I haven't had mine higher than about 115 -- but it's quite anti-climatic. I've got full suspension mods - Bilsteins, IPD springs, poly-everywhere it's available, upper/lower front braces, big bars, adjustable torque arms and Panhard and V-rated 225-50-16 tires. Very stable and comfortable at speed.

I had my speedo recalibrated by the shop that advertises in Rolling magazine. It's very accurate for speed and odometer (they are calibrated separately). You probably won't hurt the speedo unless you wrap it around till the needle hits the 'stop' -- if you keep going past that, you've got a good shot at breaking something.

Get 'flyboy' to post - he road races his 347 powered 242 and has it at speed often.

Wind noise on the other hand is quite a problem. Bricks and all....