The closest you might come to a cheap, available unit might be a 4.10 from an automatic. The next best thing would be a 4.30 from a GTUs. More rare, and more expensive. The manual trans cars came with a 3.90 almost exclusively, I think.
You got that backward Chris. The autos came with the 3.90s. The manuals the 4.10s.
Cool, then I've got two 4.10s sitting in my garage! I wonder if anyone has had any success running the S4-S5 as a 4-speed using a 4.10?
No performance numbers, since my car went through some other significant mods at the same time as the 4.10 -> 5.12 change. However, it changes your 2-3-4 shifts into 3-4-5 shifts. You need the close ratio transmission with the 5.12. I haven't done the math to decide if 2-3-4 with the 4.10 is better/worse than 3-4-5 with the 5.12. Might be track-dependent. I do know I don't like the shift to/from 5th.Cool, then I've got two 4.10s sitting in my garage! I wonder if anyone has had any success running the S4-S5 as a 4-speed using a 4.10?
I do know I don't like the shift to/from 5th.
Me? Yes. (in the car, not for sale)Do you still have the 5.13?
matt
The .756 5th gear is preferred over the standard .697 or .711 - the .756 is only found in the GTUs (not to be confused with the GTU) which are very rare, in most cases you need to get the .756 from Mazdaspeed and have 5th gear replaced when doing the rebuild. Not sure what you have, but this may help the problem.
Of course there are the Miata tranny gears, but NOT LEGAL for IT.
I used to have a gear calculator that would allow the plugging in of ratios and spitting out of speed/rpm tables. Don't remember where I got it though.