Project Budget 400WHP S197 Mustang Track Car: Part 8 – Aero with Steeda and Ford

2013 Mustang GT spoiler removedOnce cut through, we removed the spoiler to see the dirt buildup from the last 7 years.

2014 Mustang spoiler removed double sided tapeAfter cleaning up the dirt, it took a while to remove the double-sided foam from the bumper.  There’s no easy way to do this except a heat gun, your fingers, and the ensuing blisters.

2014 Mustang wing measuring mountWhile nursing our blisters, we found the centerline of the trunk and started to position where the wing was going to sit.

3D printed S197 wing mounting adapterSteeda offers a “Functional Rear Wing” that will bolt directly to the concave shape of the 2010-2014 Mustang decklid.  However, this wing has a “3-D” profile to it and is not the same wing that we raced in the Grand-Am series, or that we had in the wind tunnel.

I wanted to use the same Steeda wing that we raced, which was designed for the convex decklid of the 2005-2009 Mustang decklid.  To make this work on our race cars, we added material and re-profiled the base of the wing’s pedestal mounts.

For Project Budget 400whp track car – I put my CAD design and 3D-printing skills and tools to use and quickly printed out an adapter plate from PETG that matches the concave profile of the decklid and wing mount.  Later on, if PETG does not hold up to the Florida heat and humidity, I will print new ones out of ASA or Polycarbonate.

2014 Mustang GT Steeda wing mounting adapterWe positioned the wing as far rearward as possible, centered it on the car, and then marked the position of the wing adapters and mounting holes.

Quick Reference:

Page 1 – Overview
Page 2 – Boss Splitter Install
Page 3 – Installed Boss Splitter Review
Page 4 – Remove Stock Spoiler
Page 5 – Clean Decklid & 3D printed Adapter
Page 6 – Mount Steeda Wing
Page 7 – Review and Aero Insight


  1. Another good Billy Johnson article. If the used car market wasn’t so insane, I would be all over a ’13-14 Mustang and follow all your advice to modify it. I have only ever had miatas on track, so some power would be a nice change.

    1. Based off of the goals for the project to be a budget track car that’s also driven on the street without beating you up, and from my experience racing the S197 (with this aero) the Steeda spring and bar rates were chosen accordingly. Stay tuned for when I track test and evaluate this setup!

  2. Great articles, Billy! I can’t believe I came across this one just as I am trying to reproduce the aero package of the GS cars ever since I saw them at COTA in 2013. Most people like the WC cars, but I have a heart for endurance racing and I always wanted to duplicate the 302R. Anyway, I bought the Steeda wing years ago, but am only just now getting around to figuring out the mounting “shim.” I have contacted many of the race builders and nobody seems to have any left in a box on a shelf somewhere. I thought it would be awesome if somebody could just 3D print them and now – you have gone and done just that! Uh, any chance you can share that file? Any help would be appreciated. My website link goes to my write-up of the 2013 COTA race with a couple of pretty good pictures of your car.

    1. Would be even nicer if Billy could print up a half dozen or so of these at a time and make them available to purchase cor those of us with no 3D printing abilities.

  3. What is the part# of the Steeda wing you used? I looked on Steeda’s website and did not see this wing. They may not have the correct photo posted.
    The 3D printed adapters would be slick.

  4. I am getting ready to do the same things to my 2006 Mustang GT. Please let me know if you have the adapters available. Thanks for the article!

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