I was just going to post a detailed discussion of throttle stop testing (especially versus other amateur testing techniques for drag) but I just watched this video for the first time since I made it 9 months ago.
It the longest I have done but it covers quite clearly:
- how throttle stop testing is done
- what its advantages and disadvantages are
- and gives examples of its use with aerodynamic changes that are going to give clear changes in drag (eg ride height, windows up /down, wing in air brake position).
Very obviously Aerohead either never watched the video, didn't understand it, or watched it and forgot its contents. (And that's OK, but you'd think he'd ask for details of the testing if he didn't get it.)
The other video that is germane is this one, which includes reverting to standard aero configuration no less than
three times during the test session to ensure the results in this form were consistent.
This video also shows the step-by-step of the development of the Edgarwit external air curtains' position and their tuning. (And I must have been enthusiastic. I did a lot of testing in the one session!)
Note that the 8 per cent reduction in drag with the Edgarwits was only in dead-calm conditions. It was about 4-5 per cent in windier conditions (and again, note that the throttle stop testing shows this degree of variation).