MX5 Donor

[trainer]

the torsen diffs are much stronger(300bhp+) and more active but still a road diff the vlsd is ok if it still works only lasts 30k if used hard and won't take more than 200bhp

they come in 3 different ratios 4.30:1 this is standard 1.6 and vlsd also the very rare torsen from a 99 sport with a 5 speed gearbox
And 4.10:1 ratio for 1.8 cars and all other torsens no vlsd
And 3.909 for the 6 speed gearbox

the six speed ratio is a no no you will go know where unless you get a 6 speed box its the same size

so its between the others 4.30:1 will give the best acceleration
however most of the turbo cars go for the longer ratio of the 4.10:1
maybe in a lighter car the longer ratio ie the 1.8 diff with the 1.6 engine

you can buy or source other sized ring and pinions that fit the diff from other mazdas!
i would go for the 1.8 torsen you will need the prop and drive shafts also
they come at a cost i paid £400 pounds for mine complete with shafts and uprights
or stick with what you got until you break it didn't take me long to break my vlsd