Daihatsu Terios Tuning

"All you need to know about tuning the Daihatsu Terios engine!"

We get asked for some tips on improving the Terios and which tuning modifications we rate as the best, so this guide has been assembled goes over what we feel are the primary areas and methods of modifying and tuning on the Terios engine.

The Daihatsu Terios are awesome to work on and with carefully picked motorsport modifications like remaps, turbo kits and camshafts you will greatly maximize your driving opportunities.

Our aim here is to detail the best approach to Terios tuning and summarise the greatest modifications.

History of the Terios Engine

First generation (J100/F500; 1997)

Petrol:
658 cc EF-DEM/DET turbo I3 (Terios Kid/Lucia)
1.3 L HC-EJ I4
1.3 L K3-VE I4
1.3 L K3-VET turbo I4 (Terios/Cami)
1.5 L HE-E I4 (Taruna)
1.6 L HD-C/E I4 (Taruna)

Second generation (J200/F700; 2006)

Petrol:
1.3 L K3-VE I4
1.5 L 3SZ-VE I4

Third generation (F800/F850; 2017)

Petrol:
1.5 L 2NR-VE I4

Tuning the Daihatsu Terios and best Terios performance parts.

Best Terios upgrades

Just because particular tuning mods are appear in lots of Terios projects it doesn't mean its worth having, so we'll focus on the optimum tuning mods that will give your Terios the best value for money to power increase.

Please watch our video which covers the 5 principles of tuning your Terios. Be sure to keep up with our latest YouTube content and subscribe.

Best mods for your Terios

1. Tunes - engine tuning/remapping provides the biggest gains in terms of cost, aftermarket ECUs, and piggyback ECUs are all alternatives.
2. Fast road cams are are often the best upgrade for an engine, but they must be installed by someone who knows what they are doing and they are not always easy to source but you might find a local firm to regrind a stock camshaft.
3. Intake Upgrades and Sports Exhausts - Please 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. Forced induction upgrades - A New Turbo is the most efficient approach to increase air supply, allowing you to burn more fuel and make more power. Although one of the most costly upgrades it offers big gains.
5. Flowing and porting the engine head - for larger gains, you will get better flow and make a more efficient engine if you do this to support your other mods.

Terios Tuning Stages

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

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

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

Terios Camshaft Upgrades

Sporty camshaft profiles raise the higher RPM power which makes it a best mod for NASP and turbo petrol engines, but not so much on diesels. You will usually get a top end power gains through performance camshafts on most engines.

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

Fast road cams normally boost the bhp and torque through the rev band, you could sacrifice a little low end bhp but the higher rpm power will be higher.

Motorsport cams, boost the higher rpm power band but as a result the car will not idle smoothly and low end power nearly always suffers.

A Motorsport cam is not great in heavy traffic.

You should ideally match your bhp range to your typical driving style so for a typical daily driver stick with a fast road Terios cam

Some Terios engines respond differently primarily due to the airflow when cams are fitted depending on the cam being more or less aggressive cam durations and cam profile as unique due to manufacturing tolerances and quality variations so check your engine on a rolling road.

The map and fuel delivery and fuel pump also have an effect on the power gains you'll make.

A longer valve duration can amend the power band, and on most engines there are some advantages to extending the intake or exhaust durations and valve lift.

ECU Mapping Improvements for the Terios

Remaps should help to fully realize the full potential of all the modifications you've installed on your Terios.

(Sometimes engine tuning/remapping the ECU is not an option, so an aftermarket ECU is the route to take, and most of these exceed the specs and performance of your factory ECU's but check it has knock protection and that you get it installed right.) It will usually give around 30% more power on turbocharged vehicles and you can expect to see around 15% on NA (naturally aspirated) engines, but figures achieved usually depend much on the modifications you've applied and the condition of your engine.

Air Flow improvements on the Terios

Getting air into each cylinder is vital to any engine upgrade task.

The intake manifolds take the air from the air cleaner and allow it to be drawn into the engine cylinders.

Shape and flow characteristics of the Intake manifolds can make a large effect on to fuel atomisation on the Terios.

Commonly we find the intake manifold are begging for an upgrade, although some OEM provide fairly well optimized intake manifold.

Increasing valve sizes on Terios, doing some port work and head flowing will also boost bhp, the fantastic side effect is it will permit a greater bhp increase on other parts.

Terios 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 Terios

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.

When your car has forced induction parts are going to net you a larger power gain and most turbo engines use uprated components.

There are tuning limits for every engine, with some being over specified and some only just able to handle stock power. We recommend you find these restrictions and install better quality components to survive the power.

It's not unheard of drivers spending lots of money on turbocharger upgrades on the Terios only to watch the car go up in smoke on its first outing after it's been finished.

Big capacity turbo units commonly experience a bottom end lag, and low capacity turbo units spool up really quickly but don't have the top end bhp gains.

In recent times the choice of turbochargers is always evolving and we are seeing variable vane turbochargers, where the vane angle 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 profiled vanes in the turbocharger. They also improve the scavenging effect of the engine.

It is common that there is a limitation in the air flow sensor MAP/MAF/AFM on the Terios when loads more air is being fed into the engine.

We note 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor limited torque at a much lower level.

Adding a supercharger or additional turbo will make large performance gains, although more challenging to get working. We have this article on twincharging if you want to read more.

Terios Fuelling Upgrades

You will need to ensure that the engine is not starved of fuel so will need to ramp up the fuelling when you start exceeding 20% of a bhp and torque increase. Boosting the fuel pressure can improve the acceleration responsiveness.We would recommend you to be generous with your injectors flow rate.

The rule of thumb is to add 20% to the flow rate when fitting an injector, which takes into account injector deterioration and provides 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.

Terios Performance Exhausts

You may need to upgrade your exhaust if your current exhaust is actually causing a restriction.

On most factory exhausts you'll see the exhaust flow rate is still fine 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 increase the flow of gases through the engine.

But if your exhaust is too large, ie: over 2.5 inches bore, you will lose a lot of your flow rate and end up losing power and torque.

For road going cars mods such as a sports catalyst pretty much remove 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. And will flow much better due to it's higher internal surface area and design. The alternative test pipe mod or catalyst removal should be considered an off road only mod, as removing a catalyst is illegal in most territories and regions for road registered cars (and in some you can't even replace a working catalyst).

Weak spots, Issues & problem areas on the Terios

The Terios engines are generally reliable and solid as long as they are regularly serviced.

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 intake cleaning guide Avoid short journeys and use a good quality fuel.

Service time oil changes are essential on the Terios, especially when tuned and will help prolong the life of the engine.

If you want to learn more, or just get feedback on Tuning your Terios engine please join us in our friendly forum where you can discuss Terios tuning options in more detail with our Terios owners. It would also be worth reading our unbiased Daihatsu tuning articles to get insights into each modification and how effective they will be.

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

We love to hear what our readers have got up to and which upgrades work best for them on each model of car. We use your comments and feedback to improve the accuracy of these Terios tuning guides which get regular updates and revisions.

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This article is flagged for an update, so please pass on specific tips below that I can include. All articles, and content was written by me, Waynne Smith TorqueCars founder. Some outlines are just too general so I appreciate your feedback and suggestions. This entry was filed under Daihatsu. You can leave a response below or join our forum to discuss this article and car modification in detail with our members.

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