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Demystifying the ECU Tune | Fabspeed Motorsport

Posted by Dustin Panone on 26th Nov 2019

Demystifying the ECU Tune | Fabspeed Motorsport

Fabspeed Motorsport USA enjoys a long-standing history and reputation of designing and manufacturing the world’s best exotic car performance products. This includes our Engine Control Unit (ECU) performance modification products under the brand XperTune™ by Fabspeed.

This short paper explains the various ECU enhancements that Fabspeed provides to our customers, and some of the technical details that both our customers and Certified Performance Partners are often curious about.

So what is an ECU?

(for the experts, please forgive the oversimplification) Engine Control Units or Modules, even Engine Computers as they’re sometimes referred to, can be thought of as the conductor of a large orchestra, where the orchestra, in this case, is your vehicle.

In a musical orchestra, the conductor is constantly listening to, interpreting and guiding the various instruments to play their part of the score - at her command - on tempo, on the beat, and at the correct volume. The conductor also makes unnoticeable behind-the-scenes real-time adjustments to compensate for variations in say, background noise, and commands immediate changes to cover for errors such as a broken string on an instrument or a lost pick.

Without the oversight of the conductor, the musical performance would not be optimal.

Without the ECU, the performance of the vehicle would not be optimal.

The ECU is the conductor of the car’s engine system, and often many other subsystems of the vehicle such as transmission, driving mode and security. The ECU “listens” to many engine and environmental sensors. Like the many instruments found in the orchestra, and based on what the ECU hears or senses, it will command changes to various actuators on the engine itself.

For instance, the ECU senses oxygen content in the exhaust by various sensors, and it knows that a certain percentage of oxygen is ideal for best emissions and best performance. Should the ECU see a variation in what it expects to see as a percentage of oxygen, it will use those data to command an adjustment, of say the fuel rate entering the engine.

Early ECUs (1990’s) made it possible to increase MPG and reduce emissions, but they had a rather limited range of other functions. Later version ECUs collected data from even more sensors and could compute optimal fuel/air ratios, electronically control turbo boost, adjust ignition timing in millisecond intervals, and in some cases, command transmission shift actions.

Today’s ECUs are complex to the point that most everything about the drivability of the car, including its performance characteristics and safety features, is part of the dataset.

Since the ECU was developed, performance companies like Fabspeed engineered ways to alter the ECU’s internal computer programming to make vehicles perform better. Vehicle manufacturers generally do not appreciate when others modify their ECUs, but it’s a common practice that yields excellent, low investment results.

What is an ECU Tune?

For decades vehicle manufacturers relied solely on hardware design, like bore and stroke, variable cams, and turbochargers when they wanted to make more performance out of a core engine block. It was expensive for R&D and it was slow to produce new products. Today, with all of the technology like new metallurgy for smaller stronger parts, unique variable compression ratio systems, high temperature continuously adjustable vane turbochargers and the myriad other awesome advances, the software in the ECU is now the index and key to model performance and option upgrades.

Here’s an example: Instead of changing out the entire engine to make more power as an upgrade, vehicle manufacturers are simply changing the programming in the ECU from one model to the next. They often de-tune the engine via the ECU to have it make less power than it otherwise would and vice versa to make more power … while charging the customer large amounts for something as simple as flipping a switch. Not only is this cost-effective for them, but it is super easy.

At Fabspeed, we can do almost exactly the same thing - modify the ECU programming - by installing on the ECU a new “tune” of recalibrated software.

Our XperTune™ brand of ECU programming enhancements covers both older model vehicles and the latest in exotic cars. Fabspeed XperTunes, coupled with our free-flowing exhaust and intake systems, can unleash tremendous power gains, especially in turbocharged engines.

Before I explain the various tuning methods, a word of caution is in order. Adding more power to a car’s engine does have some risk. Depending on the condition of the engine, if old or poorly maintained, adding an aggressive tune could cause failure.

Even if the engine is solid, a performance tune places additional stressors on the transmission and drive system, which also may fail. On vehicles with a manufacturer's warranty in place, altering the stock ECU tune may void portions of the manufacturer's warranty.

Are all ECU tunes the same?

Short and sweet - No. At Fabspeed we produce tunes that have proven to be consistently reliable and exhilarating. While some tuning firms will go for broke and try to squeeze every last bit of horsepower out of the engine, we feel that’s short-sighted and dangerous.

It is not all about maximum numbers, it's about where you improve the numbers in the car’s drivability profile.

Fabspeed produces tunes that increase both horsepower and torque and at the same time make the car quicker, more even-keeled, and smoother to drive or race. We’d rather see a healthy peak of torque that grows steadily across the drivability profile rather than a sudden and essentially unusable spike of horsepower just to get “the number.” Those bucking, jerky tunes that may produce a slightly higher peak HP always sacrifice reliability and drivability and it’s advisable to stay far away from those brands.

It pays to research how the ECU will affect your car, and what you need to do, if anything, to use the tune reliability and safely. For instance, many ECU tunes will require that you run 93 “Pump” octane (98 RON) rated fuel or you may cause damage to the engine due to a phenomenon called detonation.

Briefly, the octane rating of fuel is a specification of how much that fuel can be tightly compressed before it ignites on its own. Fuel igniting in the cylinder on its own is a bad thing when it comes to engines. Higher compression engines and most turbo/supercharged engines will require higher octane fuel or they will audibly ping and knock; an event called detonation. In older less sound-proofed cars, if you hear these sounds as you accelerate hard, it means that the fuel is igniting unevenly in the cylinder(s) after the spark plug fires. This uneven ignition of the flame front causes pockets of gas to violently explode which creates great pressures that literally rattle the piston in the cylinder bore to the point you can audibly hear it. Using a higher octane fuel is a cure for simple organic detonation.

Is detonation different from pre-ignition? Oh ya - we’ll save that for another BLOG.

If you add an ECU tune to make more power from these engines, you may need to always buy higher octane fuel to avoid unintentional detonation damage. Modern cars have sensors that detect detonation and will de-tune the performance of the vehicle in real-time to protect itself from damage. You won’t even notice it’s happening, just like you didn’t notice the conductor of the orchestra covering for the cello string that she just saw fail.

XperTune™ by Fabspeed - the modern way to increase performance.

Fabspeed’s professional and racing ECU tunes - XperTune™ - comes in a number of formats depending on the vehicle and the intent of the tune. What I mean by intent is what the tune is expected to deliver.

For instance:

  • Are you looking for a noticeable increase in the performance of your daily driver and do not want to add any hardware, such as exhaust or intake modification? We have an XperTune for that.
  • You want a full high-performance system installed to make your street legal supercar as badass as it can be? Yes, we have an XperTune for that.
  • Just leased a new sports car? Want to kick it up a notch, but go back to stock with zero hassles when you turn it back in? Indeed, we have an XperTune for that.
  • And last but not least ...Do you want a track car with a Fabspeed racing exhaust system and free-flowing cold-air intake with Methanol injection? Oh ya, do we have an XperTune for that too!

Each of those above intents may have different tune formats. A tuning format is simply how you apply the new software tune file to your specific vehicle’s ECU. There are three ways:

  1. Fabspeed’s XperTune ECU Bench Flash
  2. Fabspeed’s XperTune Do-it-yourself Hand-held Programmer
  3. Fabspeed’s XperTune Performance Plug

Some cars may have all three options available, while others may only have one.

Each of the formats above have unique characteristics, varying degrees of installation time, and different performance boundaries. The good news is that our factory experts can walk you through the best option for your own unique needs.

For the curious, here's a quick summary of each:

ECU Bench Flash tunes require that you send to us your car’s ECU computer. When we receive the ECU we will add the software upgrades at our tuning facility using the latest technology and best practices. It may take as long as 24 hours plus shipping time to get the ECU back you and during that time your car is undrivable. This is the only option for some vehicles and may be the preferred option for highly modified vehicles because our tuning team can manipulate almost every parameter in the software. To return to a stock OEM tune, you must send the ECU back to us for reloading.

Do-it-yourself Hand-held Programmer is a user friendly device that you easily connect to your car’s OBD (On-Board Diagnostics) port. Once connected, the programmer will read data from your unique serialized ECU and store it on the programmer. You simply send us that data file via email, and we will send you an XperTune file back within 24-48 hours. Once you get the XperTune email, simply attach the programmer to the OBD port and upload your new performance tune - easy as pie! You keep the programmer forever, and if you ever wish to revert back to the stock OEM tune, you simply attach the programmer and load that software.

Performance Plug is not available for every car, and depending on the intent, even if it was available it may not be the best choice. The Performance Plug simply plugs into the connector that plugs into your ECU - that's it, you’re tuned! The Performance Plug analyzes and then alters the signals from the sensors that enter the ECU. By altering (or tricking) the ECU, more power can be made by fooling the system into believing it wasn’t doing its job in the first place. Cool idea that works pretty well, but there are limitations; we cannot directly influence many options in the ECU because we do not modify the actual ECU software. This choice is ideal for those who lease a sports car and do not want to add any other modifications, or your intent is to have a modest performance increase. To go back to stock, simply remove the Performance Plug and you’re done.

How do I learn more?

Easy, just call us! Fabspeed Motorsport USA has been and remains fully committed to increasing the performance and pleasure you get from your supercar. We support a worldwide network of Certified Performance Partners that not only make Fabspeed products available to you, but also expertly install them. For the DIY customer, we have a team of factory experts waiting to answer all of your questions and we’re happy to provide direct discounts to those who wish to install our products on their own. Best of all we have a Lifetime Warranty on Fabspeed brand exhaust systems along with our industry-exclusive Sound Solutions™ guarantee on our street performance systems. Please visit for more information.