Dude...punctuation is a beautiful thing.

Are you putting A6 pistons into an A1? Or the other way around?

Putting A1 pistons into an A6 will yield roughly 11.5:1 compression.

Putting A6 pistons into an A1 will yield really low compression. You'll be running less than 8:1. Even for a turbo, that's too low.

A6 and A1 pistons use the same rods and wrist pins. Not sure about the rings.