so i used the search feature and coulnt come up with anything specific that could answer my question so here it is

is there any difference between the 2? one stronger than the other. im looking at picking up probably a non turbo as a daily project/eventual drag project and i was just wondering if one was stronger than the other

 

Strengthwise they're pretty much the same. The limited-slip operation is quite different. S5's are viscous, S4's are clutch. For drag/etc, you'd probably want a S4 and rebuild the clutch packs.

 

ill probably build a spool or weld it. maybe ill go with a lsd but im not sure. its going to be subjected to a lot of n2o and some big stickies.

what tends to break on them? is it just the axels or is it the ring and pinion?