Does the Savvy mid arm use the stock axle LCA mounts? It seems like most serious builds mount the rear axle LCA mounts on the front of the axle tube for clearance, but does it also improve geometry on 4" and up lifted Jeeps? How would the Jeep act with that mod?
Yes, for a few reasons but mostly because it works better there and changing it add a layer of complexity that isn't worth it.
I was surprised to see the frame mount with a near vertical leading edge. Some plate and a welder would help that.
The TJ has a bend in the frame right where the front edge of the rear mount goes. Ideally, the mount would like to be about 2" forward but that really complicates the design of the mount trying to make it fit in a bend and keep the manufacturing cost down. That also puts the front edge of the reinforcing side plates that form the mount more vertical than would be ideal if you had the luxury of unlimited space.
It hurts more feelings than it does performance. In areas where clearance is a premium, a ramped front edge really works no better. A good example of that is in lots of places in JV if you wind up with too much weight on a flat belly side, it won't go. No ramp, just a flat surface that should slide and it won't if the weight on that spot is higher than the traction being made to move the rig. The other way to look at it is if you built a ramped front edge, then there is the risk that the ramp being longer will get in trouble sooner because the footprint is longer and it gets in trouble faster.
I think Nate and just about anyone else thinks their own designs are sound. As flat as his lowers are they probably slide over rocks easier than the mid arm which appear to have more pitch.
I promise you that Nate has not tested back to back designs in a race application, a winning race application at that. The mid arm is based on many iterations of what does and doesn't work to make a rig climb, make a rig be stable under all conditions and handle well. He hasn't stood at the base of the waterfall on Wrecking Ball time after time and watched how rigs climb it and then built a TJ with a mid arm and watched it scoot right up the fall like it wasn't even there. Designs with arms at the front of the axle tube were tested, we know what that does and it's nothing good.
I would bet the longer arm have more grind marks though. The proof is in the pudding though. It is not too hard to find vids that have him wheelin all over, including Johnson Valley. It seems to do pretty well. The RoadtoSEMA vids are pretty easy to find.
For those that haven't been there, JV is a funny place. My helper and his brother took a buddy of theirs through Sunbonnet a few weeks ago. Buddy is on 33's. It was a very long day. They spent a lot of time stacking, tugging and winching to get him through. I wouldn't have done it, I don't want to work that hard to go wheeling. But, the buddy can now say he has run JV. The proof in the pudding is running JV through the difficult spots without getting out to winch or stack and until you spend some time there, it is hard to fathom how that defines the levels of performance a JV capable rig does and doesn't have.
You can run Sledge many times in a row and think you done good. Then I ask if you took the sandhill exit and shorted the trail or did you turn left and finish the trail? The first fall after the left turn can be done by a TJ on 35's, if your rig works perfectly, you know how to drive, and you don't miss the line. A 1% deficiency among any of those and you'll spend 1/2 hour or more flailing about and get denied. Point being you can run JV but can you run JV?