Originally Posted by c4s335i
$4k sounds a bit much for a differential. The stock m3 lsd diff is under $2k, and it's a clutch type.
OS Giken makes 2 types of diffs: regular LSD and Superlock (which is what I'll be getting). I have welded ring gear. I am purchasing the whole final drive unit. So it comes around $4K before installation in my car.
Is it expensive: yes of course it is. I spent the same about amount on power mods and I have FBO
Is it worth it: yes, most definitely.