MacPherson Struts vs. Double A arms
 

why do people say double a arms are better than the strut suspensions? Is there any reason to use a strut over double a arms, besides space saving and cost?

thanks
Rip

I'm interested in this as well. Could some suspension experts shed some light on this subject?

In a nutshell it is impossible to generate camber gain as the car rolls with a strut suspension whereas with double a-arms you can.

With struts you set the camber to whatever you like and the tire pretty much just stays at that setting in relation to the body no matter how much the suspension moves. This means the tire footprint tends to lean away from the turn rather than stay flat, just as the car's body roll does. With an unequal length double a-arm type suspension the tire will gain negative camber as the suspension compresses. This keeps the foot print of the tire "flatter" as the car rolls and compresses the suspension. Usually the roll center location is more favorable with double a-arms as well.

Struts are inferior performers in every way compared to double a-arms with the exception of simplicity and costs.

^ So, now the question comes down to: has anyone made a stock unibody (i.e. not a full blown race car tube frame chassis, etc.) FC a long arm-short arm front suspension yet? IIRC, the FD is already a long arm-short arm setup stock, so I don't really care about them in this case.

Also, could you enlighten me as to what the rear suspension setup on the FD is? Is it a trailing arm or mcpherson setup?

EDIT: Nevermind about the second question, lookin at pictures, it looks to be a top a-arm with semi-trailing lower arm.

http://www.automotivearticles.com/Su...pensions.shtml

for anyone else looking

I plan on converting my FC to double a-arms. I hope to reuse the upright, and lower control arm. The custom parts will be an adapter that will use the top two bolt holes in the upright (where the bottom of the strut bolted in), and of course the upper a-arm. The inboard mount will be along the frame rail (with cross bracing to take the side loads).
The steering rack might have to move up/down to minimize bump steer, but I should still be able to use the stock unit.
Of course the front shock will have to be custom. I might be able to incorporate a stock sized shock off of another car (like a Miata rear shock). That should help with the cost.
This is all still preliminary. I need to get the FC chassis hardpoints into Solid Works so I can start working on the geometry.
I'm probably going to try something similar in the rear to get rid of the subframe and heavy trailing arms.