Ford Authority

The Optional Shelby GT350 Gurney Flap Explained

Among the various updates and changes to the 2019 Ford Mustang Shelby GT350 is an optional Gurney flap that the owner can remove and reattach to the standard wing via four bolts. It all sounds great in theory, but what the heck is a Gurney flap anyway? Here’s everything you need to know about the Shelby GT350 Gurney flap.

The name behind the Gurney flap harkens back to Dan Gurney, a great American driver. Just like Colin Chapman, who had his name associated with a suspension component (the Chapman strut), Gurney ranks among the few drivers to have invented something that had a significant impact on motorsports.

A gurney flap is typically installed at the trailing edge of a wing and usually aims upwards, like a duckbill spoiler. It may appear insignificant at first glance, but it’s a rather inexpensive and simple way to improve a car’s aerodynamic qualities. After it was installed with observable success on a Sprint car in the early 70’s, Gurney noticed in a wind tunnel that the flap affected pressure across the wing’s entire upper and lower surface, thus increasing downforce.

As simple as it may appear, the Gurney flap has drastic effects on airflow, especially at high speeds by creating two small vortices right behind the flap itself, both turning at opposite directions. Together, those two vortices create a rotating mass of air removed from the main flow, which leads to noticeable pressure on the rear of the car.

The Gurney flap is best suited for high-powered rear-wheel-drive sports cars (like the Shelby GT350), which require the maximum amount of grip from their rear tires, all while ensuring maximum stability at high speeds. What’s more, the flap doesn’t require much time to install or remove.

Today, the Gurney flap is used on many race cars, as well as on aircrafts, such as a helicopter’s tailplane, for example. And in the case of the 2019 Mustang Shelby GT350, it is part of a tuning overhaul to help the high-performance pony car improve downforce and be even quicker around the track by gluing the car to the ground during high-speed cornering, braking, and straight-line performance, thereby helping to improve lap times.

And that, ladies and gents, is everything there is to know about the 2019 Mustang Shelby GT350 Gurney flap.

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  1. David Butler

    Will Gurney flap work on a 2018 GT 350?

  2. Tyler

    I have purchased a 2019 GT350 with a Handling Package. The dealership has never seen this elusive Gurney Flap nor have they ever installed one. I called around to numerous Ford Dealerships in CA, KA, and FL. Not one dealership has ever gotten their hands on one and have only read about them. Why is this such a difficult thing to find and where is the Gurney Flap that I’ve paid for in the Handling Package. Please send me someone to contact that can point me and all of the dealerships in the right direction. Thank you in advance.

  3. Bryan

    How can I buy a gurney flap for my 2019 gt350 the dealership doesn’t even have a part number for this ….. they didn’t even know what the heck it was they just laughed at me until I showed them this article and they are still unable to get!!!

    1. Bryan

      Note I also called ford cust care and got pointed to their ford performance website which I have already researched ….. they as well couldn’t help!!

  4. justin

    I too cannot get ANYONE from Kansas to California who knows how to get it. I still waiting to see if anyone knows. Why is this such a mystery?!

  5. Jim Fries

    Hi I have one on order from the Ford dealer. It was on back order until July 26. It costed me a pizza for the guy at the dealership to find me the part number. I’ll let you know when I get it, on the price and part number.

    1. justin

      Awesome. Thx!

  6. jim

    If you like call me 215 5181664

  7. Jim

    Here it is spoiler # KR3Z-6344210-AA and # KR3Z-6344210-AB for gurney flap

  8. Fred B.

    My ‘19 GT350 came in 08/14/19. The Flap was in the trunk and was then attached by the dealership. Maybe they are more available now.

  9. JIM


  10. mike emmett

    The part is KR3Z-6344210-AA ITS 2710.00

  11. Fred B.

    The dealership also installed the adjustable strut mounts during make ready before I picked it up on Aug. 19th. It’s a beast.


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