What is meant by the series designation, e.g. Series 4 RX-7?

To my knowledge it was only an Aussie/NZ thing, but I could be wrong. As far as what I've seen that's the only places they're called that. Basically they split the gen's up by what I guess are different years or whatnot. Maybe check out the FD Kai site from NZ...they might have a description there. I'll post the link once I find it...IF i can find it :)

Thanks for the info. I got the series thing from an Aussie site, autospeeds.com. I was curious because they recommended an ic from a Series 4 RX-7 as a decent alternative to aftermarket cores. I have a z31 turbo that I want to intercool.

A cheap alternative would be the core from a Mitsubishi Starion/Chrysler Conquest TSi. I've seen quite a few people with different cars use the core from one of those. They're probably super cheap and easy to find at a junkyard or salvage yard or even on Partstrader.com.

Year / Series / Gen / Vehicle Description (comes after the JM1 in the VIN)
78-80 / Ser I / 1 Gen / SA22C (aka "SA")
81-83 / Ser II / 1 Gen / FB33 (aka "FB")
83-85 / Ser III / 1 Gen / FB33 (aka "FB")
86-88 / Ser IV / 2 Gen / FC3S (aka "FC")
89-92 / Ser V / 2 Gen / FC3S (aka "FC")
92-95 / Ser VI / 3 Gen / FD3S (aka "FD")
96-98 / Ser VII / 3 Gen / FD3S (aka "FD")
99-01 / Ser VIII / 3 Gen / FD3S (aka "FD")