i wouldn't hold your breath. there probably isn't enough demand to make these gears for the rx8. you would have to change at least the drive and the driven 6th gears. just to give you a for-instance...

the 5/6 gears for the T-56 (which is used in a TON of cars... 93+ camaro/firebird, viper, corvette, cobra, gto, etc...) are $995.00 for the set of four, and that is a much higher production volume.

as others have said, you could change your FD ratio, but then a slow car will become even slower.

 

Shift to 7th.

 

easy answer: shift sooner, drive slower.
that really is the only way

 

because the AT diff is a 4.3 and the MT is a 4.44 which would drop your revs by 130 rpm at 80 mph (4000 rpm)

you could probably pick up an AT diff pretty cheap from a wrecker as there would not be much demand for them .......

 

I have wondered about using the FD automatic 3.9 rearend. They look VERY similar, and I have heard it reported that rx-8 diff gears are the same dimension/fitment wise as FD gears.

Does anyone know if the speedometer reading is driven by the transmission/driveshaft rotation rate, or the ABS/wheel sensor reading? I would imagine the latter, which would give us freedom to experiment with alternate gear ratios without throwing off the speedo.

 

the latter,

and mazmart has offered 4.1 and 3.90 gearing.. the changing of the 5th 6th gear set is being talked about..

beers

 

yeah, even with the big jump to 3.90, it only drops the 80mph cruising rpm by 500 or so, which isn't going to save a whole shitload of gas.

I found it odd that I was cruising at 100 on the interstate for a few miles and looked down to see my tach sitting damn near 5000rpm.

 

changing gears is one way, but the correct way.

but to lower revs some, i'm sure getting some 20s or taller tires will do the trick. just expect the car to be slower.

i did the exact opposite to attain fatter, wider, lighter tires.

 

If the 7th gear doesnt work for you, I'll throw in the 8th gear for free.

 

^^^ I'd like a 2nd gear for reverse plz.