Well, here's the answer: It happened in 2000 at The California Speedway's 2 mile oval track.
Driver was Gil de Ferran in a Reynard-HONDA.....
Average speed was 241.428 MPH

He must have been hitting 260 in the straights....in a HONDA!!!!!!!!!
Too fast, after this CART started looking for ways to limit speed on the big open tracks......
Barrie