I am looking for 400F 450R that is 100 less then Andy Hollis. My friend has the ford racing auto x kit and he said its pretty good but I still want better rates. I will be waiting on koni yellows and then I will start to really look for springs
EDIT sorry I mixed up the rates. He ran 550F and 500R so I would want 450F and 400R. Also after talking to another friend I am going with these. Aleady called them company and they will do anything you want no extra charge. I will be upgrading to swift springs as well for $350
http://www.fortune-auto.net/fortune510seriescoilover.htm
Joe, if your girlfriend didn't like the catback, she's going to absolutely hate you for putting springs like that on your car.
You are contemplating the setup I used for autocrossing on smooth concrete. It is a PITA on the street. Sure, I drove it that way on the street, but if you have any kinds of bumps in the road, you are going to feel it big time. Remember, this is a strut car, so the motion ratio is 1:1. Which means the spring rate is the actual wheel rate. By comparison, something like an NA/NB Miata is double a-arm and the wheel rate is approximately half the spring rate. Note that the Spec Miata racing kits use 700/350. That's for a pure racing car on r-comps. Divide that in half and you can see how aggressive my autocross setup was.
I ran them that stiff for several related reasons:
1) Front roll control w/o changing the front sway bar. This is critical to the car's handling. Due to being a strut, it has no camber change curve, so dynamic camber in the turn is everything. Controlling the roll reduces that dynamic camber w/o excessive static negative camber (which causes wheelspin and crappy braking).
2) Lowering the car. This reduces weight transfer which has two benefits: a) less body roll, which means less dynamic camber, and b) more efficient use of *both* front tires. Outside tire is not as loaded. But lots of lowering means lots of spring rate to keep the car off the bumpstops. In autocross trim, my car was lowered on the order of 3 inches.
Even with all of this, I ran 3 degrees of static negative camber, which made braking a challenge and wheelspin inevitable on slicker surfaces.
Once you set the front up, you need to balance it at the rear to keep the car neutral. Big rear bar is a must (Racing Beat is the biggest). I then used different rear springs to get the rotation I wanted on different surfaces. The 500's were for grippy concrete. For slicker asphalt, I swapped in the front springs from the K-Sport package which are 280. Otherwise, the car was too loose. For rain, I would swap in the K-Sport rear springs, which are 168...otherwise, the car would swap ends easily.
Once you have springs in these realms, you need dampers that can handle them. The K Sport fronts cranked to full stiff will just barely damp the 550's. They really could have used more bump damping, though. The rear custom AST's were magic and transformed the car versus the rear K Sport. Cannot recommend them enough for autocross.
But that is all no-holds-barred autocross. When I retired the car from competition, I backed off in steps to get a daily driving experience that I liked. I travel a nice twisty canyon road every day, so I like something that handles well, but not something that is so stiff that it juggles your innards over every little road undulation. Another side-effect is that the DSC was constantly kicking in because the bumps were driving the internal accelerometers crazy, so I would have to turn off the DSC to keep it from intruding all the time.
Step 1 was to go back to the K sport standard rear springs (168). That was a huge step, but now they were overdamped, so I swapped out the AST rears for the K sports. That helped a TON. Car was infinitely more driveable on the street, yet could still be thrown into a corner at ridiculous speeds even on the OE tires. Note that I also raised the car back up to about 1.5" drop from stock, and set the front camber at 1 degree. DSC was much happier and the car would not swap ends in the rain. It was still rough over bumps, though, and had nasty wheelspin in/out of driveways and such. Not enough front travel, basically.
At this point, my wife would still not drive the car, though, and often would not even ride in it. So I recently took the next step and put the K Sport front springs on the front (280). Adjusted the shocks to about the mid-point at the same time. That's what I've been running for a couple of weeks now and it is perfect. Together with zero toe, 1 degree of camber and a 1.5" total drop, the car handles great and rides decent. Car also still has the whiteline lower control arm bushing with extra caster (big one) and the powerflex lower rotational bushing. Those help keep road feel and precision. RB rear bar keeps it neutral and flatter.
The last step gave up a little bit of handling in exchange for optimal street manners, but the car is still stupid fast around turns and well-balanced. I would not recommend anything higher than those rates (280/168) for a street-driven car, unless you care more about very serious autocross or track use.
BTW, AST now has a production style front and rear damper set available. I'm getting more info and will post up a thread when I get it.
PS: Joe,
here's a pic of how I made the rear springs work. These are the K Sport ride height adjuster with a little modifications. They are designed for a 60mm id spring, which is close to a 2.25". I used 2.50->2.25 adapters until I later got some 2.25" id springs. Check out my posts in that thread for more ideas on how I did stuff. Camber bolts are a better front solution than slotting, though.
