You mean like a blower? And by mechanical, I'm assuming you mean a Roots-type supercharger?
If so, I've seen a couple of them on the salt flats:
[img]
http://www.chevyasylum.com/bsf2003/wf/031018/031018_060r8.jpg[/img]
This is a front-engine dragster with in inline 6 motor (I don't know exactly what motor it is) and a Whipple roots-type blower. It ran at the Bonneville Salt Flats last October. Their high speed was a little over 188.
