hey guys I just bought a 2015 xf 8000 high country, I had it down on the lake and it toped out at 77mph, it got there pretty quick but I would like to squeeze a little more out of it without loosing to much bottom end. I've read that by the changing the spring in the driven clutch to one a little softer can help, I guess it is too stiff to let the belt go all the way down. I havnt played to much with the gearing or clutch spring and weights before, so just wondering what gearing would be the best.
need for speed
