Following on from a couple of posts in another thread
Here's some useful stuff I've accumulated over the course of time
Final object "hardness" is measured by it's durometer. There are two common ranges bandied about, Shore A and Shore D
There's an (immensely tedious) informative description on the why's and wherefores of durometers
HERE. Be aware you'll need good eyelid matchsticks to make the end
Shore A is most appropriate to car polybushing. It seems to go from about shore 30, apparently the same as natural rubber, to shore 100 which is slightly harder than standard polybush material
There is some common ground between the two ranges. It would seem that 90 Shore A is equivalent to 30-35 shore D depending on which literature your reading at the time
When I made my rear diff mount I used 65 Shore D compound. This is oficially plastic and unlikely to be suitable for suspension applications where I imagine it might prove a little too brittle
Here's some useful information from
SuperFlex
Superflex wrote:
Guide to Hardness Selection
It has become necessary to dispel many myths & misconceptions on application of hardness caused by imitation.
SuperFlex grades are all pre determined in hardness suitable for road to fast road use. As a customer, you do not have to choose the hardness, unless an option on our listings.
On some cars all four production hardness are applied in various positions around the car, depending on the load in that location – as tested and pre determined by us.
Colours of SuperFlex bushes do not identify hardness, with the exception of 95 shore which is only produced in red.
To simply blanket a car with one hardness and call it: comfort, dynamic, performance, race, road or touring displays compromise or limited production capability and doesn’t work.
See selection chart below - based on nearly 30 years PU manufacturing experience:
Guide to Hardness Selection
70 Shore Typically subframe mountings where low NVH is a priority and situations where compliance is desirable
80 Shore Typically wishbone, radius rod, non coil over shock eye bushes
90 Shore Typically leaf spring eyes or more heavily loaded wishbones & radius arms, trunnion bushes where replacing rubber
95 Shore Typically intensely loaded coil over shock bushes, trunnion bushes where replacing nylon – red only
As well as pre-formed bushings Superflex do also provide "raw" bars of PU (laughably, IMO, called sprods
) in varying sizes and shores, as seen
HERE and a good range of ARB polybushes which may be of interest to those straying away from stock Mr T
I've tried to contact them in the past regarding the purchase of raw materials. They've never come back to me
They supply a limited range of Celica bushes
Powerflex(
http://www.powerflex.co.uk) offer a good array of Celica specific bushes (although these must be purchased through Fensport) as well as a range of universal, machine to suit, bushings which might prove useful. They are rather more tight lipped about material specs in the public domain. Whether they'd oblige in response to email I don't know
These are the folks who supplied my "replacement" diff subframe->main subframe bushings in the form of some 200 series washers. They also supply "top hat" type bushes which might prove seful in suspension setups although further durometer information would help make a more informed decision
There are, seemingly, few suitable compounds available to Joe public in the UK
Mould Life (
www.mouldlife.co.uk) do have a few products which might be of interest depending on how far you want to go
They offer PT Flex products (from Polyflex in the US) in grades from 50-70 shore A. Probably suitable for uprating engine mounts etc but not a great deal of use for custom suspension applications
They also offer Rencast 6414A which, as far as I can tell from the somewhat confuddling datasheet, can be mixed to produce various end results from 65 Shore D to 80 shore A which might make it ideal
Feel free to add any additional information, suppliers etc etc to this thread
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