^Wow, that's outstanding. I wish I'd seen that earlier. I guess I'll be going with the Super Pro bushings when I finally do the fronts!


As for the suspension setup...below are some pictures of where it sits right now with a tape measure for reference. I'll be pulling them off the car later today to get things proper. Now, I'm not able to find anything on the spring rates even after looking at the text on the springs themselves and the body of the shocks. Google didn't turn up anything helpful except for this PDF that gives you a "baseline" setting for where to start with the adjustments which is EXACTLY what I need.
http://www.andysautosport.com/additi...info/6m32u.pdf

 

I just checked the measurements. I raised the ride height exactly 0.5" on the front and lessened the pre-load by a marginal amount. One thing that surprised me is it was only about 2 turns loosening the pre-load till I could see space between the bottom of the spring and the fitting. Thus, I think there's basically no pre-load set on them. Still can't find any markings denoting the spring rate.

 

Yup, that's my understanding as well.

OP, looks like you have the older Flex, as mentioned earlier they don't ride as nice as the new Street Flex. IIRC the older Flex come with 10k/8k springs, I don't think they need a lot of pre-load so that is likely not your issue. You can do some calculation to see how much pre-load you need to get a nice bump/droop ratio, then compare it with TEIN recommendation, ideally you want 70-60/30-40.

 

That spring is 10 kg/cm2.

https://www.tein.co.jp/e/products/stsp.html

 

Thanks for the link. I didn't know that chart existed. I'm feeling a little dense though...even after consulting the chart I can't figure out how you were able to figure that out. None of the numbers on the tube and or the spring seem to exist in the chart.

 

I had Tein coilovers for a short period of time and remembered I had looked up the spring specs.

Search for Q100 in the chart. It's listed as SQ100.

I bet the rear springs say 800 on them, since someone mentioned that kit came with 10s and 8s.

 

Sounds like your preload was OK to begin with. As others have noted, preload doesn't affect spring rate. Usually all it does is needlessly reduce rebound travel, which would negatively affect ride quality, but that's not the case here.

When the ride is harsh over bumps, it is almost always due to excessive high-speed damping, not spring rate. Stiffer springs are definitely firmer, and will feel more "busy" over bumps due to higher natural frequency, but with good damping they won't be *harsh* over bumps/road impacts.

The old Tein SS coilovers I had with 9/7 springs were WAY harsher over bumps than the Ohlins I have now with 13/11 springs. With the Ohlins dampers the FD now rides more smooovely over bumps/potholes/etc. than my stock S2000.

With poor/excessive high-speed damping, going softer on spring rate won't do anything to reduce harshness, as the dampers just kind of lock up when bumps are encountered taking the springs out of the equation.