Bolt-on Rear Wing

[Rosticles]

As I have stated before. I know that there is turbulence, I know that these numbers are optimal. I know it will never hit these numbers.

This thread was started in an attempt to understand if this was applicable to autocross. I am still engineering the design and was trying to make sure the form fit before I did "get ahead of myself"

[plucas]

No it isn't applicable in autocross then is the answer. You would have to have a huge multi-element rear wing and something crazy in the front to balance it out. I would look to FSAE cars to get an idea.

[CSG Mike]

Originally Posted by Rosticles

CSG Mike; The data is from table sets for the wing profile. It is a well documented profile and I did the calculations for a reynolds number of 100,000 and Ncrit=9, for sea level air. This gives a maximum Cl/Cd of 156.5 @ 6.25 degrees. This does not take into account the mounting solution and I understand it will have a constant drag coefficient that I have yet to calculate.

Sorry, free flowing data has zero use on a car. It's anecdotal at best. The air flowing over the wing isn't smooth.

Seems you're just pulling existing numbers, not doing the modeling yourself.

[chrisl]

Originally Posted by plucas

This sounds like you are getting a head of yourself. Are you pulling these Cl and Cd numbers from a table? Also you state that these numbers are optimal with perfect laminar airflow. You know that most cars start to transition to turbulent flow at around 60mph. The airflow will not be laminar on this wing at 100mph. I bet that wing stalls at 13 degrees.

A wing will work very different on the back of a car than in free stream air. I have done extensive work with this using cfd. If you want some help with this, let me know. My background is an engineer specializing in fluid flow and heat transfer.

Laminar vs turbulent shouldn't make much of a difference to the lift values (though it will change the drag), and turbulent airflow is actually more resistant to stalling than laminar is. I do agree though that freestream numbers don't mean a lot for a wing mounted on a car. I also agree that even if this wing can make 300lb of downforce at 100mph, it's pretty useless at autocross - that means that it's only making 75lb at 50mph, and 27lb at 30mph, both of which are much closer to the cornering speeds seen at a lot of autocross courses.

[xwd]

Originally Posted by Vracer111

Simply put, wings are not allowed for SOLO II competition with production cars (even in Modified class), spoilers are what's allowed...

The rules change based on what specific class you are in, even for modified.

Wings are allowed in the Street Modified classes and X Prepared. But as noted the mounting for this would be illegal, the wings have to mount to the trunklid.

[bkblitzed]

the other day i saw an s2k with the exact same design wing. It looked like a dirt track race car