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Retro Rewind: Driving Mazda's RX-7 FD rotary wunderkind


#1

The early ’90s were an exciting time to be a Japanese sports car designer. The yen was up—waaaaaay up—and as a result, the domestic market was thirsty for the latest and greatest go-fast tech wrapped in alluring sheet metal and glass. It was the tail end of Japan's infamous bubble economy, but no one knew that yet, and the result was a phalanx of the finest near-supercars to ever simultaneously emerge from the island nation.


This is a companion discussion topic for the original entry at https://www.hagerty.com/articles-videos/articles/2018/05/28/driving-mazdas-rx-7-fd

#2

Enjoyed the article of a car near and dear to me. I go back to 1981 for my first rotary. IMO, it was emissions (CARB) and CAFE that ultimately spelled the end of the RX7 in North America. The 3rd Gen. continued production thru 2002 in RHD overseas. And the reference to a turbo-timer brought a snicker, since the turbos are water-cooled and idling stationary only serves to raise temps, not lower them.


#3

I thought you might enjoy this one @Jim-R!

I agree with you on the “turbo timer” that got added to so many cars over the years. The problem of coking oil is no joke, but with water cooling being added to the turbos, like you said, it is no longer something to worry about that much.


#4

You guys git it wrong about the use of turbo timers on these cars,after a hard run the coolant and the oil will overheat in the turbo area.
You can actually hear the coolant boiling in the turbo housing after a quick shut down. Oil coking is also a problem
My 93 MR2 Turbo has 170k+ with original turbo and timer installed.


#5

No. Timers were all the rage 20+ years ago with everyone installing them right after under-body lighting and park bench spoilers. Water-cooled turbos really don’t benefit. Sit at idle for any time at all and watch your temps rise. Oil temps too. Unless you come off a hard autocross or track run and immediately shut down, thermosiphoning will be sufficient to avoid coking. And remember, oil formulations, especially with regards to synthetic oils have also come a long way in the last quarter-century. Much more resistant to coking. I also have my original journal bearing twin-turbos with ~130k (93 RX7). A lot of that relatively hard use at autocrosses in summer heat. I credit religious oil changes with synthetic and a little closer intervals with stock dual oil coolers.
And while common, if you hear coolant boiling it’s probably more of a sign you still have air in the system.