Split Backstay Adjuster
A backstay adjuster is something I wouldn't leave home without - one of the biggest bangs-for-the-buck there is for sailing performance.Since you mentioned the rope/block/pully/wire system it sounds like this is on a split backstay. If the system isn't able to easily crank up the backstay tension there is another low-cost setup available - it's a pincer system that pulls the split part of the backstay together. This is what I use on my boat. It uses a Johnson "split backstay adjuster" and has five sheaves so the bending of the wire is minimized. They make two sizes and I have the larger one, cost around $60 a few years ago plus 3/8-inch line and blocks. With a relatively light-weight block setup one can really crank up the backstay tension. This setup does really well for me in the wind ranges you're talking about. There is only one downside to my setup and that is the adjuster part does not automatically go back up when the tension is removed from the line - sometimes, but not very often. I need to install another line to raise it (remove tension) but in almost ten years I haven't got around to it. Kinda low on the to-do list.The other systems, such as hydraulic or mechanical, are too expensive and I'd never get my investment out.