Honda L series Tuning

"All you need to know about performance parts and tuning the Honda L series engine!"

The Honda L series really good project engines and with the right uprated upgrades like remaps, turbo upgrades and camshafts you will certainly enhance your driving experience.

In this article we review and look at L series tuning and outline the best modifications for your car.

The most popular L series among our members is the L15B7 but all of the turbo L series engines make for fantastic project cars, L15BF, L15B7, L15B9, L15BE, L15BE and the L15BG. All engines respond well to tuning, but you'll get a lot more power for your money from the turbo units.

An engine swap between L series is an easier way to add forced induction rather than to upgrade.

Let's look at this very popular engine series from Honda and see which mods will work best on it.

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

History, Power & Specs of the Engine

L12 engine

  • L12A i-DSI
  • L12B i-VTEC

L13 engine

  • L13A i-DSI
  • L13Z i-VTEC
  • L13B i-VTEC
  • L13Z1 i-VTEC

L15 engine

  • L15A (i-VTEC / CNG)
  • L15A2 i-DSI
  • L15A1 VTEC
  • L15A7
  • L15B1
  • L15BF VTC Turbo
  • L15B7 VTC Turbo
  • L15B9 VTC Turbo
  • L15BE VTC Turbo
  • L15BE VTEC Turbo
  • L15BG VTEC Turbo
  • L15BU
  • L15C VTC Turbo
  • L15Z1 i-VTEC
  • L15Z5/2 i-VTEC
  • L15Z6 i-VTEC

L Series engines

  • LDA-MF3 (i-DSI + i-VTEC)
  • LDA-MF5 (3stage i-VTEC + IMA)
  • LDA-MF6 (i-VTEC + IMA)
  • LEA-MF6 (i-VTEC + IMA)
  • LEB (i-VTEC + Honda H1 Electric Motor Sport Hybrid i-DCD
  • LEB-MF (i-VTEC + IMA
  • LEB-MMD (i-VTEC + Sport Hybrid i-MMD
  • LFA1 (i-VTEC + Sport Hybrid i-MMD
  • LFB-H4 (i-VTEC + Sport Hybrid i-MMD
  • LFB1 (i-VTEC + Sport Hybrid i-MMD
  • LFB-13 (i-VTEC + Sport Hybrid i-MMD

The L series engine was fitted to a wide number of cars

  • 2001 1.3 L L13A (Fit/Jazz)
  • 2001 1.4  L13A (Fit/Jazz)
  • 2002 1.2 L L12A (Jazz)
  • 2002 1.5 L L15A (Fit/Fit Aria/Airwave/Mobilio)
  • 2013 1.5 L L15B DOHC (Fit)
  • 2016/2017 Honda Jade RS
  • 2016– Honda Civic turbo
  • 2017– Honda Civic Si
  • 2018– Honda HR-V
  • Honda CR-V
  • 2018– Honda Accord
  •  Honda Mobilio
  • Honda City
  • Honda BR-V
  • Honda Civic Hybrid
  • 2016 1.5 L L15B DOHC VTC Turbo (Honda Civic/Honda Accord/Honda HR-V/Honda CR-V)
  • 2012 1.5 L LEA-MF6 (Honda Civic Hybrid)

Tuning the Honda L series and best L series performance parts.

Best L series mods

When talking about the best ultimate for your L series engine, we are going to focus on the parts that give the best power gain for you money.

Significant gains on the L series 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 bump the power across the rpm band, you may sacrifice a little bottom end power but top end will improve.

Motorsport and race cams, bump 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 must carefully try to match your engines power to your driving style.

You'll never have ever thought or claimed that a L series Competition cam is a pleasure to live with when in heavy traffic because low end power will be very lumpy. Competition cams are designed for maximum power at the top end of the RPM range, a place that most daily commutes will not permit!

Each engine responds better to mild camshaft durations so view each engine as unique.

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

Longer valve durations 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.

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

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: drilled & smoothed airboxPanel air filters, Fast road camshaft, Intake manifolds, Sports exhaust header/manifold, Remaps/piggy back ECU.

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

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

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

Remaps will help to establish the full potential of all the tuning mods you've fitted to your L series.

(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 the outcome often depend much on the tuning mods you've fitted and the condition of your engine.

Forcing fuel and air into each cylinder is the whole point to any performance tuning project.

Intake manifolds take the air during the suck phase from the air cleaner and allow it to be sucked into the engine cylinders with fuel for the squish phase.

The size of bore and shape and rate of flow of the Intake manifolds can make a noticeable change to fuel delivery on the L series.

Many mass produced engine plenum chambers are ripe for motorsport parts, although a few OEM provide well optimised plenum chambers.

Larger L series performance intake, exhaust valves, and doing a bit of port matching and head flowing will also increase bhp and torque, this will make space for an improved bhp and torque increase on other modifications.

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 L series

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

If your motor is turbo charged tuning mods are more reliable and turbocharged engines are made using stronger components.

However most engines have weakspots

See where you'll find these restrictions and upgrade to more solid crank and pistons to utilize the power.

It's not unheard of people spending a a stack of money on turbocharger upgrades on the L series only to watch the engine catastrophically fail soon after it's completed.

It is common that there's a restriction in the air flow sensor MAF/MAP on these engines when loads more air is being pulled into the engine.

You'll see that 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor sapped power at a much lower level.

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


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

More torque needs more fuel. We would recommend you to over specify your injector capacity.

The accepted safe increase is to add 20% when fitting an injector, helps cope with injector deterioration and allows 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.


You should look to increase your exhaust if the current exhaust is creating a restriction in flow.

On most factory exhausts you'll find the exhaust 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 out of the engine but avoid an exhaust that is too big 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.

Usual exhaust restrictions are in the catalyst and filters 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..

Weak spots Issues & problem areas on the L series engines

The 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 , 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 engine please join us in our friendly forum where you can discuss tuning options in more detail with our 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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2 Responses to “L series Tuning”

  1. Eric says:

    Hi Waynne,
    I have a 2013 Hybrid and have always wanted a little more power. I am not a mechanic so am looking for easy upgrades that will boost power. What are you recommendations? Will it effect the Hybrid part?

  2. Deddy says:

    I have 2019 Fit with L15Z1. I want to upgrade my injector, can i take injector from another Honda Engine?

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