mazda miata gear box 13b tranny

[Nopis1O]

has anyone done a mazda miata gears in a 13b tranny. i heard you take the miata tail shaft and gear box and use the housing of the 13btranny. i know its possible but i just wanted to know if anyone in this form has done it. i am going na and just trying to pick up a little more acceleration in second gear for autocrosssing.

thanks

[Nopis1O]

pics of the build. performance gains? how it seems to hold up? i have talk to rx7girl on nopiston.com just wanted a couple more opoions. thanks guys

[djmtsu]

It has been done, and there is not real benefit. There is a considerable amount of work to be done (input shaft needs to be modified and resplined for instance).

Changing the differential (a GTUs 4.33 gear ratio) is a good idea, and easier.

[Nopis1O]

i just need a shorter 2nd gear for auto crossing. that sounds better because that wouldnt bump me into prepared so i might just try that.