Blown Fuel Artist

Noun: Someone that thinks they are the "be-all/end-all" of a particular topic or discussion. Particularly within the motorsports/racing fields.
Noun: A "know-it-all", "one-upper", someone that always has a better story than yours. Also, pompous, and/or smug.

"That Larry..he sure knows a lot about transmissions....he's quite the blown fuel artist....."

"Boy that Stevie, he sure tells lots of made-up stories about Don Garlits, he must be a blown fuel artist"