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I essentially already posted this in the 2nd gen section and got no response. I am thinking that the 1st gen posters are more knowledgeable about this kind of thing so reposting with a few modifications here. I hope that doesn't violate any forum guidelines.
I am wondering if anyone has experience installing the NB Miata shifter block and side plate (circled in red in the attached sketches) in an FC transmission, replacing the parts circled in blue)? I am thinking that it would have to be an FC transmission, because as far as I can tell the FB shifter blocks are all held in place by a bolt rather than the roll pin that appears to be common to the Miata and FC. The point of this modification would be to eliminate the centering spring that was stock on the RX7 trannies. I heard about this over the weekend and just wanted to see if anyone else has done this. It looks like the shift rod diameter on the RX7 might be bigger in diameter than the NB? Although that might not be the case if using the NA Miata parts? Or maybe the NA Miata parts are the best to use? The NB shifter block has two wings, whereas the NA has a single wing like/similar to the RX7.
Any thoughts? Other than that I am maybe an annoying idiot.
You're probably breaking new ground here. I've only ever read about swapping 1st gen internals for Miata internals. Never read anything about the shifter block thingy.
I believe that the "return" spring (17-465C) that goes around the shifter block is no longer available. In my recent experience the springs also don't seem very strong even if not broken, resulting in not very positive shifting. I am hoping that the Miata spring on the side of the housing will be more positive. To say nothing about easier to replace ;-) This is for a friend's FC race car. The Mazdatrix short shifter in my FB has been great for 20 years.
I think we have all the parts available so need to dig them up and see if it will work. Just thought I would check around first to see if it is clearly a waste of time.
I use the Miata turret with the 2 centering plungers on my 82 FB transmission. It was a few years ago, I think I might have had to shorten the tube, or redrill something. I also had to hammer a divot into the tunnel sheet metal for clearance. It makes the shifter feel better, and I won't have to worry about the spring breaking
I believe that the "return" spring (17-465C) that goes around the shifter block is no longer available. In my recent experience the springs also don't seem very strong even if not broken, resulting in not very positive shifting. I am hoping that the Miata spring on the side of the housing will be more positive. To say nothing about easier to replace ;-) This is for a friend's FC race car. The Mazdatrix short shifter in my FB has been great for 20 years.
I think we have all the parts available so need to dig them up and see if it will work. Just thought I would check around first to see if it is clearly a waste of time.
Carl
Hey Carl,
If you didn't get this swap figured out, the return spring is available. Atkins Rotory is reproducing them.
