I don't know what would make you think that good strngs would make the bow shoot faster than advertised IBO. Very few bows even approach IBO speeds because other things are added to the string that slow things down.

You may gather some extra speed over what the bow is now shooting. Last year I put Winner's Choice on my ShadowCat and gained an amzing 11 fps.The bow came stock with Brownell Ultracam. Realistically I was looking for 5 fps. However, I didn't change the strings for the speed gain so much as stability of the bow. No creep and no peep rotation. And with no creep the bow does not change it's tune over time.

A friend of mine put them on his Diamond Victory and gained no speed at all. Sometimes it's a matter of what the strings are made of along with the process of manufacture. If you look at the websites of Brownell and BCY you see that they list the pertinent properties of each string material. For BCY 8125 is noted for speed. This is because it is a lighter material.

No matter, you can expect the average bowhunting setup to produce speeds 30-50 fps slower than IBO just due to the fact that you may shoot heavier arrows, and anything added to the string adds weight, which slows things down. That being said, a good set of strings is always a good investment.