Turbo is the one of the expensive mod you can have on a car because it require
to change the engine compression ratio therefore you have to change ECU.
Turbo also produces a lot of heat, so a improved cooling system is needed. You
will also need oil system to supply oil to the turbo so it won't just die
since it is spining at 10K rpm An intercooler is also needed if you want the
turbo to live long and happy (relatively speaking). The engine itself may
need to be modified because the aftermenti