I ordered up every bushing, ball joint, tie rod and steering component imaginable. for front and rear. The rear had just had a refresher and therefore most of those bushings stay.
I want the car borderline too stiff for road based suspension. I don't drive the car daily, and when I do drive it, I prefer it be more on the aggressive side. Having had some experience in setting up road race car suspensions I decided to get down to math.
Our dual a-arm front suspension is fairly easy to calculate and create (theoretically) suspension for, its the dampening that I am worrying about. Here are some numbers I put together for my spring rates. Yes I know this is aggressive, worst case I order some softer springs.... no I take that back worse case I break something.
Corner Weights:
FD 570
FP 550
RD 560
RP 540
Total: 2220
It is important to note that these weights are estimates, and real corner weighting will be whatever I decide once adjustable suspension is affixed to the car. These numbers are just for rough calculation. The car has no bumpers, 2.5in lightweight exhaust/header. No rear seats, no stereo, no insulation.
Unsprung Weight:
Rims 14" BBS 11lb
Tire Azenis rt-615 19lb
Big Vented Rotors 8lb
Brake Caliper 7lb
Knuckle and Hardware 8lb
Control Arms 8
Total: 61lb
This puts me at a sprung weight of 509lbs, and springs which are 375lb, but end up with our suspensions motion ratio of 1.46:1 to be 240lb coil rate.
The numbers end up with a wheel frequency of about 105 cpm. This is without my wife and I in the car. This is about the same wheel frequency of a S2000, or a Miata with upgraded suspension.
I stole this idea from Halg, but decided to go a different route due to valving concerns. He used the GM package likely for the lower spring rate, and more stock shock stroke. I decided on using the QA1 Mustang kit:
http://store.summitracing.com/partdetai ... toview=sku
I felt the dampening was going to be a bigger concern to me than the spring rate, as springs are cheap to buy for coilover suspension. Both use upper body mounts, and both use rod style tops. The Mustang system costs $50 more has a higher spring rate and is adjustable in the way of tied comp/rebound. I knew that out back I was likely going to go with a different brand rear shock so I wanted to be able to match the valving based on the provided dyno sheets for both shocks.
Now the only concern being the stroke of the mustang kit. It is about an inch less than stock. I find this almost good because the car will be lowered more than 1 inch below stock, so I look at the travel as being potential more useful travel.
So that's the front... how about the rear?
I happened to have a set of bilstein sport shocks from a BMW e30 which btw are a direct boltup to our fiats. I do not yet have a dyno chart for this shock, but will be able to get one and match valving fairly close to the qa1 setup up front. Spring rate in the rear was calculated in the same method, but with a different motion ratio.. 1:1 to be exact. A sprung weight of much higher as that axle has to bounce around. Here is where the numbers landed
Sprung Weight of 410lbs
Effective coil rate of 150lbs
Gives me a Wheel frequency of 110cpm
Once again these calculations will change in a the direction of more compliant with 2 people in the car, and a full tank of gas, and maybe that roll bar I keep wanting
I went with a higher rate in the rear to induce more oversteer, and make sure I had a good frequency differentiation between front and rear. No one likes resonance in a system So how will this car stop?
Once again Halg seems to have pioneered this system. A friend had some 1999 Civic Si brake calipers sitting around which I was going to use, until I saw them in person. They were rusted, but would make a good core. So I picked up an entire front brake system rotors, pads and calipers for $150 from Autozone. The quality of the rotor, and pads is questionable, but I figured I could upgrade those to aluminum top hat designed rotors in the future, after the system has been proven.
I designed up a caliper adapter which if Halg doesn't produce I will. I will likely also sell a rotor with a top had pre drilled for 4X98 with hubcentric ring adapter.
Why not just go Whoa?
It is my belief that a braking system is only what it can transfer in the way of heat. The clamping force of the civic Si piston I felt was not only adequate, a slight improvement over stock, but within the master cylinders reach. The big improvement I feel is the move to 260mm vented rotors, and pin/bushing style caliper design.
Building a Wilwood based system would have left me in the unvented territory, and for a 1200lb sports racer I love non vented rotors, and have great luck with setups like that, but for commuter/racer which has to carry my sorry self around, I chose the heavier, larger, vented rotor from the Honda. I also like the availability of pads/rotors at a moments notice.... err a moment and the machining of a 4X98 pattern
In the rear I went with stock brakes. I decided this was a good move for now, maybe later I will feel the need. Ohh before I forget and get flamed, yes stainless lines all around
Current state?
All the suspension front and rear has been removed, and is awaiting my lazy self to either blast or powder coat. I will take pictures and update everyone as the project goes forward.
I also want to note that, I don't have all the answers, and this is a project. If my calculations are wrong, then I make note, and try again. When its completed I might come back with a completely different spring rate, and find my brake bias is wrong and requires some sort of adjustment (which btw will likely be handled by some sort of adjustment nob mounted in the interior attached to the stock bias unit, once I figure out how that thing works). This is ok with me, and I understand that I might have been able to do more calculations and do it perfectly the first time. I needed to take action, instead of talking to myself about what I might do for months on end only to find winter arrive.
So this is the path, and I'm not afraid to take a detour. Comments and questions welcome.. duh its a forum
Josh
p.s. Pics to come tonight...
The car did not come with a rear swaybar. What are you planning to use the car for? Just curious.
I forgot. I wont on the lowers. 
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