Sorry to dredge up an old thread, but I've been researching front springs lately. From what I've found, aside from being progressive rate, all the various Tempo front springs are the same spring rate as a stock EA82, around 146. Also, the earlier Tempos had even less of a spring rate, like around 115.
For those that suspect that perhaps Jeszek has rear Tempo springs, those too only have a 115 spring rate. But it is curious that his fit without any modification, but he still saw improved stiffness, lift, which indicates that these definitely were not off of ANY Tempo. Makes you wonder what the hell they came off of.
However, if you have to cut the Tempo springs to fit, then that will increase their spring rate. To what, I do not know, one would have to take them in to get tested. But either way, it sounds like a lot of trouble to go to for little gain.
So the search continues for a better candidate that hopefully doesn't need any cutting or modification. We should be concentrating on sports cars with large aftermarket followings, so that we can get them cheaply off of eBay, and have lots of variety with rates and lengths.
So has any investigating using newer Subaru springs?