After updating the suspension (Bilstein), tires (245mm Hoosier R7) and brakes (Powerbrake 4 piston BBK) the best our 2001 BMW could do in TTD trim was a 1:27.6 lap at a NASA event in March 2016 - missing the old TTD track record by a tenth. We came back after some suspension tweaks (MCS TT2) and fresh Hoosier tires and got down to a 1:25.0 at a test day in Nov 2016. 

With a custom full length header, exhaust and CAI (but no tune) we returned with NASA in March 2017 to smash the old TTD track record by nearly 4 seconds, with this 1:23.789 lap. No other TTD competition that day but it was still fun racing against the record books!