Fiat Firefly T3 Tuning

"All you need to know about tuning the Fiat Firefly T3 engine!"

The Fiat Firefly T3 make a good tuning project and with a few sensible tuning upgrades like a remap, turbo upgrades and camshafts you will dramatically increase your driving experience.

We shall detail the best approach to Firefly T3 tuning and outline the greatest modifications.

History, Power & Specs of the Firefly T3 Engine

Also known as the FCA Small Global or GSE engine this range had a modular design allowing Fiat to offer it in a variety of power levels and states of tune.


  • 120 PS (88 kW; 118 hp) at 5750 rpm 190 Nm (140 lbft) at 1750 rpm


  • Jeep Renegade FL
  • Fiat 500X FL

Tuning the Fiat Firefly T3 and best Firefly T3 performance parts.

Best Firefly T3 upgrades

The ultimate Firefly T3 upgrades on an engine are as we have found the ones that give the biggest return for your cash.

We won't be swayed by popular Firefly T3 upgrades, they need to be cost effective.

Altering your Firefly T3 camshaft will make a dramatic difference to the engine engines power. Choosing a higher performance camshaft profile raises the engines power accordingly.

Fast road camshafts commonly bump the power over the rpm range, you may sacrifice a little low end power but your high end rpm power will be lifted.

Motorsport and race camshafts, bump the high end rpm power band but as a result the car will not idle smoothly and low end power nearly always suffers.

A Motorsport cam won't do well if on the daily commute, because the lumpy idle will make the car prone to stall and smooth driving at low rpm becomes impossible. If you are developing a track car this doesn't matter as you are in the high end of your RPM range anyway and that is where you want the power to be.

You should ideally match your engines power to your typical driving style so for a car driven daily stick with a fast road Firefly T3 cam

Some Firefly T3 engines respond better to more aggressive cam durations than others.

The engine timing and fuelling also have a large bearing on the power gains you'll achieve.

Altering valve durations can alter the power band and on most engines the exhaust and intake durations do not need to match, although most cams and tuners use matched pairs there are some advantages to extending the intake or exhaust durations.

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Best Engine Mods for your car

  1. Mapping - remapping provides the most advantage in terms of cost savings,  aftermarket ECUs, and piggyback ECUs are all alternatives.
  2. Fast road cams are one of the most significant mechanical changes, but they must be installed by someone who knows what they're doing and they are not always easy to source but you might find a local firm to regrind a stock camshaft.
  3. Intake and Exhaust - Note that on their own these mods will NOT ADD POWER in most cases, but they can help enhance power after other mods by removing the restriction.
  4. Upgrades to turbochargers and superchargers - forced induction is the most efficient approach to increase air supply, allowing you to burn more fuel and make more power. It is one of the most costly upgrades but provides the best gains.
  5. Head work - The goals of porting and flowing the head are to get air flowing into the engine while removing flow restrictions and turbulence.
  6. Typical stage 1 mods often include:
    Fast road camshaft, Panel air filters, Intake manifolds, Sports exhaust header/manifold, Remaps/piggy back ECU, drilled & smoothed airbox.

    Typical stage 2 mods often include:
    Sports catalyst & performance exhaust, induction kit, fuel pump upgrades, Fast road cam, Ported and polished head, high flow fuel injectors.

    Typical stage 3 mods often include:
    Adding or Upgrading forced induction (turbo/supercharger), Engine balancing & blueprinting, Crank and Piston upgrades to alter compression, Twin charging conversions, Competition cam, Internal engine upgrades (head flowing porting/bigger valves).

    The Firefly T3 units make great tuning projects and thankfully there is an increase of mods and performance parts out there.

    Remaps allows a tuner to fully realize the full potential of all the parts you've done to your Firefly T3.

    (In some cases, as the factory ECU is locked flashing is not an option, so an aftermarket ECU is the route to take, and many of these will outperform factory ECU's but make sure it has knock protection and that you get it setup properly.)

    It will usually give you around 30% more power on turbocharged vehicles and you can expect to see around 15% on NA (naturally aspirated) engines, but your results will vary depending on the parts you've done and the condition of your engine.

    It is the aim to any engine upgrade project to shove more fuel and air into your Firefly T3

    Air Intake manifolds take the air from the air cleaner and allow it to be sucked into the engine cylinders.

    Structure and rate of flow of the Intake manifolds can make a big difference to fuel atomisation on the Firefly T3.

    We often see manifolds are begging for an upgrade, although some makers provide reasonably good headers.

    Fitting big valve kits, doing a bit of port matching and head flowing will also boost power, and more importantly will raise potential for a greater power increase on other mods.

    Firefly T3 Turbo upgrades

    NA (naturally aspirated) engines need quite a lot of work when you add a turbo, so we have a separate guide to help you take into account the pros and cons of going this route on your Firefly T3

    The more air you can get into an engine, the more fuel it can burn and uprating the induction with a turbocharger upgrade makes superb power gains.

    If an engine has forced induction tuning mods are more reliable and turbocharged engines already contain better components.

    However every engines will have power limits.Discover these limitations and install forged components to survive the power.

    It's not unheard of drivers spending a loads on turbo charger upgrades on the Firefly T3 only to have the whole thing throw a rod on it's first outing after it's used in anger.

    Large capacity turbo chargers often suffer a bottom end lag, and low capacity turbo chargers spool up more quickly but don't have the peak end engines power gains.

    Thankfully the selection of turbochargers is always developing and we are seeing variable vane turbochargers, where the vane profile is altered according to speed to lower lag and increase top end performance.

    Twin scroll turbochargers divert the exhaust flow into a couple of channels and feed these at differently designed vanes in the turbo charger. They also help the scavenging effect of the engine.

    It is common that there's a restriction in the air flow sensor MAF/MAP on the Firefly T3 when a lot more air is being drawn into the engine.

    We see 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor sapped bhp at a much lower level.

    Adding a supercharger or additional turbo will make large bhp and torque gains, although more difficult to setup. We have this article on twincharging if you want to read more.


    When you raise the torque you will need to uprate to the fuel delivery.

    More torque needs more fuel. It is important to over specify your injector capacity.

    The accepted safe increase is to add another 20% when fitting an injector, this accounts for injector deterioration and allows you some spare capacity should the engine require more fuel.

    We think this one is common sense, but you'll need to match your fuel injector to the type of fuel your car uses as well.

    Firefly T3 Performance Exhausts

    You only need to improve your exhaust if the current exhaust is actually causing a restriction in flow.

    On most factory exhausts you'll see your flow rate is ok even on modest power gains, but when you start pushing up the power levels you will need to get a better flowing exhaust.

    Sports exhausts generally help improve air flow through the engine but do not go too wide or you could very well end up with a reduced flow rate. So generally speaking, keep to 1.5 to 2.5 inches for best results.

    Common exhaust restrictions are traced to the emissions filters installed, so adding a faster flowing race alternative such as a sports catalyst pretty much removes this restriction, thanks to it's larger size and surface area, and will effectively raise the performance to levels you would expect without having a catalyst installed, but keeps the car road legal.

    Weak spots, Issues & problem areas on the Firefly T3

    The Firefly T3 engines are generally reliable and solid units, as long as you follow the manufacturers service schedules, and use a good quality oil to ensure longevity. Few problems should happen as long as they are regularly serviced and maintained.

    Carbon build up in the head, particularly around the valves which will sap power or create flat spots, this is a larger issue on direct injection engines but should be looked out for on all engines. We have tips on removing carbon build up.

    Some of our members have had issues with flat spots or glitches after applying mods and upgrades or tuning, this is not usually related to this engines design, so instead see our article on diagnosing flat spots and problems after tuning which should help you get the bottom of this issue.

    Regular oil changes are vital on the Firefly T3, especially when tuned and will help extend the life and reliability of the engine.

    If you would like to know more, or just get some friendly advice on Tuning your Firefly T3 engine please join us in our car forums where you can discuss Firefly T3 tuning options in more detail
    with our Firefly T3 owners. It would also be worth reading our unbiased Fiat tuning articles to get insights into each modification and how effective they will be for your car.

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