Great input!

Regarding to the Hasport, are you referring to this one?

 

ASM

 

Development is expensive, verification is not. Rear wings, as we commonly see them in automotive applications, have the benefit of a built-in force balance in the wing supports. If these supports can be instrumented, all the relevant data can be collected. No need for an expensive, car sized wind tunnel. No need for complicated, full car CFD.

Throw the wing on, hook up the instruments, and go for a drive. Cheap. Yet no one does it.

Theory gets you your design, testing verifies your theory (and provides information for the consumer for marketing purposes). Without verification, we have no idea whether the part does what we think. As you said, low Reynolds number aerodynamics is far from intuitive.

 

Getting a basic force measurement doesn't tell a very complete story and that wasn't what I was talking about in reference to "technical details." I'm talking about flow interactions, boundary layer transitions, and unsteady effects. These can't be measured by putting a load cell on a wing support... so even if you get some net downforce numbers, you're far from having "all of the relevant data." All it will tell you is "yep, it yields a force." So does sitting on the trunk, but obviously there's more to planting the rear tires than putting Dr. Phil back there and telling him to hold on tight.

I'd venture to say most companies have some form of test data that shows a net force at the wing supports, but there's no need to release the data as it is probably proprietary information anyway.

And as for the comment that development is expensive and verification is not, I'm staring at a USN contract where the verification cost exceeds that for development. Maybe aerodynamicists cost less when they're working on cars?

 

from what I have heard from people who sell J's and voltex is that Voltex manufacturs the J's wings and that you are getting a voltex wing just with J's stickers... I dont know if this is 100% truth but they do look ALOT alike...

 

You are correct

 

That's what I'm saying, getting a basic force measurement is the complete story for a deck mounted rear wing on a "street" car. We are not running F1 cars, the flow interactions to the aft of the wing are going to be negligible. The numbers from the wing are the final numbers, all the important flow interactions happen upstream.

While I appreciate Dr. Phil humor, the logical fallacy doesn't provide for the fact that Dr. Phil will not be proving us with lift versus speed, drag versus speed, and L/D numbers all for every angle of attack the wing could be run at in the real world air flow mounted on the car. A basic load cell hooked to a data logger would do all this. "Yep, it yields a force" is a much different statement than, "Yep, it yields X lbs lift and Y lbs drag at Z AoA." These numbers would not only be useful in comparing the efficiency of competing brands, but also in selecting the wing best suited to your personal application and the settings to use for that wing at your current event. Additionally, those numbers are not at all proprietary data. The secret to protect is how to generate those numbers, obviously none of which would be revealed.

Verification is less expensive than development in this context. Aerodynamicists are needed for development of the element, they aren't needed to run a strain gauge.

 

I just typed a whole long paragraph, then I realized I just don't give a shit. Too much time wasted trying to share some thoughts on the topic, I've learned my lesson to never do it again.

Enjoy your strain gauge.

 

Forgive me for interjecting, but the above conversation seems to have just ended, and this seems like a good time/place to ask.

What's the purpose of the "3D" wings vs. a flat shape? Is it anything other than aesthetics?

 

hey dude. i still think sharing is important. u're right to say that putting load cells wont tell all but at least some form of information would make a difference for a consumer choice.

we can tell the net downforce thru a test like that but drag numbers might be harder to tell. MPH down a straight from a rolling start might give some numbers but only as an indication of relative amount of drag as compared to another wing.
ultimately, consumers need to make an informed choice.

And its sorely needed where I live but by far the rarest option we have here.