well as it says, what is the absolute fastest the flash has ever run before?

I have heard 13 trillion times light speed for Wally, but he has a better feat during the Human Race story line that I haven't seen measured.

Wally west went faster than time during the human race going faster thank a plankett the shortest unit of time new 52 Barry moved in a fraction of a fempto second which is so short light can only move between cells in a full fempto second so, currently Barry is much much much faster than light can react that fast purely on instinct

His top speed was faster than "instantly", Flash is faster than time itself at his best. crazy.

Please pardon the language.

I don't think its ever been said that he has hit a limit.