Well...guys,
Maybe I wasn't too clear in the other posting...so here are some details...
There is a quite simple (pure physics, dynamics..) reason that the polyurethane bushings (at least the one on the market right now...the single axis rotation bushing...) CANNOT be use for the rear suspensions arms 1 and 2 as correctly "Gary ST165" mentioned. You can, however use them pretty much anywhere else. Or, rephrasing....one can still use the polys even for the rear arms 1 and 2 providing that they are willing to spend enormous amount of time in tweaking the rear suspension.
Here is the reason:
Remember that in all the 4wd celicas (165, 185, 205) the rear subframe is FLOATING with respect of the chassis, hence with respect of the front suspension arms...in fact, the rear subframe mounting mechanism to the chassis allows quite a big of variations (at least few mm; I would say more than 5mm...) in the plane parallel with the attachment points. So, in other words, the rear suspension geometry can be easily altered just by moving the rear subframe a bit around the mounting points. This thing is definitely not good, in fact quite bad... Remember, the 4wd celica was NOT designed as a real 4wd car from the get go, instead, the 4wd celicas appeared as the response to Toyota's need for a 4wd car for their WRC rally campaign...So the Toyota engineers had slapped a rear dif carrier with all the necessary stuff to a fwd existing celica chassis. By doing that the Toyota engineers were faced with quite few problems...and they found solution to all of those...good and clever solutions...They quickly figured out that by adding a floating rear subframe with the rear suspension arms attached to it, there will be quite few variations from car to car and even on the same car once the subframe was unbolted from the chassis and put back on the chassis (after changing the differential or subframe bushings for example...); these variations would cause a possible heavy laterally preload on the rear suspensions arms 1 and 2 IF single axis rotation type of bushings were to be used for these both rear suspension arms. So, the Toyota engineers ingeniously used SPHERICAL bushings. Those bushings does allow for small variation in the rear suspension geometry WITHOUT laterally loading them. ...Simple as that !!!.
This explains why some of you (lucky...) guys have no problems with poly rear bushings, while others not so lucky (..I among those...???!!!) have had such a bad experience with them...Is just the difference between the rear arms being laterally loaded vs nonloaded...(or minimal load...)
The bottom line: the one axis rotation bushings (...poly bushings as they are designed today...) are NOT TO BE USED for the rear suspension arm 1 and 2. They simply are not designed for this application. However, they can still be used provided that extensive tweaking the subframe position to the chassis will be done to ensure NO lateral load is applied to the rear suspensions arms. (it is critically important that absolutely ZERO laterally load be applied on the rear suspension arms, otherwise the rear suspension will react quite unpredictable and highly accelerated bushings wear will be present...)
So when I said "for track use..." I meant to say that on a car prepared specifically for track use there are extensive suspension mods anyway, so for these cars spending extensive amount of time for tweaking the suspension is pretty much expected ...
regards,