1. Should I tighten the top nut with an impact? I don't see another way, but with the nylon washer in the top nut, I'm worried about it spinning the shaft, and there is no way to hold the shaft with the adjustment on the top.
2. What spring preload should I use? It looks like for a sports car coilover, zero preload is mostly recommended unless you have problems after install. Anyone have any suggestions for the SHO?
3. Where do I even start with height adjustment? Just put them in as they are, get the car back on the ground and then figure out where I need to go from there?
4. Sway bar preload. Not sure what the best adjustment is for the sway bars either. Do I try and keep the stock placement?
I will do my best to help. These answers are based on my experience running the original prototype SHO Source coilovers as a daily driver for approximately 40,000 miles and my experiences on our purpose built RX7 race car with coilovers.
1) I agree you should not let the shaft spin uncontrollably when tightening the nut. I personally use a rubber strap wrench wrapped around the chrome shaft (as high as possible). This usually lets me get acceptable torque on the nut. An impact with short blips will do it, but it is way to easy to overtorque the nut unless you have really good torque sticks, so I usually avoid an impact gun.
2) My best result for preload was one turn on the collar past zero preload. This has the advantage of giving you full spring travel, while holding the assembly together tight enough it won't jump out of the perch when you jack up the wheels or lift one in hard cornering.
3) For height, I tried to stay close to the height of a car on lowering springs. We had some customers that went as low as they could go, and it still worked for them, but I hated scraping the air dam on speed bumps. Unless you are corner weighting the car, make sure you measure to keep your left and right side on each end the same. Front to rear can vary to set stance, but left and right on each end should stay balanced. I you are corner weighting, or at least have a set of scales, all this goes out the window. Corner weighting is a science all its own and needs its own thread for sure. As an aside, I did run the suspension higher than stock during some winter snow driving. It looked ridiculous, but I was able to drive through deeper snow.
4) I have always been taught to keep the swaybay neutral at rest. Some people play with preload in corner weighting, but my best results were from adjusting ride height with the swaybars disconnected. Once my corner weighting and ride height is set, I will reconnect the swaybars with no preload. Since you get adjustability here over stock, you can finally adjust the swaybars to horizontal when the car is sitting at rest. Keeping the swaybars horizontal puts them in the middle of their range of motion and installing them neutral keeps you from having hidden preload.
5) Sway bars are another long discussion. Without coilovers, my personal preference on the Gen1 or Gen2 was 24/26 (or 22/26 with a Quaife). With coilovers (and the stiffer springs), I have seen people stick with 24/26, but I found that to be a little too stiff. I have also seen people delete the front bar and only go with a 19mm rear, but usually those cars had much stiffer springs on the coilovers. I hate to say it, but you may have to be prepared to experiment with swaybar sizes. Keep in mind, too much front swaybar will make the car understeer or push (you try to turn into a corner but the front wheels tend to slide). This is the safer condition for most street drivers. Too much rear sway bar, and the car tends to oversteer (the back end comes around and you spin). This is how race drivers like it, but it can be dangerous on the street. Be careful as you feel out the new suspension, and please let everyone know what swaybar combination works best for you (assuming you are on the standard coilover springs we ship).
6) Make sure you periodically check the tightness of your end link mounts and rear mount lock collars on the coil overs. They tend to want to rotate as you turn the car. I cut into the inside tire on the prototype car until I got it locked down. For extra safety, I cut off and ground part of the upper end link stud so it did not stick out as far to give me a little more safety (I was running wide tires).
Please let me know if there is anything else I can do to help answer questions.
Mike
SHO Source
