I live in a land where a stock 12A has 25% more effective torque; where I can drive an indicated 100mph in a posted 70mph section on the freeway without serious risk of a ticket or endangering others (indeed, I get passed a lot); where Portland and Seatte are now 232 miles apart, rather than the usual 186 miles, but still only take 2.5 hours to drive between. I have 4.875 (aka 4.88, rounded) Ring & Pinion gears. Interestingly, fuel economy seems about the same...

Seriously, I love 4.88s on any NA rotary, as they just "wake the car up". And, as indicated above, it can feel faster just by looking at the speedo.

 

That's a good one Blake!

My REPU's 4.625 is in a similar boat. On Freeway keeping up with flow of traffic 5th gear 4500rpms. zoom-zoom-zoom

 

I too have experienced the REPU side of things, and love it. I'm sure an NA 12A in a lighter vehicle with 4.88 would simply fly.

 

Is it possible to recalibrate the speedo after a ring/pinion change?

I'm lookin for a Torsen from a Miata for my 7...

Damn people and their open diffs.

 

Yeah, it makes the car feel much quicker. The weird thing, as I noted, is the speedo error when swapping from 3.909 gears. The last time I ran 4.875s on a 1st gen, it was a Peripheral Port 13B without a speedo, so this is kind of new to me...y'know, passing cops at an indicated 100mph, when you are really just pacing traffic at 10 over. It might take me a while to get used to that.

 

There are different RX-7 speedo gears (in the tranny tailshaft) available for ratios such as 3.9, 4.1 and 4.3. I suspect I might be able to use an early REPU speedo gear to get back in the ballpark, but it's not a high priority. I kind of like "speeding" safely.

 

Good luck with the speedo gear sets. Something tells me they may not be fully compatible.

 

I'm looking to buy a REPU speedo gear. Anyone selling?

(My REPU came with SA 5speed and speedo gear )