Ok so, basically my idea is to use tacoma strut assemblies for my 2000 Honda Passport. I'm tired of the crappy ride. I'm a engineering student so I got the skills. I want to know if I can convert my torsion suspended front suspension to coilovers. Couldn't I theoretically install a coilover on the shock mount, beefing up the lower shock mount and fabbing an upper mount. Would this still keep the same geometry? I might have to modify the upper a-arm to allow the coil to go through it. Does anyone know how to find out the spring rate of a tacoma strut assembly. And does anybody know how to get plans for my truck. I'm really good at 3D design and if I could model my truck, It would make it easier. Thanks for the help and opinions.  

Your not the only one looking for a coil over conversion, I've been looking on ways to get rid of my torsion bars, in favor of ANYTHING but torsion bars or a solid axle conversion. I've tried going that route for mounting it to a shock mount on the frame, wont work, not strong enough. Best idea, build your own upper a-arms and make a shock hoop, run a bar over the engine connecting each shock hoop just for strength and rigidity, you can probably run dirt logic 2.5 coil overs or build your own using summit materials for like a quarter of the cost.

Only problem, no one has even tried building one, although fabtech does a pretty cool a-arm setup for only 2 shocks, for the 99 through 06 silverado maybe it'll help you get some ideas for a similar setup. I dont know how much room is under a passport though. Good luck and btw I'm also an engineering student at VT, if you get anywhere with that let me know.  

A big problem that you are going to run into with a vehicle that is not designed for coilovers is the upper arm to coilover clearance. It just simple may not be there.

If you do do it, would go with a custom hoop and like a set of 2.0 SAW (or similar) coilover instead of trying to jury rig stock parts off of another truck to fit.  

I think it is too much trouble.  I would buy a vehicle with coils already in place.  

yea the hoop clearance is a problem, but if u got the time and know-how it's a hell of a lot cheaper than buying a new truck. Plus you gotta make sure the a-arms can handle the forces of a coil over, I know my truck wont, which means building a set of upper and lower control arms.

The problem with those hoops, unless they're perfectly vertical from the frame they will cause an outward twisting motion on the frame and if your frame isn't boxed, you're looking at alot of damage from just the weight of the truck. Hence that's what the cross over brace is for. Plus it just looks cool.