are there any differences between turbo and n/a rotor housings? also the same question on series 4 and 5 rotor housings.

 

check the mazdatrix site,in the FAQ. They have an explanation on the diference, a believe is a water hole.

 

1988 turbo rotor housings vs 1990 turbo rotor housings, Mazda has changed the spark plug location. And some other changes.

 

YES, to answer the question.

The biggest difference is the type of plating used on the housing.

Turbo housings use a different grade of plating (higher wear resistance) and allso they have teflon baked into the micro pours of the surface for emergency lubrication if omp fails. You will see this baked out of the surface if you ever TIG weld in a peripheral port in a brand new rotor housing.

They are more durable compared to n/a housings, but most people end up having engine failures before they notice the incresed wear resistance !!!!

 

According to Mazda the chromium plating was changed in 1984 from pin-point porous chromium plating to microchannel porous chromium plating.The plating hardness was also increased by 20%.The changes were made to 12A and 13B housings.The purpose was to improve oil retention of the surface,prevent chatter marks and vertical scratches caused by the apex seal and general durability.At that time a fluorine coating was added to the 13B housing to improve the initial seating between the apex seal and the housing.
The teflon impregnation came later.

 

There is a *splitter* in the exaust on the N/A verses the turbo ref:http://www.mazdatrix.com/faq/6pexh.htm