The Phil Knox fleet - 34 years of aeromodding

[JacobLeSann]

So, a sort of artificial roofline made up of air? I’m gonna have to get better with the terms you’ve used to fully understand what you’re saying. I’m impressed with how you’ve kept the rear window free of obstructions.

What happened to this car? I’ve always loved the CRX, a dream car for me.

[aerohead]

Yes, dead air pools within the perimeter, and the laminar flow above it just skims off it, as if it were a solid boundary. It must be airtight in order to work. No porosity.
The same happens under a car with the rear fascia, if it's properly configured.
Rocker panel extensions along with the rear valance can capture an 'upside-down' pool of air below the belly, leaving laminar airflow to skip over underneath it, as if a belly pan were above it. Subaru proved this with their 1985 Cd 0.29 XT.
I still have the CRX.

[JacobLeSann]

That’s awesome that you still have it. Any info on your average MPG with it? I like this design.

[aerohead]

She went from 52-to-65 mpg, at the old, double-nickel national speed limit.
From the speed record at Bonneville, top speed and coastdown testing at the Chrysler Proving Grounds, according to Glen Scharf at GM Aero Lab., she was around Cd 0.235, down from Cd 0.32 ( HF model with single side mirror and 165mm tires )
We have 345,000-miles of mpg data for the car.

[JacobLeSann]

Would you have any relevant texts describing how this design works in detail? It’s very interesting. I don’t think it would work on my car as it’s a notchback, but I really like the practicality and aesthetics of this design. 0.235 without a boat tail is VERY interesting.

[freebeard]

Similar situation to your mid-engined hypercars and pickup trucks.

Flying buttresses and a spoiler.

[aerohead]

Originally Posted by JacobLeSann

Would you have any relevant texts describing how this design works in detail? It’s very interesting. I don’t think it would work on my car as it’s a notchback, but I really like the practicality and aesthetics of this design. 0.235 without a boat tail is VERY interesting.

I essentially selected the lowest drag architecture component from each of R.G.S. White's 1968 recipe categories for low drag, published in my CRC Handbook from the 1970s.
The summation of the categories is entered into an equation that he provides, and using all the 'best' components yields Cd 0.245.
Throw in Korff's NASCAR cooling inlet, rear skirts,and all the belly pan you can get away with, Cd 0.235 is not much of a reach.
At the time I was modifying, Sergio Pininfarina published that, all extant car shapes, already accepted by the public, could easily be modified to achieve Cd 0.25.
Hucho does address a signal-to-noise ratio, with respect to White's presentation, that's appropriate for the conversation.
Essentially, all the low drag cars of today look remarkably like White's 1968 creation.
PS, I did add 12-inches to the CRX.
https://ecomodder.com/forum/member-a...-drag-cars.jpg