by Jamie N » Thu 10.09.2015, 19:27
John, I used the Honda rubber spring seats because i had them here, and because they were a similar size, however the fact is there are a multitude of different types you could use, you dont really need to go searching specifically for the Type R ones, as long as the size of the rubber is approx 34cm outside diameter, (11.5cm across the centre, all 4 are the same size) and around 5mm thick then they will work just fine, I have seen ones on some Mazda's that look ideal as well, including the ones on an MX5 and Mazda 6.
Another couple of options are also possible, you could slice the ones you have down to 5mm, probably the easiest method and free! and to be honest its extremely unlikely if you did cut them that you would think you need to go back to the thicker ones, if you do i will send you mine!, i wont be putting them back on, if i had not had the Honda ones sitting spare this is the method i would have used instead, clamp them gently in a vice and go round it with a good new hacksaw then maybe a smooth over the cut side with a sanding wheel on the angle grinder.
Or you could find some 5mm rubber sheet or matt and cut them out of that, it wont really make much difference, providing you use decent rubber and the spring is making contact with it all the way round and it cant move, then it will do the job required of it... i.e vibration damping between the spring and the top mount, albeit possibly less damping than the ( excessively?) thick originals, but i have driven mine enough miles now since doing it and i have noticed nothing different vibration wise. Aside from that there is the train of thought that says a thick rubber spring seat will help with vibration but may negate sharper, more precise handling, and i have looked at a mutitude of different modern day suspension setups and have seen none that uses a very thick rubber spring seat like the Elan, none at all, they almost always are around 5mm thick. If you look at Coilovers, often they run without any rubber between the spring and the top mount.
Its a dead easy job as well, providing your suspension nuts and bolts are not seized solid, i didn't even need to use spring compressors to remove or refit them, they can be pushed down enough by hand to locate the top mount and thread the nut back on.
Its not a massive modification in the grand scheme of things but if you feel a 25mm drop would be beneficial then its worth doing, who knows it may even sharpen up the handling!.