Flash used at night time racing events

[nonac]

I recently attended the "Knoxville Nationals" which is the Superbowl of dirt Sprint Car auto racing.  I noted several photographers on the infield that were taking pictures of the cars as they came into and slid through the corners.  They appeared to be using DSLR's with a big bracket mounted flash of some type.  The flash had a large reflector on it, probably at least 12" in diameter.  Does anyone know what type of flash units that these guys are using?  There were probably at least a dozen photographers with them at different points around the track.  Thanks.

[Drizzt321]

At a guess, Quantum or Metz or Canon/Nikon branded speedlites, possibly 2-3 of them on a single bracket with, as you said, the large reflector to concentrate all the light from them as much as possible.