Project SC300 Road Racer: Part 27 – Joining a Wang Gang
many sheets of aluminum with shapes cut out and leaning against wall
Nine Lives Racing may have made a few sets of wangs and pylons and things…

 

small aluminum plate being run on routing table, 9 lives racing logo visible and lots of mounting holes
Here Johnny is finishing up the mount that goes underneath the wing by cleaning up the edge.

Johnny does a good job of reminding you whose products are being used!

 

two mounting plates stacked up and sitting on top of aluminum wing body
Here’s the final product – two mounts that will be welded directly to the underside of the airfoil.

 

measuring tape running along wing body with hands marking with a permanent marker
Johnny has a jig that he uses for precisely and accurately welding the mounting tabs to the wing.

The first step is to consult the engineering drawings to determine the placement of the tabs, and then mark the spot for the jig to hold them.

 

jig and welding-gloved hand holding mounting plate against wing body
With the mounting tab held in place by the jig, it’s time to melt some metal.

5 comments

  1. 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.

  2. 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.

    1. @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.

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