Is it possible...

to intercool a 87 mercedes turbodiesel???:evillol:

Of course it is. you just fit an intercooler between the turbo air outlet and engine air intake. you'll need some piping and stuff, but it can be done easily.

where would i put it like behind the radiator on top of/in front of the engine
and what size intercooler would i need?
thanks

size depends on power requirements and efficiency.

putting it on top of the engine is counter-productive unless there's a scoop and air can flow out from under the intercooler. (it needs lots of airflow if it's about the engine because engine heat rises and causes heat-soak, so efficiency actually drops)

the best place for the intercooler would be in front of the radiator, and 1.5ft wide by 1ft tall and 3" deep would provide decent cooling if the airflow is good.

if you haven't done this before it's best to take to a custom fabrication place who can get the right size intercooler core, make the end tanks and sort out the piping.

don't expect to see a big difference from an intercooler alone, maybe 15bhp and 15lb/ft increase.