Bump for a mini-write up on my BC Racing BR Series non-inverted coilover experience after a year:
I've noticed that spring preload and adjuster settings can make a world of difference on these coilovers. Here's my experience with the different settings on re070s and toyo proxes 4 tires all at the recommended 14" front /13.5" rear ride height setting:
RE070:
full soft = ride the wave. a little bit too comfy..spring isn't being controlled enough.
5 clicks from full soft = the right setting for the stiff sidewall for ride comfort around town.
10 clicks = less roll but more pain over potholes and ridges
15 clicks on up = autocross settings, not street friendly over bumps.
Toyo Proxes 4 (gummy bear tires):
full soft = dear god, rides like an 1980's oldsmobile
5 clicks from soft = spring is not controlled by the damper, rebound too high with no compression.
8 clicks from full soft = spring still not controlled as much, very wavy and bouncy but the bounce is slowed over say full soft. the damper is working, but needs more behind it to control the spring rate and tire sidewall.
10 clicks from soft = almost right, compression is up to hold the spring, but rebound a bit too much.
12 clicks from soft = perfect for these tires. a little too much rebound, but appropriate compression. bumps are mostly soaked up by the damper, although you will feel some hits which get settled right away. multiple succession of bumps causes the tires to lose traction in a turn, meaning the damper is being overwhelmed, but hey...still comfortable.
higher than 12 = haven't tried yet on these tires since they're really just that awful for performance driving. i have a feeling that you'd have less roll, less damper compliance, and more tire sliding.
Whats nice to note, see and experience is that the adjuster does work and does a decent job of making appropriate changes considering the price range these are in. I think the different tires have shown that its a very significant advantage to having an adjustable shock on your car. I know the 65% critically damped motion ratio is the ideal, but without factoring in the tire sidewall, you can really under or overshoot your desired ride quality and performance with a non-adjustable shock, IMO. Even though these aren't that good in the grand scheme of shocks, they're still able to support different tire compounds enough that I can find a sweet spot for the track and street at different settings. Total recommended advantage to have on your car, 65% or not.
I've had the opportunity to flog an Acura TL Type-S around and noted that even that oem sport suspension has a lot of the same failings as the BC setup. It'll bobble and lose composure over ripples in the road and has a bit too much rebound over the bigger holes in the road. A lower spring rate helps mitigate some of the crashing, but the valving felt very familar to me.
Just to add this thought: For $1k, these are a tremendous value and I'm still surprised at their capability almost a year later. No leaks or issues with the shocks yet and no signs of coilbind either. They're able to compete at the higher levels of autocross against more expensive brands and don't kill your backside over 98% of the roads around here when they're on the right settings. I'm very pleased.
Issues to date:
Front camber plates squeak.
Rears clunk occasionally, but I'm starting to think thats more from the X-Brace needing to be tightened down at the strut tops.
Overheated the front struts during back to back runs through the Tail of the Dragon on RE070s. Adjusters slipped into their clicks and the shock response became slower and wonky. I don't have a technical way to describe it other than wonky.
Things I'd improve on:
More strut travel. Total travel is 122mm...not the least on the market, but not the 164mm that TiC can boast or the 162mm that RCE has on their T2's.
Better springs. Something thats lighter, more linear, less coils...like a Swift.
Better valving. Minor complaint because I'm used to the JDM way of valving, but I definitely prefer how the Europeans do it instead. Driving an M3 or any 3 series sport suspension vs. the competing Japanese sport suspension is a total eye-opener in valving philosophy.