What is ECU tuning? How does it work, what does it do?

ECU tuning is tweaking the computer that controls your engine to increase performance. In most cars, this involves “flashing” or reprograming the ECU software, but with the Fiat 500 Abarth the most common application is a “piggyback” module which is a piece of hardware installed on your car that can then tweak the settings to increase horsepower.

Jump to the list of Fiat 500 Abarth ECU tunes!

An ECU tune can adjust boost pressure, timing, etc. to increase throttle response, torque, and overall horsepower. FIAT, just like all car manufacturers, has to account for things like low octane fuel, emissions, efficiency, reliability, and budget and usually limit the power of an engine to stay within those constraints. While most good tuners will stay within the limits of the engine and can even increase MPG, they don’t have to meet the rules and regulations of a car manufacturer.

The Fiat 500 Abarth MultiAir Engine

Is ECU tuning risky? Will it void my warranty?

While just installing an ECU tune will not void your warranty, there is definitely a chance that FIAT will deny a warranty claim for a repair on something related to the ECU if they find out you had a tune installed at the time. If that truly worries you, it would be best to wait until your car is out of the factory warranty.

Beyond the risks of being denied warranty coverage, there is potential, although minimal, that the reliability of your engine will be reduced with an ECU tune installed. If you’ve ever built a computer, you know that just like engine ECUs, CPUs from AMD and Intel can be “overclocked” to squeeze out more performance. But, this typically lowers their lifespan and without enough cooling in place they will burn out very quickly. An ECU tune for your car won’t overheat the engine, but it can reduce the lifespan of related parts over the long term.

For example, with the extra power you’re going to put more wear on the clutch. It’s also a bit of a compounding problem, because with the ability to go faster, you’ll end up braking harder and causing more wear on the breaks. You’ll probably end up driving more, which will cause more wear and tear on everything.

But, for almost all tunes we’re only talking about 30-40 more available horsepower and there is only extra stress on the engine if you use it. If you already have a lead foot anyway (which I assume you do if you’re researching aftermarket ECU chips), then you’re probably going to see a lot of wear regardless. Almost all tuners still stay within the limits of the engine though, so when I say “reduce the lifespan”, I’m talking about talking about after thousands, if not hundreds of thousands of miles.

Why is ECU flashing rare for the Abarth?

On the Fiat 500 Abarth, the ECU controls the inlet valve system on the MultiAir engine. This is more than most ECU tuners are willing to tinker with, as it could lead to a broken engine. Most of the currently available tunes, including one by FIAT’s official tuner Magneti Marelli, are technically a “piggyback” system instead of a direct flash like other aftermarket chips on other cars. But as just the owner of the car, this shouldn’t make any difference to you. The results are still the same.

How much power can be gained from ECU tuning?

The base Fiat 500 Abarth engine in the US comes stock from the factory with 160 horsepower and 170 lb-ft of torque. Depending on which chip you choose, you can achieve anywhere from 180 to well over 200 horsepower without any other mods. With additional mods and some of the more customizable tunes, there’s potential for 230+ horsepower.

Keep in mind that not all tunes are developed the same and not all peak horsepower figures feel the same. Power gains aren’t completely linear. Different tuners have different power bands, so the highest claimed horsepower may not feel the fastest on the “butt dyno”. It all depends on where you use your power the most. For example, for street light to street light, you’ll want a lot of power at the lower end. But for those high speed highway passes or weekend track days, you’ll probably want more top end power. Be sure to study the dyno graphs from each tuner, read reviews, and decide which tune would be best for your daily use.

Fiat 500 Abarth ECU Tuner Comparison

Magneti Morelli

Price: $699 (purchase)
Power: +40 horsepower, +? torque

  • activates only after engine reaches operating temperature
  • deactivates in case of “abnormal and prolonged elevated engine temperatures and overheating”
  • gold plated pins for zero leakage from electrical connections
  • preloaded with two tunes: Performance and Race/Venom

MM are the most well known, since they are the in-house tuner for FIAT. 500 Madness dyno’d the MM ECU and saw 196.5 total horsepower. Depending on which mode you put it in, it can add between 25-40 horsepower. The prototype for this was used on the 200HP Fiat 500 Abarth Venom concept car.

The unit will come preprogramed with the 0-stock, 45%-Performance and 58%-Race/Venom Tune. If you are using the Radio Remote Control you will be able to switch back and forth between the settings as you like. If you are getting the unit without the remote control your unit will be set to the 58%-Race/Venom Tune.


TMC Motorsports

Price: $499 (purchase)
Power: +60 horsepower, +51 torque

  • 3 year warranty
  • transferable to another Abarth
  • adjustable power setting
  • can be removed in minutes
  • included by pass plug allows removing box without removing harness

TMC Motorsports has created a “digital tuning kit” for the Fiat 500 Abarth, which is essentially the same as a piggyback ECU. 500madness.com claimed dyno results of 187.6 HP. Officially, TMC Motorsport only claims up to 40% increase in BHP and 30% increase in torque.


UNI-CHIP by Eurocompulsion

Price: $650 (purchase)
Power: +45 horsepower, +60 torque

  • future upgrades available via download
  • standard UniChip features: map boost, drive extra injectors, data-logging, etc.
  • plug-n-play style means it can be removed in minutes with no evidence

This is another piggyback module that can be installed/removed in just 15 minutes, but unlike most other options it allows you to tune the car yourself. The UniChip can hold up to 5 tunes, which you can download from UniChip or enthusiasts in the Abarth tuning community. For some, this provides all the benefits of a full ECU flash, with the ability to easily remove it. This is especially useful when you want to try a different ECU chip, or take it to a dealer for service, or sell the car.


Road Race Motorsports

Price: $599 (purchase)
Power: +30 horsepower, +50 torque

  • can be combined with Methanol injection
  • boost is held at 20+ PSI
  • cannot be overwritten

Road Race Motorsports now offers their own chip, called the Ultimate, which they developed completely from scratch and claim it offers the most power of any option on the market. With complimentary mods, they are claiming up to 250 horsepower is possible! Here’s a review from a customer:

I stomped on the “go faster” pedal. Holy $#1t is all I can say. In 4th gear, I stomped on the pedal on the freeway and before I could blink I had already shifted into 5th gear and had surpassed 100mph. I was shocked at the ferociousness of the car. It just hauls a$$.


Tork Motorsports

Price: $495 (purchase)
Power: +40 horsepower, +60 torque

  • rev limiter increased
  • improved MPG
  • throttle lag removed
  • turbo surge removed
  • optional launch control
  • optional WOT shift control

Tork is one of the few companies offering an ECU flash and not just a piggyback module. The downsides to this are that you have to send in your current ECU via mail, so your Abarth will be down for at least a couple days, and the dealer could technically overwrite the tune if there’s ever a reason to update the ECU (unlikely). Tork offers a stage 1 tune which adds 40 WHP and 60 WTQ with typical results of “190 to 200 WHP and 215 to 240 WTQ”. Here’s how they describe the tune:

Power! Yes the car makes more power but we don’t justify the additional power by running dangerous boost levels or excessive lean condition… we make the power with proper application of Multiair tuning, timing adjustment for premium fuel, torque limits raised and fueling. We retain all the factory safety limits for boost, over-temp, over torque, wheel spin with brakes applied, etc. Our focus with the Stage 1 tune was simple, offer what it should have been from the factory.

You can see the install process here:

And the resulting test drive here:


Whichever choice you make, you’ll likely be happy with the increased power. Have you tried any of these options above? Or heard of something else? Let me know in the comments.