I know some people are interested in this.
I called SpeedSource
about getting the MazdaComp
ring and pinon 4.875 fitted to the N/A LSD rear end.
They said $375 to lengthen gears to fit and then you have to install them in the rear end. I guess you have to load it right and a bunch of other stuff over my head to make sure they don't blow up, so I asked how much if we just send the entire pumpkin to you and have you install the gears into the rear end. Thats another $150. Plus parts to rebuild the entire rear diff, he said when it's all said and done 5.12's cost a customer around $600, excluding the cost of the gears.
The cost of the 4.875's from mazdacomp is $281.40
While the cost of the 5.12's are $561.65
Hmm...decision's decisions, personally going with the 4.8's sounds pretty cost effective, basically 800 bucks for the whole shot...It would be better if I knew how to rebuild and install the gears into a rear end, I wonder how hard it'd be. Because for $656 thats a decent deal, when the 4.33's are 500 alone from racing beat.
I wonder how useless 1st gear would be in the stock N/A tranny?
RING AND PINION, 4.875
Short pinion design. Fits 79-85 RX-7, 1994-01 Miata, RX-2, and RX-3 SP. Can also be lengthened to fit 86-91 RX-7 non turbo.