Martin (notorious onm here) had his Williams get a 13.9 with an almost standard engine. OK it was a Mk1 which was stripped but that was free.GordonD said:Magazine reports say 15.3 seconds for the quarter mile. And they practice to see how to get the best times before they get that.
Anyone who thinks a cup, which has the same engine and just a bit lower weight, would do 14.1 is talking nonsense. The lower weight might be worth 1-2 tenths of a second.
Any Clio Sport that does 14s isn't standard. Any Clio Sport that does 14.1 is quite significantly modified. Modify them as much as is possible - ie, unlimited budget - and could get into the high 13s.