Jim - got your email - I'll give you a call to chat
Spent the day in the shop trying to get some forward progress
weights of the diffs
s2000 without stub axles weighs just shy of 60 lbs
open-diff miata diff weighs 62lbs and change
putting a limited slip in the miata would add a few lbs - the stronger s2k diff is the clear winner for the weight.
the complication comes down to the axles - the miata inner and outers aren't compatible at all with the s2000 parts. I'm going to talk to dutchmen in town about sticking the miata outer CVs on shortened s2000 axles because I really like using the miata outer spindles/hubs.
I then went onto sticking the engine in the bay to see what changes were needed.
before any modification this is as far back as the package would go
the fitment was tight at the bellhousing - the s2k trans has a HUGE bellhousing in comparison to other common options
the bottom frame tie-ins didn't fit at all so I had to knock them out - you can see them hitting hte oil pan even when it was high
I ground the bottom of the trans fins down to help bottom clearance and ended up knocking part of the top bar out to get the bellhousing farther back
that put the shifter back right where I wanted it and left the engine about as far back as it can comfortably go in the bay.
bellhousing bottom fitment
that leaves the oil pan sitting about an inch below the frame which is lower than I would have liked but the engine is just so damn tall...
In comparing the height of the engine and fitment with the hood/nosecone it leads me back to again considering going drysump... I was hoping to put it off for the time being to parlay the costs to down the road but I don't want ~2 inches of engine sticking out of the hood getting in the way of my vision.
I need to get some more accurate measurements with the bellhousing fins all cleaned up and the engine sitting exactly where I want it rather than closer to get a good understanding if I can put it off for now.
I put the hoist away and propped the setup in the chassis on some 2x4s and left it there to admire how damn tall it is
I think I'm going to pick up a set of these http://www.speedwaymotors.com/Rod-End-B ... ,1583.html
(very locost in comparison to the other similar options) to use for the rear lower outboard mounts to the spindles (similar to how mattrogers did his minus the energy suspension parts costs) and just get the correct size DOM tubing locally - I think they'll also make good engine/trans mounts as well and a single set should do both the rear lowers and 3 engine & trans mounts.
the rear miata spindle upper bushing housing ID is spot on 1.5" in diameter and 1.85" wide - according to http://www.suspension.com/4-bar.htm
I can pickup a pair of #9.9483 and trim them down a bit in width and run 1/2" bolts with ease.