Final drive ratio questions
 

Hi all although im breaking my impreza i actually have another subaru that im building a justy (suzuki swift ) ! ha. But it

the justys weak link is the rear differential being small and open centre

the final drive on the justy is 3.416

impreza one ive seen is 3.511 ?

there is also a bmw diff ive found that is 3.45 ratio

my question is to any drivetrain gurus out there how much tolerance is there beetween the two?.

one guy has used a impreza rear diff but had to use different tyre profiles to balance out the rotational difference im not a fan of that personally as it limits tyre and wheel choice.


the bmw diff works out 0.04 of a rotation of difference does that increase with speed ?

only other thing i have considered is getting a custom final drive made for the subaru rear diff to 3.416/3.41 but not even sure who to ask about that


all advice appreciated

thank you