These challenges are partly about setting the fastest overall time but more so,about the enjoyment that comes from beating your nemesis. So in my mind even if your not as quick as the leaders post your time anyway,and try and beat the guy in front of you and quite often mini rivalry's develop, good luck and thanks to every one whos entered a time
I had a good old rivalry with... myself.
Time: 00:52.393
Bhp: 318hp
P.P: 589
Wheel\DS3: DS3 AT
There was at least .4-.5 for me to be had before I change setup (I think the gearing's OK, more tweaking - I'd probably gain as much going to MT

), but I'm having more fun checking different cars, now, since I didn't even get time to run in the car before we got PSN back.
Some interesting cars in that area are the R390 road car (no permanent mods), RS200 rally (maxed), and the cars I think can definitely threaten the 111R RM in the right hands - the Asparadrink RX-7 and the Arta Garaiya 08. These last two I got down into the 52s with very little effort, setup, and only a few laps.
There's a few other road cars around that area that aren't bad, either. Audi R8 (no permanent mods, including aero) felt good, and I think I even got down around 54 with a bone stock Enzo + oil and R3s. Point, brake, point...
Anyway, enough blather. Great times, competent people - let me know if you can share setups ;-). Tip of the hat to Type_raveR, who pulled that time with the mid-range turbo, I assume.