hey, this is the low budget seat mod:
Technical Articles: Low-budget seat modification for S13
I got it off of 240sxtech.com
I was quite skeptical that it would do any good but after doing it (just last night), I'm amazed at how much more comfortable my seat is.
(After you read the article) - I removed both of the top two springs, leaving only the bottom one on, and I am liking it so far.
I also bent in the bolsters, as the author states is Step 3, using a long wrench as a pry bar and I am truly impressed at the increased support that this mod provides for free!
I could never find a comfortable position in my seat before, but after the first day of driving with it like this, I have no complaints. It even hugs noticeably better on turns
Of course, I'm sure it's nothing like what a real racing seat would be like, but, for the price, it can't be beat.