The stock US 2wd trans is a G50/20, stock RoW is G50/21, there are 3 RS trans, M002 RS uses G50/31, M003 RS/CS uses G50/32 and there is a Swiss. RS G50/33
n/a AWD versions use G64/20US, G64/21RoW
turbo uses G64/51
993 Cup used G50/30
The /30, /31, /33, /32 used in the Cup, RS and RS/CS have steel rather than brass syncros, the /30, /31 further have reinforced syncros and steel shift forks(others use al.)
here is a comparison of speed vs rpm and gear
At first glance they don't appear to be that different but in actual use they are night and day
here is a comparison of trans.
In a sporting trans you are looking for decreasing split % is you go up through the gears. You start w/ the highest top speed you want and work backward. For me and the tracks around here that would be ~160.
While even the /30 is great for street use, some may prefer 6 to be taller for fuel economy and more relaxed cruise. But stock is still too high. Notice the 2000rpm cruise speed in 6 of 56mph. You can barely get into 6 at freeway speeds w/ a stock box and stock 3.6.
In these you can see the drops, stock /20 has a particularly huge drop 1 to 2, and then still large ones for the rest.
The longer you can stay in the 1000 rpm sweet spot of the rev range the more responsive the vehicle will be.
The /51 turbo box is a /20 w/ beefed up bearings and much taller gearing, it has large even drops, more appropriate for an ultra torquey turbo street engine, but not for sporting use.
