The 2018 Mustang GT’s Gen 3 Coyote 5.0-liter engine is a true wonder. It features a number of updates that allow it to produce 460 horsepower off the dealer lot and much more when modded. However, among its updates is one that could limit the engine’s true breathing potential if it weren’t for the clever crew at JMS.

They allow you to reliably install any larger analog throttle body onto a 2018+ 5.0-liter Ford engine. — Chris Johnson, JMS Chip USA

While the throttle body on the latest 5.0-liter engine resembles its predecessor, Ford engineers changed the strategy it uses to communicate with the factory powertrain control module. Where the previous Coyotes employed a simple analog strategy, the 2018 Mustang utilizes the modern Single Edge Nibble Transmission strategy, which is digital.

There is powerful tech in this compact, easily installed box. The JMS ThrottleSwap simply plugs in between your factory 2018+ F-150 or Mustang harness and a GT350 or GT500 throttle body. This allows running a larger analog throttle body designed for earlier PCMs on the latest Coyote engines. The ThrottleSwap is also compatible with JMS’ other plug-in performance enhancers, like the PedalMax, which hastens the throttle response on drive-by-wire vehicles.

“The throttle body strategy is essentially the same,” Chris Johnson of JMS Chip USA, explained. “The transport medium that provides the information about the throttle position has changed. Up until now, the throttle position information was transmitted to the ECU via two analog 0- to 5-volt channels.”

That’s all fine and dandy until you want to install a larger throttle body. Many of the popular options are sourced from earlier Mustangs, namely the Shelby GT350 and Shelby GT500 and its aftermarket replacements. The GT350 offers a 87mm diameter, while the GT500 throttle body replacements offer far larger openings. That’s great, except both utilize a strategy that is incompatible with the 2018 F-150 and Mustang PCMs.


“The GT350 and GT500 analog throttle bodies have different 0- to 5-volt output signal ranges,” Chris explained. “We also offer a version to install a regular 2015-2017 Mustang GT throttle body on a 2018 5.0-liter and a version that will allow a 2010-2016 3.5-liter analog F-150 throttle body on a 2017+ 3.5-liter F-150 with the digital throttle body.”

For the needs of Coyote fans, JMS offers two ThrottleSwap converters — one for the GT350 throttle body and one for the GT500 throttle body. These will allow you to add more airflow to naturally aspirated and supercharged combinations.

Whether you want to run an 87mm Shelby GT350 throttle body or a Shelby GT500 oval throttle body, JMS has a ThrottleSwap converter that makes the swap easy. Matt Alderman of ID Motorsports used it successfully to run a GT500 throttle body and a Cobra Jet intake a his 2018 Mustang, which put down over 500 horsepower to the wheels in naturally aspirated form. (Photo Credit: ID Motorsports)

“They allow you to reliably install any larger analog throttle body onto a 2018+ 5.0-liter Ford engine,” Chris explained. “We also have other versions of the product. One version allows you to install a larger GM or Ford analog throttle body on a 2016+ LT1 GM Engine, while another version allows you to install a GM SENT throttle body on a Ford SENT vehicle and vice versa.”

Basically, if you want to install a throttle body on a newer vehicle, JMS has you covered. Fortunately for Matt Alderman at ID Motorsports, as he needed the ThrottleSwap to facilitate the Cobra Jet intake swap on his 2018 Mustang GT. For the initial testing of this combo he opted for a factory twin 60mm Shelby GT500 throttle body, but he has also installed the GT350 unit on other applications.


“We had to use two different boxes mainly for the plug-in. The GT500 had the TPS and motor on separate ends of the throttle body, while the GT350 has it all incorporated into the factory style single six-wire connector. Being that we had to change the way we calibrate for the different throttle bodies,” Matt said. “Without the boxes we could not convert the signal from digital to analog. The new circuit has five wires going to the throttle body instead of six as previous logic.”

With the ThrottleSwap plugged inline between the factory harness and the new throttle body, the factory PCM can control it just as it would the stock unit. However, with a larger throttle body in place a new calibration is still necessary to ensure the additional airflow is recognized.

If you want to let more air into your Gen 3 Coyote engine, like ID Motorsports did, you are going to need a JMS ThrottleSwap to make it work.

“Even with the converter box we still need to calibrate for the throttle body we are using. We have to hit all the areas in the calibration, like Effective Throttle Area, Open Loop Feed Forward Throttle Angle, and Sensor Slopes to name a few,” Matt added.

If you caught our story on his Cobra Jet intake swap, you know the results were quite effective, but the JMS ThrottleSwap opens the door to all manner of throttle body, intake, and supercharger combinations, and you can learn more about the product here.