According to The Guinness Book of World Records, Jose Ramon
Areitio threw the fastest Jai Alai ball ever. It was clocked at
188 mph on Friday, August 3, 1979 at Newport Jai Alai in Rhode
Although Badminton and Golf have exceeded this threshold. I played the clip on JTV when Golf extreme driver, Jason Zuback on an episode of Sport Science, blasted a tee shot 204mph (albeit I think it was a golf-illegal club and golf-illegal T shot from what I read on follow up on forums).
The official badminton smash record is 332 km/h (206 mph), set by Chinese badminton doubles player Fu Haifeng in the 2005 Sudirman Cup.
In addition, to the OP comment, Lopez and a Golfer both fired off 3 shots, in a fronton in Spain, back in June, (the video is online somewhere Merry Festival I think) where Lopez was able to throw a reverse 150mph (240kph) while the golfer bested him by 1kph.
I assume since Lopez decided to throw reverse that he has a weaker right side, so I wonder how a strong right side player would fare. I have to guess that someone who has a stronger right side, Solo/Goiko, would throw a much faster shot that a strong Lopez reverse, no?
I'd love to get a hold of a radar gun at Dania for some fun!