I have spent a while researching options and specs of the various suspension options for the ST185. Through this I have gathered a fair bit of info on spring rates and damping rates adopted by many. I will update the first post in due course but options are very limited now unless you go custom.
Unfortunately most are now discontinued (although I seem to have been able to order most of them and just received a long wait).
Discontinued List :-
Eibach lowering Springs
Tein HA coilovers
Tein Superstreet Coilovers
Koni 8641-1211 SPORT rebound adjustable strut insert (damper)
TRD Springs - various
KYB AGX adjustable struts
....... you can see the pattern.
Items still in manufacture
1) Toyota standard struts
2) Bilstein front strut insert (Inverted mono tube) Part No. P30-0352
(Note P = Insert & 30 indicates valve diameter) These are not 36mm or 46mm Heavy duty types as some sites suggest and most of the benefit of the mono tube is lost (lower unsprung mass and able to use a larger diameter valve to provide better sensitivity at high velocity - more plush ride quality whilst still firm) they basically have an inverted damper within a bottom strut casing that all fits inside the standard Toyota strut casing!
3) BC Racing coilover.
Having spoken to them and looked at the shock dynos I have reservations. They are reported as being quite compliant and suited for road use. The shock dyno suggests they run little bump but plenty of rebound damping. There has been some reluctance to offer lower spring rates (only 1-2KG lower than they offer) and an indication that if they did that the warranty would be void.
4) Bespoke suspension = ££££
Performance options are therefore quite limited and easy/quick UK rebuilds/spares may not continue for much longer for any of them??
Bilstein will offer a UK rebuild/repair/revalve on their offerings and BC do offer replacement inserts shipped from Taiwan but having been bitten by Tein and their rebuild options I am more inclined to work with a UK supplier that will hopefully be around for a long time. This has led me to research the options a bit more and consider some possibly stupid ideas.......
A) Bilstein Universal Motorsport Strut 46mm of valve! $500 each : -
http://www.bilsteinus.com/products/moto ... rts-strut/ Unfortunately not available in the UK and USA only
B) Look at building up a Group 4 escort type strut casing from this
http://www.motorsport-tools.com/coilove ... mm-id.html Laser cut some strut ears for the GT4 and weld them on. Use one of the various options of 36mm inverted Bilstein inserts from Grp4 escort, Pug 205 etc etc that can be easily & cheaply rebuilt & revalved (£70-£120 a corner it seems) and reliably sourced in UK from Bilstein or AVO. See:-
http://www.motorsport-tools.com/escort- ... capri.html Note:- the 300/70 damping is pretty close to the GT4 Specific insert they offer (ideally it could do with a bit more bump and I have yet to ascertain if they are linear or digressive valved on the escort rally insert). The Pug 205 rally insert seems a better fit (maybe as the unsprung mass is closer with it having a proper front hub and driveshaft etc.)
I believe the escorts seemed to use 200-450 lb springs so circa 4KG to 8 or 9KG/mm so not far off sensible GT4 rates for road use.
Has anyone used the Group 4 type Bilstein inserts in their rally days? Any comment if they are durable/sensible for the basis of a custom setup?