CAUTION: throttle-stop testing

[aerohead]

Originally Posted by Phase

Then what’s the best way to test?

It's a great question. You might start a dedicated thread for it.
Here at this thread, I'd like to limit any back and forth exclusively to the 'technique.'

[aerohead]

Originally Posted by Phase

I follow your website. Yeah testing is hard. Usually the best way that I’ve been “ testing drag” is “ feel of my car”. I drive so much that I can tell if something is off. Like you know how you can feel that difference in driving power on a wet road versus smooth dry concrete? I can kind of feel the diff with aero drag. I can feel how my car drives with and without my side mirrors on since I put them back on any time I go somewhere for an oil change or tire rotation and balance and so on. I know it’s not scientific, but it’s like muscle memory.

For example, people here are telling me to start my “ boat tail” at the end of my spoiler, and not to follow the roof line of my hatch because it doesn’t “ match the template “

But I’m assuming I can just extend the roofline and then add a spoiler for pressure recovery and maintain attached flow and tuft test it. Obviously I’d be able to “ feel” a diff with a boat tail keeping attached flow even if it’s not the template. I mean a Tesla model 3 has a pretty steep rear roof but a little spoiler and keeps attached flow

*Presently, aerodynamic engineers are earning an average, $ 109,499 ( US ) a year.
* At 50-weeks a year.
* 40-hours a week.
* 2,000-hours a year.
* It works out at $ 54.75/hour ( a bargain! )
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You might consider going on Thomasnet, and procure a professional consultant who'll collaborate on your project.
It doesn't seem that anything short of this will ever satisfy you.

[aerohead]

here are some quanta for VMAN455's pickup:
* inline 4-cyl. 2.4-liters
* 116-bhp @ 4,800 rpm
* 140 lb-ft torque @ 2,800 rpm
* Manual 5-speed plus transfer case, aux driveshaft and aux differential
* Driveline mechanical efficiency approx. 88.35%
* final drive ratio, 4.1673:1 ratio
* 20.1942-mph / 1,000 rpm ( if 2,800 rpm = 91-km/h )
* Tires, 225/75 R-15
* 712.97 revolutions / mile
* Top speed approx. 77.54-mph ( gear-limited at 80% power setting )
* Approx. delta- 123-rpm excursion during testing ( 4.39% of peak-torque rpm range )
* Approx. 25.719 square-feet projected frontal area ( 83% of gross )
* Coefficient of aerodynamic drag ( above 2WD's published Cd 0.44 )
* Curb weight, 3345-lb
* EPA test weight, 3635-lb
* GVWR, 5350-lb
* EPA 20 mpg HWY rating ( during National 55-MPH National Speed Limit )
* 22.2-mpg reported
* 17.2-gallons fuel capacity
* 381.8-miles HWY range to fuel starvation as reported