Almost.
That’s all it took to join the gang. Now it’s time to experiment with my wang. Now that I have a nice one, it’s going to be tempting to play with it a lot. But you want some method to your madness. If you just play with it all the time you’ll go blind from trying.
Nine Lives Racing recommends starting with a wing angle of anywhere from 0-7 degrees of attack. If you have a smartphone, find an angle app (I used “Bubble Level” on Android) that allows you to calibrate. Otherwise get some kind of level measuring device (those circular ones work pretty good) at the hardware store. Park your car on a reasonably level surface, and calibrate your phone (or other tool) against the ground for zero.
Then, rest your phone along the top of the endplate so that you can measure the angle of the wing. Adjust which of the multi mounting holes you use until you find the desired angle. Be sure that you use the same mounting hole on each side of the wing. If you don’t pay attention it’s easy to end up with a crooked wang. And a crooked one generally doesn’t work as well.
This likely is not a precise measurement in respect to the real world, but if you do it this way every time it will be reasonably accurate enough to know how to make changes going forward. Drive the car, and see how it feels. This part is unfortunately trial and error. The goal is balanced handling — not too much push or oversteer. Having a data logger like my Autosport Labs RaceCapture/Pro will sure help — once I get back out on track!
Just gotta make some vehicle safety system updates, and then 2020 here we come!
5 comments
Dang, I was hoping that the paint would be use for flow visualization. Flow viz paint, and wool tufts are both cheap and effective methods to develop chassis aerodynamics.
You can’t really know what the flow is like at the back end of a vehicle without real-world testing. For example, the optimum solution for the SC300 may not be a wing, at all…but rather, a trunk lid spoiler. You can gain both downforce anb reduce drag if you design a proper spoiler. The curved surface of the SC300 rear trunk lid probably increases lift, rather than making downforce. So, there’s a huge missed opportunity by installing a rear wing only.
Personally, I would like to see more testing, and real-world verifcation before I were to commision the fabrication of a solution like a custom rear wing.
Please note, that some of the most expensive super cars currenly being produced no longer include rear wings. This is because a wing is not the optimal method to produce downforce. A diffuser/spoiler is currently en vogue because it produces downforce with very small drag penalties. A proper race car optimizes the negative lift/drag coefficient.
One should always explore as many solutions as possible before committing to one particluar solution.
I don’t want to be a complete Debbie Downer, but I would highly recommend that you use some flow viz, and install a lip spoiler on the trunk lid. (The flow viz can be used before/after to verify the solution.) A rear lid spoiler will make the rear wing and rear diffuser more efficient. Whenever you can get a two for one, that’s when you know that you are heading down the right path.
A properly designed and placed wing is the lowest drag to downforce device.
Aye, a wing is definitely the most efficient item by itself. But you can get quite significant interaction by changing the pressure distribution on a large area of the car, which is how you get crazy high lift/drag ratios like were seen in Group C racing, even with the primitive state of CFD at the time (pretty much 100% wind tunnel testing to develop those cars).
An SC300 would probably see quite a benefit by putting a small lip spoiler on the end of the trunk lid. This will encourage clean separation of flow at the rear end of the car (look at modern cars now, they all have sharp features at the very back for this reason), and at a moderate ~15-30 deg angle and ~1.5-2″ of height, it will tend to reduce total drag and add a small bit of rear downforce. We’re not talking huge downforce here, but it reduces drag at the same time, so it comes at no aero penalty.
Was some type of photogrammatry used (stitched 2d photos from normal camera), or was a true 3d capture camera used?
@cmj re-read page two:
“But there’s an end to this means, I assure you. And it’s not another innuendo. I don’t think. If you look back to the photo of Rob, he’s taking a photo. In fact, he’s taking dozens of photos. You see, when you take dozens of photos from different angles of the speckled car, you can then use some really fancy computering to stitch all of the photos together to build a really accurate 3D model of the vehicle.”
https://motoiq.com/project-sc300-road-racer-part-27-joining-a-wang-gang/2/
Rob is using a regular digital camera and then stitching 2D photos together using software to build the 3D model.