Header differences

[hecmanortiz]

I noticed on the Mazdatrix site that there are several(5 I think) different headers for 12A engines. How much of a difference is there really between the years and transmissions? I have an '85 with manual transmission and rats nest removed. Would there be a problem with a header from another year/transmission setup?

Thanks,
Hector

[RX-7 Chris]

You should just get the 16012 or 16125 header depending on if you want the single out or the dual out.

[hecmanortiz]

Thanks Chris, I was just wondering cause I just bought a used one off Ebay that came off a 12A and it wasn't specified. I thought the 12A headers would be the same till I checked at Mazdatrix. Other than O2 sensors I don't know what else would be different between the generations. Oh well we'll see when it gets here may be some wires and bungee cords holding it up.

[j9fd3s]

the 79-80 header will have a different flange and uses a different presilencer than the other headers, as the 79 "cat back", actually heat exchanger back, is a different length than the 81-85 systems.

i have no idea why there is a different header for 81-83 and 84-85. they all use the same size presilencer...

notice the road race header is 79-85, the difference in the others must be small

mike

[sgt.stinkfist]

its all in how the header/presilencer collects with the stock mid pipe which most RB exhausts reuse, and the hanger mount. for the road/race dual out header, it doesnt matter... one header fits all in that case, as it uses a different dual center section and RB's muffler for the '82 chassis w/ the dual inlet