Toyota 5A Tuning

"All you need to know about performance tuning the Toyota 5A engine!"

The Toyota 5A make awesome project engines and with carefully picked uprated parts like remapping, turbo improvements and camshafts you will really maximize your driving experience.

Our aim here is to review 5A tuning and point out the best modifications for your car.

History of the Engine

The 5a launched in 1987  and production ran to 2006. it came with DOHC and 4 valves per cylinder, was revised over the years with 3 versions released.

5A-F 85 hp 90 lbft

  • AT170 Carina 1988–1990 (Japan only)
  • AE91 Corolla 1987–1989 (Japan only)
  • AT170 Corona 1987–1989 (Japan only)
  • AE91 Sprinter 1987–1989 (Japan only)

5A-FE 104 hp 97 lbft

  • AT170 Carina 1990–1992 (Japan only)
  • AT192 Carina 1992–1996 (Japan only)
  • AT212 Carina 1996–2001 (Japan only)
  • AE91 Corolla 1989–1992 (Japan only)
  • AE100 Corolla 1991–2001 (Japan only)
  • AE110 Corolla 1995–2000 (Japan only)
  • AE100 Corolla Ceres 1992–1998 (Japan only)
  • AT170 Corona 1989–1992 (Japan only)
  • AL50 Soluna 1996–2003 (Asia)
  • AE91 Sprinter 1989–1992 (Japan only)
  • AE100 Sprinter 1991–1995 (Japan only)
  • AE110 Sprinter 1995–2000(Japan only)
  • AE100 Sprinter Marino 1992–1998 (Japan only)

5A-FHE 120 hp

  • AE91 Corolla 1989–1992 (Japan only)
  • AE91 Sprinter 1989–1992 (Japan only)
  • AE91 Toyota G Touring 1994–1999 (Japan only)
  • AE100 Toyota G Touring 1994–1999 (Japan only)

Tuning the Toyota 5A and best 5A performance parts.

Best 5A mods

Just because particular parts are appear in lots of 5A projects it doesn't mean it is good, instead we'll best parts that will give your 5A the best value for money to power increase.

Significant gains on the 5A can be made from cam upgrades. Altering the cam profile alters the intake and exhaust durations on the engine and can dramatically change the bhp and power output.

Fast road camshafts tend to push up the torque through the rev range, you may sacrifice a little low down bhp but high end rpm power will be higher.

Competition camshafts, push up the high end rpm power band but as a result the car will not idle smoothly and low end power nearly always suffers.

A Competition camshaft is not great on the daily commute.

You should ideally match your power band to your cars usage so for a typical daily driver stick with a mild fast road 5A camshaft

Some 5A engines respond better to extreme camshaft durations than others.

The engine timing and injectors and fuel pump also have an effect on the bhp gains you'll hit.

Longer valve durations can alter the bhp 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.

Stage 1 mods: Remaps/piggy back ECU, Drilled & smoothed airbox, Panel air filters, Intake headers, Fast road camshaft, Sports exhaust manifold.

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

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

Carefully think through your options and then source your tuning parts and set yourself a power target to avoid costly mistakes.

Mapping allows a tuner to unlock the full potential of all the parts you've fitted to your 5A.

It will usually give around 30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but power output often rely on the parts you've fitted and the condition of your engine.

It is the main goal to any car tuning job to feed more air into your 5A

Intake headers carry the air during the suck phase from the air cleaner and allow it to be pulled into the engine and mixed with fuel.

The bore size, shape and flow rate of the Headers can make a big effect on to fuel engine efficiency on the 5A.

On popular production engines air intake manifolds are improved through aftermarket tuning parts, although a few manufacturers provide reasonably well designed air intake manifolds.

Adding a 5A larger valve kit, doing a bit of port matching and head flowing will also improve power, the fantastic side effect is it will allow you to get an improved power increase on other parts.

Turbo upgrades

NASP 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 5A

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

If an engine is turbo charged mods are relatively easy and you'll see that turbo engines are built using more solid components.

However you will find an engines will have power limits

Research these restrictions and install more solid crank and pistons to cope with the power.

There are many car owners spending a lots of money on turbo upgrades on the 5A only to watch the engine literally blow up just after it's been enthusiastically driven.

Big upgraded turbochargers tend to experience no power at low rpm, and small turbochargers spool up much more quickly but do not have the top end engines power gains.

Thankfully the range of turbos is always increasing and we commonly find variable vane turbos, allowing the vane angle is altered according to speed to lower lag and increase top end performance.

Twin scroll turbos divert the exhaust flow into two channels and push these at differently profiled vanes in the turbo charger. They also boost the scavenging effect of the engine.

It is not unusual that there is a restriction in the air flow sensor AFM/MAP on the 5A when considerably more air is being drawn into the engine.

Going up you'll find 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor limited performance at a much lower level.

Adding a supercharger or additional turbo will make large bhp gains, although harder to configure. We have this guide to twinchargers if you want to read more.


When you improve the bhp you will need to increase to the fuel delivery.

More bhp needs more fuel. We strongly recommend you to be generous with your flow rate on the injectors.

The accepted safe increase is to add 20% to the flow rate when buying an injector, this accounts for injector deterioration and gives you some spare capacity should the engine need 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 NASP engines

  • 58 PSI 285cc/min 200hp
  • 58 PSI 426cc/min 300hp


You should look to boost your exhaust if the current exhaust is actually creating a flow problem.

On most factory exhausts you should find that the exhaust 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.

Sports exhausts equal out the flow of air through the engine.

But if your exhaust is too big, ie: it's over 2.5 inches bore, you will lose a great deal of the flow rate and end up sapping power and torque.

Typically exhaust restrictions are in the filters installed, so adding a better flowing high performance alternative will help avoid this restriction.

Weak spots, Issues & problem areas on the 5A

The 5A engines are generally reliable and solid as long as they are regularly serviced and maintained.

Regular oil changes are vital on the 5A, especially when tuned and will help extend the life and reliability of the engine.

For more information on Tuning your 5A engine please join us in our friendly forum where you can discuss tuning options in more detail with our 5A owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

Please help us improve these tips by sending us your feedback in the comments box below.

We love to hear what our visitors have got up to and which parts work best for them on each model of car. Comments are used to improve the accuracy of these 5A articles which are continually updated.

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