In thirteen passes there were two missed-third-gears*, one killed-it-on-the-last-yellow*, one rolled-through-the-lights-for-no-time*, six total loss-due-to-reds, one baited-the-opponent-into-redding-too, plus a couple of incidents my mind is blocking because they were even more embarrassing*, and zero "hooked" runs. Nevertheless, I managed to increase my highest trap speed by 0.15 MPH and lower my 60-foot best by 0.038 seconds. That still leaves the white (manual) coupe 0.134 seconds and 2.14 MPH slower than the black (auto) convertible, as well as 0.143 seconds slower 60-foot.
* I almost never have this kind of problem with the automatic convertible.
One positive way to look at it: all that improvement was on the "stock" FRPP Pro-Cal tune; BamaChips' Torque tune is usually worth about 1.5 MPH, the Performance tune worth a couple tenths ET, and the Race tune usually lifts both a little less than the individuals. Somehow I scrambled the SCT software when I got updates, so it's pretty much useless right now.
The heavy GT500 wheels and tires undoubtedly slow the whole show down, and they certainly don't have much grip off the line. Next time I'll try to have the lighter "Fanblades" with Bridgestone R-compound tires on. Either those or the new track treatment at Qualcomm were responsible for tiny improvements in the black car's numbers last month. We shall see. One change at a time, as Mr Science says.
As for actual numbers ... Did I mention embarrassing?
Cheers!