I can't speak for how it does with the eclipse as I'm still using an oem but I do have a OS Geiken twin disk in my skyline and I absolutely love it. It sucks in stop and go but launching and on a long cruise or roll racing it's amazing. I personally haven't done much research on them for our...
Welcome to the forum. Pics or a link for us to look at would be of great help. Also for future reference the GT-R comes with a RB26 not a 25. Keeps us posted m