1000m is close enough to 5/8 mile, so i'd guess you were around 145-148mph

Compared to similar powered cars that have run the 1000m here in Australia, that's pretty good.

 

Interesting. You're pretty much dead-on.

I went back and put the atmospheric data into the drag computer I have and the DA for the day was 3980 ft It was dead-on with the morning's run and it showed the wind was killing the power way more than I figured.

I queried it for 1000m since it was accurate at the 1/2 and 1 mile. The 1000m was 147.52mph.

For this morning it predicted:
1/2mi 139.15 -- I ran 139.4
1 mi 161.58 -- I ran 160.9

I suspect the IAT is heating up in the second 1/2 mi which is causing the HP to drop a hair -- which the calculator does not predict.

 

See my post where I talked about the drag calculator to look at the atmospheric effects from the event. And yes, it showed that with a shift from a 17-22 mph headwind to a 4 mph tailwind the predicted speed jumped from 162 to 169 -- all else being the same.

 

not saying it limits top speed but it will impede with every gear shift. the little slip you get is way less than the electronics interfering and dropping your rpm below 2,000. It is time and distance you cannot make up.

 

The last standing mile event I did was in 2010 in Florida. Same thing almost 4 hours between runs. By 10AM it was 105F on the tarmac. I managed only two runs because when another group came in late around noon they let them jump the line, while people were waiting for 2-3 hours. I left, two runs a total of 7 hours sitting in my car on an airport runway ... stupid.

My best run was 175mph with DSC off but I basically only had two launches to test. The car was AWD and manual so the launch is not easy. First run was 157mph with DSC on, was just not able to put power down.
Now in the old 997 turbo you only had two settings for DSC, either on or off, not three as with the Jags so track DSC might be ok, it is just the drop in rpm that is hard to make up.