Twin I beam style suspension for a lightweight open front wheel car?

For my next build I'm kicking around the idea of using a front suspension based on Ford's twin I beam truck suspension. This suspension has a few drawbacks. It doesn't have ideal geometry. The biggest one, in my opinion, is that it produces large changes in camber with moderate suspension travel. Also, the way Ford did it, it is pretty heavy. Of course that's as applied to pick up trucks. I would be hoping to build a car that came in at around 1500 pounds with open front wheels. I'm thinking since a performance, relatively stiffly sprung street car doesn't have much travel anyway (less than 2 inches of commonly used travel) that the camber change won't be much. Doesn't A 4 bar chain (i.e., double a arm) suspension essentially acts like a long arm of the same type but with it's pivot way beyond the opposite tire?

I'm thinking this suspension could actually be pretty light. Hopefully lighter than the total of a double a arm setup. I'd put coil overs right above the wheels, next to the grille shell. I think that would look cool. Heim joints for everything. I'd fabricate the suspension arms out sheet, going for a constant stress, tapered approach.

Other options I'm considering are a Miata front end or a front end from a 90's Lexus SC300/400. Those are pretty amazing. Aluminum upper an lower a arms and even the sub frame itself is aluminum. I think one of these would look pretty exposed in the front.

I need to do some estimating with the i beam-ish system but then weigh the other two and compare. BTW, I would probably use the spindles from an old Toyota pickup or an E36 for the i beam setup. They both look like good options.

Here is a site with some twin I-beam setups on street rods, might give you some ideas.

http://www.hotrodders.com/scratch-built/Chassis:_Front_Suspension

Have a look at the early Lotus sports racers, Allards and basically any of the early 750 Formula cars. All used a swing arm style of suspension and worked reasonably well, but that was back in the early 50's. With limited suspension travel it might work, then again some people have had success with solid front axles.

Also, have a look into Mallock U2's, they have almost exactly what you're describing.

I'm not sure if I believe that it'll be any lighter than double A arms, but packaging could be even tighter than macstruts.

not sure how wide your looking for but 03+ crown vic front subframes are all self contained, could be narrowed too if need be to fit better into your application.

Have you considered using longitudinal torsion bars?

I can't see a sprint car style straight axle being worse than the twin I beam. A tube, three or four locating links and a couple small coil overs and you're done.

edizzle89 wrote: not sure how wide your looking for but 03+ crown vic front subframes are all self contained, could be narrowed too if need be to fit better into your application.

That looks pretty sweet! Looks like an aluminum subframe and aluminum lowers. Is that a forged steel upper? I think the sc300 one looks better bare. It's already setup as a coil over and has a nice looking upper.