I call shenanigans. You may think you have ridden the GS500 to its limits, but I suggest you take a performance class like fotobits suggested. Topping out the speedo is not riding a bike to its limits. Riding a bike to its limits out of a track environment is unsafe for you and others on the road, ie. Don’t do it.
“I am the best there is at what I do, and what I do ain’t nice.”-Wolverine