Brainstorming...what if the entire IFS assembly was mounted in a ridgid frame (along the lines of Atomic Axles), with the control arms fixed in position? Then the whole setup is coil sprung. Would allow a high-clearance front axle. There's something called a De Dion suspension that uses a beam axle and a separate drivetrain assembly, sort of like this.

I have never seen a de Dion on the front. The usual layout is the hubs connected by a rigid frame so they are always parallel, with a frame mounted diff and cv axles. Some form of hub location must be used to retain fore/aft hub location. The primary advantage is reduction of unsprung weight (the diff). There is a risk of overrunning the angle limit of the cv axles in an offroad vehicle.

If I understand you corresctly, you are spring mounting the whole IFS. You have a really large unsprung weight that way. I see no real advantage over sas, Now, if the original a arms were still functioning, you'd have more front travel, but would have to have some spring suspension on the a arms (coil overs?) and two sets of shocks, and on and on and on.

Since the existing Montero IFS already has the rigidly mounted differential, there's little to be gained as far as unsprung weight goes, which is the primary advantage of a DeDion suspension design. What I think you're suggesting is some sort of suspended subframe, which would increase the unsprung weight without any benefit to the suspension geometry or travel over a well-designed IFS.

If it's never been done by any auto manufacturer, there's probably a good reason - either the complexity or the expense of the design makes it unrealistic. Usually this means that better results can be obtained with a more commonly existing design. I'm not discouraging thinking outside the box, but when it comes to off-road suspensions, I don't think there are many possible designs that haven't already been tried. If you want the ultimate in an off-road suspension, look to the vehicles that are built to compete in whatever format you're thinking of using your vehicle for (rock-crawling, desert racing, rallying, etc). The winning vehicles in those arenas will have the best suspension designs for what they are trying to accomplish.

Like this? From here.

Do check out the Atomic Axles housing. I can't believe the price they want for it! Basically it's an inverted-Vee enclosing IFS-style CV axles, with D60 knuckles.

I'll have to view it at home, work blocks Photobucket.

Wow, that Yota has one crazy setup! I used to have one of those actually, an 89, but it was a 4x2. Very solid vans.

What I envisioned was sort of like that but the assembly would be rigid and suspended from springs.

Regarding the Toyota Van...what's the point? All the work needed for that, just put in a solid axle and be done. If you want this for lift alone, or ride quality, how about IFS like a desert racer? Otherwise I think I'm missing the point.

You aren't alone.

Seconded...