You're going to get a lot of different opinions on this subject. Some people swear up and down that the 1.6 is a better motor for turbo charging simply because its higher reving. I don't have any experience with these, however I did assist a friend in installing a Flyin' Miata kit on his 1.8. His car was basically an FM2 car with the FM1 intercooler and a small exhaust. I believe he made somewhere around 210 rwhp with a lot of it being limited by the tiny intercooler/exhaust combination. I will tell you, it was a fun little car to drive even with just 210 whp. 300 would be a blast.