Can i use the same cold air intake for an n/a for a turbo engine?

 

I Dunno Man But If Not Ill Make One And Slap On A K&N Filter

 

Yes, if the cars are the same series (86-88 or 89-92). However, if the NA filter is very small, and the turbo engine is modified for a lot of power, then the NA filter may restrict the airflow more than it should.

 

Okay, is there some sort of rating on the intake that would let me know if my turbo engine is suitable for it?

 

No, the automotive aftermarket parts manufacturers rarely test their own products, and they usually assume that their customers do not have the education to understand any physics ratings.

For K&N brand filters, I derived the stupid Evil Aviator K&N filter rule of thumb, which hopefully isn't any more stupid than the other stupid internet guidelines:

Horsepower Potential = Filter Media Area square inches * 4.53

If you have a filter that is 'too large', there will be no significant ill effects, and the filter will last longer between changes or cleaning.