ok , i have two questions ...
1. what is the shutter valves perpose ??
1.5. can it be removed ??
2. what is that gold sticker on the drivers side quarter glass i keep seeing ?
2.5, why is it there ??
thats actually kinda like ... 4 questions ........

 

Ill leave the shutter valves to someone else, but that gold sticker is some "Mazda seal of coolness" thing. I believe it came from the factory, mine says something about 1981 - 1984 excellence.

wow...im not much help at all!!

 

The IMSA GTU sticker represented the car's race heritage.The 1G RX-7's pretty much cleaned house every year in IMSA GTU racing.Each year,the gold sticker had another championship year represented on it,until 1985 when it was pretty much full.They didnt continue the tradition with the 2nd gen,but they did offer a lightweight,sporty N/A model called the GTU.

The shutter valve is designed to shut off fuel flow to the rear rotor under decel.It works in conjunction with another valve on the intake which routes air only to the rear rotor whenever the shutter is closed.Its to keep the surging and bucking at bay during decel, and an EFI equivelent was also used on all later RX-7s.
Apparantly,there is an issue with rotaries when under decel which required the system.Its not 100% needed,you can remove it,the 79-80 cars didnt have the shutter,and the worst side effect might be a little buck as you slow down with the clutch out.

 

Thank you guys, helped out a bunch.

 

Shutter valve causes stalling and constant throttle problems, car jerks and bucks, I blocked mine and solved the problem.

 

I have always wondered if, between the shutter valve on the carbs, and fuel cut on the FIs, if these aren't the major reasons that the rear apex seals fail more often, or if it is simply the coolant is taxed by the time it gets to the rear rotor.

Food for thought.

 

Most of the engines I've seen had more missing chrome on the front rotor housings than the rear. The year spread was '74 through '85. The front rotor housings consistantly had more wear regardless of whether the manifold had a shutter valve or not.

 

Any ideas on why this seems to be?

 

Its gone back and forth on the FC sites too.

Some say its because on TII's,fuel cut happens on the rear rotor.....but then that would leave the front rotor struggling to drag the engine around,making that chamber more likely to go pop.

Others have said that the intake manifolds run naturally lean to the back rotors.Indeed,the TII manifolds are not perfectly symetric if you examine the runners.I seem to remeber something about uneven airflow into the rotary when reading the old rotary engine design book,written by THE MAN himself.

Who knows?.............