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

Steeda Functional Wing 2014 MustangFrom all angles, the Steeda wing looks great without drawing too much attention.

Steeda Functional Wing Mustang S197We really do need to paint the wing but won’t have time between now and the track test.  But hey, the grey further matches the silver of the car! Haha.

Steeda Functional Wing 2014 MustangOur Project Budget 400whp Track Car now matches the aerodynamics of the BOSS 302R race car that I’ve won many races in professionally.  The Steeda wing has added significant braking performance, rear stability, and overall grip to the GS race car, and we are looking forward to the same benefits at the track.

Project Budget 400whp Track Car aero Steeda Wing Boss splitter

The BOSS 302 splitter balances the visual looks of our car as well as to slightly help offset the significant increase in rear downforce from the Steeda wing.

There is often a big misconception when it comes to aero that it “doesn’t work until _____ speed”.  Drag and downforce increase exponentially with the square of speed.  So, while there is a bigger difference at higher speed corners, there can still be a noticeable benefit in medium and lower speed corners.

Having raced FR500Cs with and without the Steeda wing, as well as various editions of the BOSS 302 from its debut to the 2013 refresh, the combination of the 2013 front bumper, with the BOSS splitter and Steeda wing had the most downforce and grip of them all, improved lap times, made the car easier to drive and took care of the tires longer by adding enough downforce to help keep the tire planted.

Is this aero package going to make you 5 seconds faster?  Probably not.  But adding hundreds of pounds of downforce to the car for such little money is definitely the best bang for your buck that’s out there and a must-have for any tracked S197.

Grand-Am GS History Lesson:

When the E92 BMW M3 started racing in 2011, it did not have the same E36 M3 LTW-style wing (made by Hamann) that the E46 M3’s had.  Without the rear downforce that these modest wings produce, the E92 M3s struggled with grip and were sliding around, killing their tires.  They remained uncompetitive until this same wing was grafted and homologated to be used on the E92 M3, at which point I think they won that very race if not the race after running the wing.

Meanwhile, there was a debate if the added downforce and drag of the Steeda wing was better at the high banks of the Daytona Roval.  Many Mustang teams opted to remove the wing thinking they would be faster without it at such a straight-line focused track as Daytona.  Roush knew better and we were one of the few Mustang teams to keep the Steeda wing on.  We also won that race and all the teams never tried racing without the wing after that.

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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