Toyota SZ Tuning

"All you need to know about performance parts and tuning the Toyota SZ engine!"

Now we'll review SZ tuning and highlight the optimum mods that work. Toyota SZ are popular engines and with carefully picked motorsport mods like a remap, turbo kits and camshafts you will noticeably increase your driving experience.

The SZ is a joint venture between Toyota and Daihatsu all engines were manufactured in Toyota's plants in China and the Uk Deeside plant makes the Yaris units, but the 2SZ-FE and 3SZ-FE were also built in Daihatsu's Indonesian plant.

History, Power & Specs of the Engine

The SZ family was a joint project between Daihatsu and Toyota, and the aim was to create a compact engine that had good economy, reliability and reasonable power levels, it came in 3 generations with revised capacity each time.


1.0 L (997 cc). 16 valve straight 4 69.1 hp 70 lbft

  • Toyota Yaris
  • Toyota Echo
  • Toyota Vitz


1.3 L (1,297 cc 86 hp 90 lbft There was also a turbocharged version K3-VET

  • Toyota Yaris
  • Toyota Echo
  • Toyota Vitz
  • Toyota Belta
  • Toyota Ractis (XP100)


1.5 L 107 hp 104 lbft

  • Daihatsu Terios
  • Daihatsu Gran Max
  • Daihatsu Luxio
  • Daihatsu Sirion
  • Daihatsu Materia / Daihatsu Coo
  • Toyota bB
  • Toyota Passo Sette
  • Toyota Avanza
  • Toyota Rush
  • Perodua Alza
  • Perodua Myvi SE / Perodua Myvi Advance

Tuning the Toyota SZ and best SZ performance parts.

Best 1SZ-FE 2SZ-FE and 3SZ-FE tuning parts

The best 1SZ-FE 2SZ-FE and 3SZ-FE tuning parts on an engine are obviously the ones that give the best value for money.

We won't be swayed by popular 1SZ-FE 2SZ-FE and 3SZ-FE tuning parts, they need to be cost effective.

Significant gains on the 1SZ-FE 2SZ-FE and 3SZ-FE can be made from cam upgrades. Altering the cam profile alters the intake and exhaust durations on the engine and can dramatically change the engines power and power output.

Fast road camshafts usually raise the performance throughout the rev range, you may lose a little low down torque but the top end will be higher.

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

For a typical daily driver should ideally to match your power band to your cars usage.

I would be surprised if you find a 1SZ-FE 2SZ-FE and 3SZ-FE Race camshaft is a pleasure to live with when 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.

Some 1SZ-FE 2SZ-FE and 3SZ-FE engines respond better to mild camshaft durations than others.

The ecu map and injectors and fuel pump also have an effect on the torque gains you'll hit.

A longer valve duration can alter the torque 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. Engine Tunes - engine tuning/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.

Typical stage 1 mods often include: Panel air filters, Remaps/piggy back ECU, Sports exhaust header/manifold, Fast road camshaft, Intake manifolds, drilled & smoothed airbox.

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

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

Plan your options and then acquire your parts and set yourself a power target to save yourself from expensive mistakes.

Remaps allows a tuner to release the full potential of all the upgrades you've fitted to your 1SZ-FE 2SZ-FE and 3SZ-FE.

(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 power output often rely on the upgrades you've applied and the condition of your engine.

It is the aim to any tuning task to feed more air into each cylinder

Air Intake manifolds transmit the air from the intake filter and allow it to be fed into the engine cylinders with fuel for the squish phase.

Design and flow characteristics of the Intake manifold can make a large effect on to fuel engine efficiency on the 1SZ-FE 2SZ-FE and 3SZ-FE.

I usually find plenum chambers are needing aftermarket parts, although a few car makers provide decently flowing plenum chambers.

Increasing the 1SZ-FE 2SZ-FE and 3SZ-FE valve size, doing a bit of port work and head flowing will also boost bhp, and as an added benefit will raise potential for increasing the bhp increase on other mods.

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 1SZ-FE 2SZ-FE and 3SZ-FE

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

If your motor is turbo charged mods are more reliable and you will discover turbo charged engines are made with uprated components.

However engines will have power limits

See where you'll find these restrictions and upgrade to higher quality components to utilize the power.

We've seen guys spending a a stack of money on turbo charger upgrades on the 1SZ-FE 2SZ-FE and 3SZ-FE only to see the engine block throw a rod on it's first outing after it's been enthusiastically driven.

Larger upgraded turbos tend to experience no power at low rpm, and smaller turbos spool up quickly but don't have the peak rpm bhp gains.

In the last 10 years the range of turbochargers is always evolving and we now see variable vane turbochargers, permitting the vane profile is altered according to speed to lower lag and increase top end bhp and torque.

Twin scroll turbochargers divert the exhaust gases into 2 channels and feed these at differently designed vanes in the turbocharger. They also increase the scavenging effect of the engine.

It is common that there's a limit in the air flow sensor (AFM/MAF/MAP) on the 1SZ-FE 2SZ-FE and 3SZ-FE when considerably more air is being pulled into the engine.

We note 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 challenging to get working. We have this feature on twinchargers if you want to read more.


Don't dismiss the need raise the fuelling when you are increasing the bhp - it makes the car more thirsty. It makes sense to be generous with your injector capacity.

The rule of thumb is to add 20% when fitting an injector, this allows for injector deterioration and gives a bit of 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.

All the following flywheel power targets will assume an injector duty cycle of 80% and a base of 58psi of fuel pressure at idle.

4 Cylinder turbocharged engines

  • 58 PSI 340cc/min 200hp

4 Cylinder NA (naturally aspirated) engines

  • 58 PSI 285cc/min 200hp


You may need to improve your exhaust if the current exhaust is actually creating a flow problem.

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

Note that with the widest exhaust you can source you'll slow up the exhaust flow rate - the best for power gains are usually between 1.5 to 2.5 inches. It is the shape and material more than the bore size.

Usual exhaust restrictions are traced to the emissions filters installed, so adding a higher flowing sports alternative is the answer. This keeps the car road legal and will flow much better due to it's higher internal surface area and design, so has the added benefit of keeping your car road legal. The alternative decat should be considered an off road only mod, as removing a catalyst is illegal in most territories and regions for road registered cars..

Weak spots, Issues & problem areas on the 1SZ-FE 2SZ-FE and 3SZ-FE

The 1SZ-FE 2SZ-FE and 3SZ-FE 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 1SZ-FE 2SZ-FE and 3SZ-FE, especially when tuned and will help extend the life and reliability of the engine.

The pistons have been known to tilt causing wear to the engine cylinder walls with symptoms including high oil consumption, burning oil and knocking.

If you would like to know more, or just get some friendly advice on Tuning your 1SZ-FE 2SZ-FE and 3SZ-FE engine please join us in our friendly forum where you can discuss tuning options in more detail with our 1SZ-FE 2SZ-FE and 3SZ-FE owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

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