Project RX-7

So i thought I'd kick start this blog with a little suspension talk.
Thankfully there are a lot of suspension options for the FD, thanks to, by a large degree, the tuners who run the car in touge battles and GT racing.
Fortunately or not, most aftermarket setups tend to be quite hard. While RE-Amemiya and FEED run their cars with 18kg/mm Swift springs front and rear, the other "mild" sport coilover options range from 16kg/mm to 7.4 at the front, 5.8 at the rear.

There is a wealth of suspension information available at FD3S.net with some useful testimonials on daily driven setups.

However (aaah, thought it was that easy did you?)

Seeing that PRX7 will pretty much be a dual purpose commuter weekend racer car, my doubts were as to whether or not a single setup "sweet spot" was appropriate. On top of that, the other recurring questions were: how do the OEM's do it? and is there a way to make the car soak up the bumps and still corner properly? Must... seek... answers....

To this end i had a conversation with esteemed colleague and fellow blogger deamoncynos7 about using harder anti roll bars and softer springs. The theory behind my idea would be using the anti roll bars to sustain some of the axial loading during cornering, while keeping a streetable suspension stiffness for badly paved roads etc.
We both agreed that harder anti roll bars would reduce suspension travel, which can be a problem over bumps. However this could be solved with appropriate rebound valving adjustments. Also, harder bars would oppose the weight transfer during cornering, which can lead to some "interesting" results when pushed hard.

Plan B would be to use a system like the EDFC or the equivalent by Tanabe to electronically adjust damping force with a push of a button. hard when you wanna go, soft when you wanna show, if that's your thing.
I see why it could be useful, but, the truth is that even though there is more than one correct damper/spring setting, having 12kg springs on the softest damper setting wont solve the ride harshness problem. The car will still crash over the bump, regardless of how well damped the crash is.
I'll be giving the subject some extra thought over the next few days, and hopefully run some numbers on some suspension diagrams. Suspension settings are a black art.