How did they get the extra 25 hp?

 

sliightly different turbos (better air flow) i believe. plues japan dosent have as strict emmisions as the states so they can tune them to get more power out of them. someone correct if i am wrong

 

There were a number of detail changes which added up to the extra horsepower. Besides a change in the type of turbos, they also upgraded the engine computer and eliminated the pre-cat. For a detailed list of the changes read through this webpage:

http://www.rx7.net.nz/newrx7.htm

 

Cool, Thanks