system will need to be upgraded to provide enough fuel for the turbocharged engine.
* The exhaust system will need to be replaced with a larger, freer-flowing system.
* The engine management system will need to be reprogrammed to account for the turbocharger.
In addition to these challenges, turbocharging a Mark 4 Fiesta Zetec can also be expensive. The cost of the turbocharger itself, as well as the other necessary components, can easily add up to several thousand dollars.
For these reasons, it is generally not recommended to turbocharge a Mark 4 Fiesta Zetec unless you are an experienced mechanic with the necessary knowledge and resources.