DIY Spoiler

[JohnnyBomber101]

Okay, I have not been able to find a spoiler online that I like enough to spend several hundred dollars on. So, i decided I would make one myself.


I contacted Derrick at DJRacecars out of London and we had a little mental pow-wow over the best spacing and horizontal spacing for a truly effective wing for a Yaris. These guys have done a lot of Lupos, Citreons and Opels for every level of racing you can imagine. Their rally bodies are really awesome.

Anyway, his opinion was that the "best" placement would be slightly below (3-4mm" the actual termination of the roof line at the hatch. The company has done extensive work with Mitsubishi designing the ever so slight changes in the rear vortex generators on the MR series of the EVO. He sent me a cool pic showing what they do and why. Utilizing the generators on a notchback sedan almost negates the need for a spoiler unless the positioning of the leading edge of the foil is in the correct place. You can see from the pic that the factory spoiler is not needed on a car equipped with the generators.

On the Yaris, my intention is to use both the generators and the spoiler. By flattening out the airflow and feeding it directly on the wing, a tremendous amount of force will be able to be created that will only increase with speed.

So, let's talk about the wing. Because the shape of the car has an inherently low co-efficient of drag, a dive plane and leading edge will not be necessary. I am simply going to round the leading edge off and leave it flat. The top plane will be flat and the control surface (aileron) will be a uniform, full length upward bend at 31degrees. Why 31? Because that is the "magic" number that mother nature decided on when figuring LEMAC and MAC. Plus, there technically will not be a chord to the shape because we are not trying to create a pressure differential.

Materials:

6" x 40" 5052 Aluminum plate (5" flat with a 1" aileron)
3/4"x3/4"x3/16" 6061 Aluminum L channel (36" long piece)
12"x12"x3/16" 7075 Aluminum Plate

I drew the patterns for the brackets and the endcaps last night and I built a prototype out of cardboard. Check it out: