The M2 is currently unhappy with me, so I took the track car my brother and I have been building to Road America last week. It's a 1996 C4 Corvette with a bunch of fun aero, some home-built, some custom carbon. It's got a mild build LS3 and a tremec T-56 Magnum transmission. Add in some Penske coilovers, decent brakes, full heim joint suspension and you're left with a 500+ HP, 3000# "street" car. This was run on 275 wide Nankangs on 17"x11 wheels.
Not shown - boiling the brakes right before the kink on the next lap.
The last lap is the fastest in this video, with the last lap at a 2:27.14. I got stuck behind a radical for the first few corners and it caused the lap to be 3.5 seconds off pace to start vs. my other fastest lap of the day. If I combine all laps, the theoretical best was a 2:22.5. Not bad for a car with a home made plywood splitter and an old truck motor with 175,000 miles on it.