Guide to tuning the D16 engine

"Thanks for reading our Honda D16 Tuning tips"

Where do you start with tuning the Honda D16 and best D16 performance parts? We often get asked for some tips on improving the D16 and which tuning modifications we rate, so we've created this article that goes over what we feel are the primary areas and methods of modifying and tuning on the D16 engine.

A good solid engine used in quite a few Civic and Integra models over the years, it makes a good project basis to work from.

With lower compression adding forced induction makes a big difference.

Just like all other engines from Honda, the D16 can be modified to get more power from it. However, the D16 doesn’t have many simple and effective bolt-on modifications and that is why sometimes the possibilities seem a bit limited. Swaps with other Honda engines are generally the way forward for a serious tuning project, our Civic engine swap guide should prove helpful.

Check out our video introduction to Honda Tuning, all you need to know about mods and upgrades on your Honda.

It is still possible to increase power by another 20% or so, relatively cheaply.

We provide a guide to D16 tuning and report on the ultimate upgrades. Honda D16's have loads of potential and with a few sensible parts you can greatly increase your driving opportunities.

NB: We have separate articles covering the best mods and upgrades for the D16 D17 & D15 and D12 D13 D14

Please watch our video which covers tuning your D series engine. Be sure to keep up with our latest YouTube content and subscribe.

Best mods for your D16

  1. Fast road Camshafts are are often the best upgrade for an engine, but they must be installed by someone who knows what they are doing and you might struggle to find one but there might be a local firm to regrind a stock cam .
  2. Remapping/Tuning the ECU - The key to unlocking power lies in the ECU and there are a few options depending on how far you are taking your D16 project.
  3. Intake and Performance Exhausts - NB: on their own these mods won't ADD POWER in most cases, but they can help lift power after other mods by removing the restriction.
  4. Flowing and porting the Head - Head work will get air flowing into the engine while removing turbulence or restrictions.
  5. Flywheel lightening - a lower mass flywheel will improve the engines ability to rev freely. But not always suitable for all D16 engines.
  6. Turbo upgrades - A New Turbo is the most significant way to raise the intake air supply, ensuring you are able to combust more fuel and make higher power. Although one of the most costly upgrades it does provide the largest gains.

D16 Tuning Stages

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

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

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

History, Power & Specs of the D16 Engine


  • 86–89 1.6 L D16A1 (Integra) DOHC
  • 86–89 1.6 L D16A3 (Integra) DOHC (Australia)
  • 88–91 1.6 L D16A6 (Civic) Si, (CRX) Si, (Civic) EX (South Africa)
  • 88–89 1.6 L D16A8 (Integra) DOHC
  • 88–89 1.6 L D16A9 (Integra) (CRX in Europe) DOHC (South Africa)


  • 98–01 D16B2 Honda Civic Aerodeck MC1 1.6i LS/ES/SR
  • 97–00 D16B2 Rover 416 Si Automatic
  • 98–00 D16B5 Honda Civic GX
  • 99- D16B6 1.6L Honda Accord (CG7/CH5, Europe)


  • 92–95 1.6 L D16Y1 (Civic) Vti SOHC (Australia)
  • 96–00 1.6 L D16Y4 (Civic) İES NON VTEC(TURKEY)
  • 96–00 1.6 L D16Y5 (Civic) HX VTEC-E
  • 97–00 1.6 L D16Y7 (Civic) DX/LX/CX
  • 96–00 1.6 L D16Y8 (Civic) EX/(Canada)Si VTEC


  • 90–92 1.6 L D16Z5 (Civic) (CRX in Europe) DOHC
  • 92–95 1.6 L D16Z6 (Civic) EX/Si, Del Sol Si VTEC
  • 98–06 1.6 L D16A (HR-V) J/J4
  • 98–06 1.6 L D16A (HR-V) JS/JS4 VTEC
  • 96–00 1.6 L D16Y8 (Civic) EX/(Canada)Si VTEC

Best D16A D16B D16Y D16Z parts

Just because a upgrades is popular with D16 owners it doesn't mean you should fit it, instead, we will highlight only those upgrades that we reckon are the best and that will give your D16 the biggest power gain return for your cash.

Here are some of the modifications that can be performed on the D16 to pull up its power:

D16 Camshaft Upgrades

D Series Camshaft Upgrades

Upgrading camshafts, such as opting for fast road cams, can significantly enhance the power at higher RPMs, making them ideal for petrol engines. Performance camshafts generally yield peak power increases across various engines, with many projects benefiting from the use of Skunk cams in the D Series.

By changing the profile of the camshaft, significant improvements in the performance of D16 engines can be obtained. Bear in mind a VTEC essentially provides a sporty cam and mild cam, so cam upgrades on the D16 are not very abundant.

It is easier to get VTEC coming in at an earlier point than to source and fit a fast road cam so this would be our proffered option for those looking to enhance the cam profile on their D series.

What does the camshaft do? This changes the intake and exhaust durations which can increase the power output.

Fast Road Cams or Competitions Cams? You have the option of going with either the fast road cams or the competition cams.

The former ones increase the power through the rpm band whereas the latter ones boost high-end rpm power. Rough idling is one of the most common issues faced as a result of aggressive cams.

Besides this, the lower-end power will also suffer. So, the choice is yours to make. For anyone looking to drive the car to work daily, the vehicle becomes extremely difficult with competition cams as at lower rpm the driving is anything but smooth.

However, if the aim is to use the car on a race track only, the sacrifice is well worth it and the driver won’t feel much agitation while driving the car concurrently getting the extra performance.

If you have VTEC it is possible to get the VTEC to cut in at lower RPM ranges effectively giving you the sportier cam profile across more of the engines power band.

For a car driven daily you need to optimize your engines power to your driving style.

Each engine responds better to more aggressive cam durations than others.

The engine timing and fuel pump and injectors also have a large bearing on the power gains you'll get.

Extending exhaust or intake 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.

The D16 engines are fantastic to work on and we're happy to report there are increasing numbers of modifications and performance parts about.

Tuning The D16 Engine.

Embarking on the adventure of remapping or engine tuning, especially for D16 engine enthusiasts, involves gathering essential tools and acquiring a foundational knowledge. It's critical to approach this with caution; diving into DIY remapping without a solid understanding can be risky.

A budget-friendly programmer like the TL866 emerges as an indispensable tool, enabling you to access and modify the ECU’s programming to extract more power.

Pairing this with complimentary software, such as HTS (Honda Tuning Suite), sets you on the path to effective remapping. Incorporating a wideband O2 sensor into your toolkit is also crucial, as it monitors the air/fuel ratio in real-time, ensuring that your engine operates at its peak performance and safety levels after adjustments.

Remap Options and Brands for D16 Engine

When it comes to ECU upgrades or remaps to enhance your D16 engine, particularly alongside modifications like the Viper Stage 3 chip, several brands are noteworthy:


The Hondata S300 is a favorite for those working with OBD1 setups, offering enhancements to the factory ECU that unlock additional power capabilities.

For those with an OBD2 system, Hondata's K-Pro or FlashPro systems are more apt choices, providing extensive tuning options such as fuel maps, ignition timing, and VTEC control. Their suitability varies with specific engine codes and ECU versions.

Viper Performance

The Viper 4x Stage 3 chip significantly boosts acceleration and is known as a Chip Sprint Throttle booster and OBD programmer module. It's an effective way to improve engine response.

AEM Infinity

The AEM Infinity ECU is a robust and flexible option, offering comprehensive tuning capabilities for a variety of vehicles and engine setups.

While it can be on the pricier side, its performance benefits are substantial.


Haltech's ECUs, including the E6k, are valued for their plug-and-play convenience and adaptability across many applications, including Honda engines.

Their straightforward interface and extensive tuning features are particularly appealing to performance enthusiasts.

Accel DFI

Accel DFI systems provide another avenue to explore, offering detailed engine management solutions that range from simple adjustments to intricate fuel and ignition management.

Feedback from those who have experience with these systems, or others from brands like Apexi or Greddy, especially on D Series engines, is invaluable. Sharing insights in comments can help spread knowledge within the community.

Moving Forward with D Series Tuning

Selecting the right ECU or remapping solution is contingent on your specific performance objectives, the existing modifications on your D series and your aspirations for the vehicle's performance. Extensive mods and upgrades typically necessitate moving beyond the OEM ECU to fully realize the engine's potential.

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 15% on NA (naturally aspirated) engines with a few other mods, but you mileage will vary depending on the upgrades you've done and the condition of your engine.

D16 Air Intake Upgrades

Air Intake Similar to modifications in all other engines, the prime objective of D16 mods is to increase power and air intake plays one of the, if not the most important role in this.

ptimizing your D16 engine's performance encompasses a comprehensive approach aimed at enhancing how effectively air and fuel are mixed and burned within the engine. An essential step in this process involves the use of an induction kit, such as the Pipercross Viper rally induction kit you've incorporated. This kit is engineered to supplant the factory air filter system with a high-performance variant, significantly increasing the volume and improving the quality of air entering the engine. The cooler, denser air provided by the induction kit contains more oxygen, crucial for achieving a more potent combustion cycle.

Upgrades to the Intake System

The function of the intake system is crucial, as it directs air from the induction kit into the engine's cylinders, where it combines with fuel for combustion. The performance characteristics of the intake manifold greatly influence this process, particularly in terms of enhancing fuel atomization. Optimized fuel atomization ensures a more complete and efficient mix of fuel with air, facilitating a cleaner, more powerful combustion.

For the D16 engine, replacing the factory intake manifold with a high-performance model can significantly improve these dynamics. While certain stock intake manifolds perform adequately, many lack the design necessary for high-level tuning, thus necessitating an upgrade to meet increased performance demands.

Valve and Port Enhancements

In conjunction with air intake improvements, upgrading to larger intake and exhaust valves enhances the engine's ability to breathe, allowing more air-fuel mixture into and exhaust gases out of the combustion chamber. Port work and head flowing further refine this process by smoothing the airflow paths, reducing resistance, and maximizing flow efficiency.

These enhancements not only boost torque but also augment the performance gains from other tuning components. This results in a synergistic increase in performance, where the whole is greater than the sum of its parts.

The Importance of ECU Remapping

An often overlooked yet critical aspect of tuning is ECU (Engine Control Unit) remapping, especially for engines like the D16 that have undergone significant modifications. Remapping the ECU allows for the optimization of the engine's fuel and ignition parameters to match the upgraded hardware, such as the induction kit, intake manifold, and valves.

ECU remapping unleashes the full potential of your engine modifications, ensuring that the enhanced airflow from the induction kit and other upgrades translates into tangible performance improvements. By fine-tuning the engine's operating parameters, you can achieve optimal power output, fuel efficiency, and responsiveness.

Using proper headers is vital as they carry the air from air filters to the engine.

Removing the restriction in the intake that was fitted to some D16 engines sold in the EU region is a good way to add power (restoring that lost power).

Carbs can be upgraded to enhance fuel delivery and if you set up a twin throat carb properly it can make really good power gains.

The fuel injected engines are more powerful, easier to tweak and offer better economy so conversion to fuel injection makes a lot of sense on the D series engines.

The overall fuel efficiency can vary drastically depending upon the type of header fixed in the car.

While some automakers manufacture effective headers, mostly the stock ones are not at par with the aftermarket components, and thus replacing headers is almost always a must while modifying your car as you will commonly find there is a restriction, especially around 20% power hikes.

The shape and flow characteristics of the Intake manifold can make a large difference to fuel engine efficiency on the D16.

I usually find intake manifolds are in dire need of a performance upgrade, although some car makers sometimes provide well optimized intake manifolds.

Big valve conversions on the D16, getting port work and head flowing will also increase torque, and significantly will allow you to get increasing the torque increase on other mods.

D16A D16B D16Y D16Z Turbo upgrades

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

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 D16

You need forced induction in the form of a turbocharger or a supercharger to feed highly compressed air to your engine. However, even if it may seem easy at first, the overall complexities only increase once you delve into a project of this sort and the D16 engine is no exception in this regard.

The major reason behind this is that a turbo is not a bolt-on modification that requires just a few easy steps. Rather, fixing it is a complicated procedure that needs to be executed perfectly.

A common issue encountered while turbocharging your D16 is knocking or the premature ignition of fuel which can have extremely bad results for the engine. For avoiding this issue, the compression ratio of the engine should be reduced and the turbo is often restricted to a lower threshold or you can use higher octane fuel and or water injection to mitigate this on the D16.

Bigger turbo chargers will usually experience no power at low rpm, and small turbo chargers spool up quickly but won't have the peak rpm power band gains.

the range of turbos is always moving on and we now see variable vane turbos, where the vane profile is altered according to speed to lower lag and increase top end bhp.

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

You'll commonly see there's a restriction in the air flow sensor AFM/MAP on these engines 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 was restricting power at a much lower level.

Adding a supercharger or additional turbo will make large bhp gains, although more difficult to get working.

D16 Fuelling Upgrades

You will need to ensure that the engine is not starved of fuel so will have to pay attention to the fuelling when you start extending past 20% of a power increase.

The early carb fed D16's can be upgraded to twin carbs for a power gain, but you'd be better off converting to fuel injection as this is easier to tune and setup for larger power gains.

The fuel pressure regulator is a good upgrade on the injected models because it improves the throttle response.

We strongly recommend you to be generous with your injector capacity.

Your D16 will need more fuel when additional performance modifications are installed. Thus, a fuelling modification becomes vital in this case. Getting an injector with a 15 to 20% enhanced capacity than the stock one is recommended in most cases.

D16 Exhaust Upgrades

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

On most factory exhausts you should find that the exhaust flow rate quite well 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 will certainly help air flow through the engine but avoid an exhaust that is too big or you might just stuff your flow rate and make things worse. So generally speaking, keep to a size of 1.5 to 2.5 inches for best results.

Typically exhaust restrictions can be located the catalyst installed, so adding a freer 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..

Weakspots and problem areas on the D16

The D16 engines are generally reliable and solid units, as long as you follow the manufacturer's 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 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.

Distributers require replacement every 20,000 miles or so, they can cause issues as they wear with tracking and misfiring.

Crankshaft pulleys are prone to failure requiring replacement, check for cracks, noise and vibrations which can be an early warning sign.

Engine idle issues are commonly down to throttle issues and cleaning usually resolves this, in some cases the Lambda (O2) sensor can be the culprit.

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 D16, 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 Honda engine please join us in our friendly forum where you can discuss D16 tuning options in more detail with our D16 owners. It would also be worth reading our unbiased Honda tuning articles to get a full grasp of the benefits and drawbacks of each modification.

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5 Responses to “D16 Tuning”

  1. Mike says:

    Hi there thank you for sharing alot for the d16.

    I’m running a d16a8 at the moment.
    And I’m struggling with sputtering. It sputters when I’m pulling off and sputters when I drive hard at 5.5k rpm. I have changed to the ignition system to brand new. Went away and came back I checked all vacuum pipes they seem good. Even the earth cables by the engine seems OK. But I haven’t changed fuel pump yet.
    But I also I saw you mentioned carbon building up in the head. Maybe that also could be the cause.

  2. TorqueCars says:

    Run some decent fuel cleaner like BG through it and see if that improves it, these faults are hard to diagnose and sometimes it’s an injector dirty o2 sensor or soiled air flow sensor that throws problems at higher rpm ranges. Try super unleaded fuel and see if that improves things, the higher octane sometimes halps with lumpy running. Carbon build up in the head is most likely to sap power through the whole rev band and will not usually cause spluttering, but it is not unheard of. Pull the fault codes from the ECU and see if any point to sensors or unusual readings.

  3. greg davis says:

    just a quyestion, i am new to the honda tuning group, i purchased someones project they lost interest in, and was wondering if the issue he had with this turbo d16y7 with a y8 head always runnung rich might have been due to the stock map sensor? has an upgraded fuel pump to feed 550 cc injectors, turbo is running just wastegage prssure and i dont know the spring but i a, guessing it limits the boost t oabout 5psi.

  4. Keith R Miller says:

    Awsome site

  5. Michael W Brewer says:

    Make sure that all the info/people are sharing Correct knowledge(Especially root out “Hearsay”), side note I think your magazine is on the right path for success, IF all the “They say” info is kept to a minimum.

    Your Local Mechanic nerd,

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