S197 BOSS 302 Race Car Build Thread Build Thread

[AJ Hartman]

Yes. Since we make them we can just leave them blank. Use your current endplate as your template for the holes and your all set.

 

[ArizonaBOSS]

OK got the APR wing stub repaired. Should have taken some more photos but whatever.
I dremeled out the remaining epoxy from the riv-nut installation and created a pocket within the wing stub for an axial load to be distributed.
Then I took a couple long M6 bolts, and attached a thread-on flange and a nylock nut to 1) anchor the stud and create more surface area for the endplate to pull on and 2) resist rotation of the stud when attaching a nut to secure the end plate.
I embedded these in fresh epoxy and let it sit overnight to cure. Result: studs.







Endplate only sustained minor damage despite flying off the car on-track due to weak initial mounting repair...should be quite solid now.



Car is basically ready to run at the end of the month, now

 

[Grant 302]

Good work. That should hold nicely.

 

[ArizonaBOSS]

Good work. That should hold nicely.

Fingers crossed

And before anyone asks I did clean up that epoxy with some sandpaper so it doesn't look as janky as it does in those photos.

 

[VoodooBoss]

Looks better than the paper plate.

 

[ArizonaBOSS]

I'll take that as a compliment

 

[TymeSlayer]

Excellent write up of the race, the story was a great read and the results not to shabby either. Can't get enough of your drive to the championship!

 

[steveespo]

Looks solid. Winning makes it look even better. great job out there.

 

[ArizonaBOSS]

Was waiting for Head-On Photos to deliver my photo order from Thunderhill...in the meantime here are the proofs:

http://headonphotos.net/gallery/NASA/NASANATS17/Group C/41/index.html

 

[Fabman]

Was waiting for Head-On Photos to deliver my photo order from Thunderhill...in the meantime here are the proofs:

http://headonphotos.net/gallery/NASA/NASANATS17/Group C/41/index.html

Looking REALLY good!

 

[superhero]

Was waiting for Head-On Photos to deliver my photo order from Thunderhill...in the meantime here are the proofs:

http://headonphotos.net/gallery/NASA/NASANATS17/Group C/41/index.html

May I ask a question... What are the purpose of the end plates. I understand the function of the main wing. To apply downward pressure as air flows over it. But the side plates has me wondering. Are the side plates like stabilizer to keep the rear end from a side to side movement? But for that to happen wouldn't they need to have some sort of an angle to them. The only thing that I can compare them to is an airplanes wing end plates. But on the airplane the end plates are on some sort of an angle, which makes sense and I understand that. But on the car there mounted straight up and down.

Thank you

 

[steveespo]

End plates are mainly there to prevent turbulent flow separation on the end of the wing which reduces drag and maintains wing effectiveness. They also act as barriers to prevent disturbed air coming onto the wing and also disrupting smooth flow. Our simple wing designs don't really function as side force generators like more advanced cars (F1, WEC etc) but may help a little.


Sent from my iPhone using Tapatalk

 

[ArizonaBOSS]

@superhero , @steveespo said it pretty well. At the end of the day, for an "inverted" airfoil like on a race car, the downforce is generated primarily by flow UNDER the wing. The endplates help to control that flow so (compared to baseline) you can get equivalent downforce at lower drag, or higher downforce at the same drag.
I have also heard some pros describe them as "rudders" that help steer the car; just that our fluid is air, not water

@AJ Hartman wrote a good blog post about this stuff here, but I think he will be too busy whooping up on the AI field at NASA Eastern States Championships at Sebring this weekend to respond in the next few days

 

[Grant 302]

May I ask a question... What are the purpose of the end plates. I understand the function of the main wing. To apply downward pressure as air flows over it. But the side plates has me wondering. Are the side plates like stabilizer to keep the rear end from a side to side movement? But for that to happen wouldn't they need to have some sort of an angle to them. The only thing that I can compare them to is an airplanes wing end plates. But on the airplane the end plates are on some sort of an angle, which makes sense and I understand that. But on the car there mounted straight up and down.

Thank you

In lay terms, the main function is to keep the high pressure from the upper side from spilling into the low pressure underside. It's preventing the mixing of flow that normally create large wingtip vortices.

When compared to a wing without endplates, it effectively acts like a longer wing. And in racing, that's usually what's regulated.

@AJ Hartman wrote a good blog post about this stuff here

Cool stuff. Especially that little notch.

 

[Fabman]

Cool stuff. Especially that little notch.

Yeah, I see that same notch on other things he makes...I wonder how it works?

 

[antman450]

Airflow around any moving object is a matter of high and low pressure zones which results in turbulence. Is the same reason we have wind on our planet, high versus low pressure zones and air trying to fill the gaps from high to low pressure. The whole point of aero is to manipulate the high and low pressure zones, hence turbulence and drag, to the best of your advantage. Oversimplified, but that’s from my fluid dynamics and physics classes in college. I used to love all the simulations we did with colored dye in clear liquids.


Sent from my iPhone using Tapatalk

 

[RES_22]

Google "Simon McBeath" in Race Car Engineering mag.

Brilliant aero guy who can explain with examples.

 

[LERCH]

Has anyone tried using vortex generators on the underside of the wing?

Sent from my SM-G950U using Tapatalk

 

[antman450]

What my main concern is actually how to add more front downforce. We should make a aero thread. After the vented hood and splitter, I am sure we can get more. My car is perfect except pushes at 100 MPH + corners slightly.


Sent from my iPhone using Tapatalk

 

[Fabman]

What my main concern is actually how to add more front downforce. We should make a aero thread. After the vented hood and splitter, I am sure we can get more. My car is perfect except pushes at 100 MPH + corners slightly.


Sent from my iPhone using Tapatalk

A capitol idea....maybe @AJ Hartman would like to be part of this?