diff knowledge
 

Looking for some knowledge on differentials, gear ratios, etc for drift. I currently have a 87 gxl with the clutch type lsd. Got my hands on a 88 open diff from an auto vert. I believe my current is a 4.10 gear ratio and auto has 3.9. Is there a noticeable difference? Also it is better to just shim the clutch type diff or weld the open diff? My car is basically stock, suspension is upgraded, coils, solid subframe bushings, mod knuckles, etc. the clutch type is in good working order but since I currently have it out of the car just would like to weigh my options before I put one of them in. Any help I'd greatly appreciate.

a shimmed stock clutch type is probably going to be better than a welded diff. a welded diff won't turn at all and will understeer everywhere except when you throw it into stuff. not ideal.

a 3.9 sucks, it'll make the car slower to accelerate. (this is why GTUs have 4.3s)

Now for shimming I've read a few different methods. One being add an extra clutch plate, not sure if its one on each side, and then put it back together. Also the whole aluminum can cut out as well but I'm not sure how to go about that route. Is it one cut out for every clutch plate? In between a clutch plate or only on the outside? How many on the outside? In terms of drifting now would a 4.3 ratio be more ideal for an n/a car? I'm assuming it'll make car accelerate quicker?

Look in here:
http://store.mazdamotorsports.com/pd...Drivetrain.pdf

It explains the gearing, basically it gives the engine more mechanical advantage over the engine so it can accelerate faster (2nd gear becomes like 1.9th gear if that makes sense?)

you can see on page D-10 #12 is a thrust washer which squishes the plates together more, you add aluminum can material to make the washer thicker without having to buy oversized washers. this just allows the diff to lock up tighter.

Thanks I appreciate the knowledge man. This really helps me out alot!