DIYAutoTune Case Study

1967 Camaro Race Car with MS3Pro EFI being tuned on MS3Pro with USB-2920 USB to Serial Adapter


  • Allow users’ laptops or other devices to communicate with their purchased ECUs.
  • Provide a compatible adapter for a reliable connection with ECUs.


  • Ensure a reliable connection to read real-time engine tuning data via TunerStudio.
  • Provide a solution to become the standard USB to RS-232 DB9 adapter offering.


  • Deliver a compatible, reliable, and cost-effective USB to RS-232 adapter for use with DIYAutoTune’s ECU offerings.


ECU collage

DIYAutoTune’s plug-and-play Engine Control Units (ECU) supply automotive enthusiasts with tuning and data logging to fine tune their engine. After a quick installation, users are on their way to finding real time tuning data via a serial connection.

For non-legacy laptops, computers, and other host systems that do not include a serial port, a USB to DB9 serial adapter is required. Not any USB to RS-232 serial adapter can be used however. DIYAutoTune consistently found that when customers contact them with communication issues, it stems back to a cheap adapter with a Prolific chipset.

DIYAutoTune required a compatible, reliable, and cost-effective USB to serial adapter to offer to their customers in conjunction with their plug-and-play ECU offerings.


After testing multiple serial adapters, the one that came out on top featured an FTDI chipset. An adapter that for over 13 years now, has worked flawlessly with DIYAutoTune’s ECUs.

That adapter? The 765288 USB to Serial RS-232 DB9 FTDI Mini Adapter from Coolgear’s partner, CableMAX. When connected to one of DIYAutoTune’s ECUs paired with TunerStudio, a prominent tuning software, this adapter communicates a constant stream of real-time tuning data straight from the engine to a host computer.

The included FTDI chipset offered the best results for years and allowed the 765288 adapter to become a staple offering on as a suggested accessory under the model number: USB-2920. Just as DIYAutoTune’s ECUs are plug-and-play, the CableMAX USB to serial adapter often installs FTDI drivers automatically and is ready for use. For any outliers, a quick visit to FTDI’s driver download page offers a quick solution.

DIYAutoTune logo

Industry: Automotive

Location: Gainesville, GA

About: DIYAutoTune is the home for all of your Do-It-Yourself (DIY) automotive tuning needs. They supply everything needed to install your own fully programmable Engine Management System on almost any engine.


The CableMAX USB to DB9 RS-232 serial adapter stayed consistently compatible with DIYAutoTune’s plug-and-play EMC products for over 13 years.

DIYAutoTune’s ECUs and EMSs, and further CableMAX’s serial adapter, have seen use from project cars to sponsored race cars. Through the USB to DB9 connection, users can read data to fine tune fuel and ignition control for just about anything with an engine including cars, trucks, motorcycles, boats, snowmobiles, and more.

1967 Camaro Race Car with MS3Pro EFI being tuned on MS3Pro with USB-2920 USB to Serial Adapter

The Product

USB to Serial RS-232 DB9 FTDI Mini Adapter with Extension Cable

CableMAX Model No. 765288

This USB Serial FTDI-based adapter converts a USB port into a serial port capable of speeds up to 921,600 bps.

  • Protect Your Equipment: The adapter supports 10KV ESD surge protection to keep your connected peripheral safe from harm.
  • Wide Compatibility: Windows 7, 8, 10, & Windows 11 as well as Linux and Mac OS 10.X.
  • Extension Cable: A detachable 2ft. standard USB-A male to A female extension cable is provided.
View on DIYAutoTune View Coolgear's USB to Serial Adapters
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