I finally found a setting for Tein CST that I am happy with.
Keep in mind the numbers mentioned are not all precise, better treat them as rough numbers.
My reference is a-spec by the way.
I am happy with the rear end so mainly tried three settings for the front:
R - 13.5"
13.5": Too much weight in the front, this adds front-end bites but when exceeds grip limit switches to under-steer sooner. The front doesn't feel as crisp as a-spec even though the grip level is higher, but the major deal breaker for me is the lost of rear-end feedback.
At this ride height, I measured from the lowest point of the thread to the bottom of the lower perch (let me call this perch height) and it's 35mm.
14": This is more like OE F-R difference. I immediately like the better front-rear balance and the crisper/stiffer front (because the spring preload increased). Unfortunately I soon find out that the preload is too much to the point that I can tell the damping is not enough to control the spring. Need to up the front damping to 9 to catch the spring but then the combination is just too stiff. At this point, I know I only need to lower the spring a bit to lessen the preload.
Perch height is 42mm.
--Updated from 13.9" to 13.8"--
13.8": Point two inch doesn't sound much but it made a big difference! I like a-spec front end so use it as reference. With damping set to 10 the front is close to a-spec crisp but a few notches smoother. I suppose by upping the damping it will be really close to a-spec. The 0.1" difference also somehow makes the F-R balance better than 14", but I need to corner the car harder to really say for sure
Perch height is 4mm.
0 is hardest; 16 is softest
F-R: 10 - 13
The recommended 8-10 setting was too hard for where I live when paired with 13.5" - 13.5" ride heights.
I get CST to have softer rear for comfort, so run it at the softest setting I can live with. I have tried 10~13 and think 11~13 are all pretty decent setting to have both comfort and handling.
The front I should experiment a bit with the new-found front ride height, but 9-11 are decent compromises.
One thing worth mentioning is that I feel the damping change per click is more significant at the front than the rear. Or maybe it's because I sit in the front..
I will write a complete review and post some pics after I install the RSB.