Hi. I am currently rebuilding an unfinished RX7 project. The car is a 1989 rx7 NA with a 3rd gen twin turbo engine swap.

My question is That I am trying to figure out what is that hole on top of the turbo drainline on the left side of the exhaust manifold.

I have a picture but not so good at posting pics.

 

It would be better if you could post the picture. Is it on your phone or your computer??