Honda Civic 8th Gen Tuning

"All you need to know about performance parts and tuning the Honda Civic 8th Gen engine!"

As many of our forum members have emailed and posted questions about the Civic 8th Gen and tips on how to modify one, so we've created this guide to take you through what we feel are the main modifications that make for improvement and tuning success on this great car.

If you are on the hunt for performance modification parts for your Honda Civic 8th generation vehicle, you have come to the right spot.

The Honda Civic 8th Gen are awesome to work on and with carefully picked modified parts like remaps, turbo upgrades and camshafts you will noticeably maximise your driving opportunities.

Our aim here is to review and look at Civic 8th Gen tuning and provide tips on the optimum mods that work. So without any further ado, let’s get started.

History of the Civic 8th Gen Engine

The R18 is often replaced by the more powerful K series engines. This, however, necessitates the purchase of aftermarket headers, engine mounts, and a wiring harness for the K series engine.

There are those who prefer to use the B20 engine in place of the R18 since it offers a little more torque, but both engines provide the same overall performance. Because of this, replacing the R18 for the B20 is probably not a smart idea.

We have Civic tuning guides covering Civic 3rd Gen Mods, Civic 4th Gen Mods, Civic 5th Gen Mods, Civic 6th Gen Mods, Civic 7th Gen Mods, Civic 8th Gen Mods, Civic 9th Gen Mods, and Civic 10th Gen Mods

Tuning the Honda Civic 8th Gen and best Civic 8th Gen performance parts.

Best Civic 8th Gen upgrades

Talking about the top modifications for your Civic 8th Gen engine, we are going to focus on the tuning mods that provide the best power gain for your spend.

Tuning tips and articles

Engine tuning Transmission tuning Care care Intake & Exhaust mods Improve handling Forums

Check out our video introduction to Honda Civic Tuning, all you need to know and full guide.

Best mods for your Civic 8th Gen

  • ECU Tunes with Hondata or K tune - A Remapped Civic 8th Gen ECU provides the most power for your investment, replacement ECUs, and inline Tuning boxes are all alternatives.
  • Turbo Mods - forced induction is the most significant way to increase your intakes air supply, allowing you to burn more fuel and make power gains. Usually one of the most expensive upgrades you'll see massive gains.
  • Air Induction Mods and Exhaust - Please note that on their own these mods won't ADD POWER in most applications, but they can help lift power after other mods by losing a restriction.
  • Internal engine mods - crank, pistons, conrods & compression ratio including balancing and blueprinting
  • Civic 8th Gen Suspension - Fitting better springs and shocks radically improves your Civic 8th Gen handling Poly Bushes and Coilovers are typically fitted to achieve this
  • Braking Mods - Improve your ability to stop needs to be listed in your priority list.
  • Low mass flywheel - a lower weight flywheel will enhance the engines ability to rev freely. Not always not a great upgrade for all Civic 8th Gen engines.
  • Fast road Camshafts are generally the biggest mechanical mod upgrade, but TorqueCars recommend they be setup by someone qualified to set them up and tracking one down may be hard but you'll probably find a local firm to regrind a stock camshaft.
  • Radiator Upgrades - Keeping the engine running cool will help with power output and reliability.

Civic 8th Gen Tuning Stages

Typical stage 1 mods often include: Sports exhaust manifold, Remaps/piggy back ECU, Suspenson (mild drop), Panel air filters, Fast road camshaft, Intake manifolds.

Typical stage 2 mods often include: Suspension (Sports), Sports catalyst & performance exhaust, induction kit, high flow fuel injectors, Fast road cam, fuel pump upgrades.

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

ECU Mapping Improvements for the Civic 8th Gen

ECU flashing will help to establish the full potential of all the modifications you've fitted to your Civic 8th Gen.

ECU engine tuning/remapping is another option using which you can take your Honda Civic 8th generation vehicle’s performance to the next level.

Although several companies offer their services in this regard, Pure Tuning is noteworthy because it offers the following performance gains for the Honda Civic 2.2 I-DTEC 150 hp variant:

  • Power increase: 25 hp; Torque increase: 30 Nm.

These are impressive figures and the results are significant.

(Sometimes chip tuning the ECU is not an option, so an aftermarket ECU is the route to take, and many of these will outperform 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 will rely on the modifications you've done and the condition of your engine.

Air Flow improvements on the Civic 8th Gen

Feeding more air and fuel into each cylinder is the aim to any car tuning task.

Cold Air Intakes

Regardless of the vehicle under question, cold air intake systems should always be one of the first performance upgrades that you perform on your car.

For the Honda Civic 8th generation cars, here are a few options in this regard:

  1. Skunk2 Composite Air Intake System costing $350;
  2. Weapon R Secret Weapon Stealth Air Intake for $300;
  3. Takeda Attack Stage 2 Cold Air Intake.

Performance Air Filters

Another way of improving the flow of air to your vehicle’s engine is by using a performance air filter.

Such air filters are special in that they are less restrictive and thus the amount of air that they allow to pass through is much more than that in the case of a normal air filter.

Here are some of the options regarding performance air filters for your Honda Civic 8th generation:

  1. Takeda Pro Dry S Air Filter for $70;
  2. Injen Super Nano Air Filter for $65;
  3. Weapon R Secret Weapon Air Filter.

The intake manifolds take the air from the intake filter and allow it to be pulled into the engine cylinders with fuel for the squish phase.

The size of bore and shape and flow rate of the Intake manifold can make a large difference to to fuel atomisation on the Civic 8th Gen.

It's not uncommon that air intake manifolds are in desperate need of motorsport parts, although a few manufacturers provide reasonably well designed air intake manifolds.

Larger Civic 8th Gen valves, carrying out port matching and head flowing will also boost torque, and as an added benefit will give you a better torque increase on other mods.

Civic 8th Gen Handling/Suspension Upgrades

Adjusting the handling is often the first step in using the Civic 8th Gen.Adjusting the Civic 8th Gen's handling is often the first step in modding it.

Many people believe that a 50mm lower Civic 8th Gen suspension kit from a modified car part shop would be perfect. However, this is not the case - suspension design and setup is quite complex.

Vendors may claim that their Civic 8th Gen suspension kits are compatible with any or all model year Civic 8th Gens but to adequately support such a diverse variety of vehicles, the "one-size-fits-all" approach is obviously a mistake as engine weights and equipment trim levels all affect the cars handling characteristics.

When it comes to modifying your Civic 8th Gen, one of the most often aims and reasons is to improve its handling. However, we regularly come across the same mistakes.

Look out for a decent set of fully adjustable coilovers which allow you to lower or raise the car and this allows you to fine tune your handling.

Is there anything I should keep in mind while deciding on suspension mods for my Civic 8th Gen?

No vehicle modification can be complete without a suspension upgrade. Here are a few of the suspension parts that you can modify on your Honda Civic 8th generation vehicle:

Lowering Springs

By lowering your car, you can reduce its centre of gravity which means that the vehicle will be easier to handle on corners. Some of the options you have in this regard include:

  1. Skunk2 lowering springs having part number 519-05-1580 for $210;
  2. Eibach Pro-Kit Lowering Springs for $275;
  3. Tein H-Tech lowering springs for $240.


Coilovers provide added control to drivers so they can easily raise or lower their cars. Here are a few options in this regard:

  1. H&R Street Performance Coilover for $1250;
  2. Skunk2 Pro-S II Coilovers having part number 541-05-4750 for $820;
  3. TruHart Street Plus full coilovers for $630.

Uprated Bushes

What factors should you consider when setting up and selecting your suspension bushings if your Civic 8th Gen is also used as a daily driver?

It is possible to connect the Civic 8th Gen's suspension components to the chassis of the Civic 8th Gen using poly bushes, which are replacements for the factory mounts. The rubber ones typically lose their shape with time and need replacing anyway so why not upgrade.

By replacing new OEM rubber bushings, you may greatly improve your vehicle's performance.

It's probable that the ride may be a touch rougher because of the stronger polyurethane bushings but they'll last longer and maintain tighter handling.

They may also accelerate the decay of other suspension components due to the increased vibration and play.

A new set of poly bushings may be able to mitigate the excessive play that comes with rubber bushes.

You may struggle to find a full set of poly bushes, but most areas have the primary mounts available. Often, custom Civic 8th Gen poly bushes may be manufactured to your requirements.

How low should you go on the Civic 8th Gen?

When it comes to road vehicles, the maximum suspension drop is 30 - 37 mm, but when it comes to versions that come with lowered suspension already, the maximum suspension drop is 21 mm, according to TorqueCars.

These tolerances may be drastically diminished if the wheel size is changed. Even with 17" wheels and stock suspension, lowering the vehicle might result in a slew of complications.

Civic 8th Gen Camshaft Upgrades

Sporty camshaft profiles helps you to boost top end power and are better suited on petrol engines, than diesels. In most cases you will see top end power gains through performance camshafts on most engines.

If you have VTEC, you can get the VTEC to cut in at lower RPM ranges, essentially giving you the sportier cam profile over more of the engine's power band.

It is simpler to get VTEC to come in sooner than it is to find and install a fast road cam, therefore this is our preferred solution for people wishing to improve the cam profile on their Civic.

Significant gains on the Civic 8th Gen 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 cams usually raise the bhp across the rev band, you could sacrifice a little low down power but top end will be better.

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

In a car used daily one must carefully try to optimize your torque band to your usage of the car.

You'll never think that a Civic 8th Gen Competition cam is at all pleasant when driving in heavy traffic.This is because the lumpy idle will make the car more likely 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 Civic 8th Gen engines respond differently due to the head and flow characteristics when cams are fitted depending on the cam being more or less aggressive cam durations so view each engine and camshaft as unique due to manufacturing tolerances and quality variations so set your engine up on a rolling road.

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

Longer valve durations can alter the bhp band, and on most engines there are some advantages to extending the intake or exhaust durations and valve lift.

The Civic 8th Gen engine blocks respond well to upgrades and we see that there are increasing numbers of parts and tuning parts about.

Civic 8th Gen 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 Civic 8th Gen

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.


An intercooler is another great performance upgrade because it provides a constant source of oxygen-rich dense air to the engine.

Because oxygen is a vital part of the combustion process, by providing more of it, the performance can be significantly increased.

The GReddy Intercooler Kit for the Honda Civic 8th generation with part number 12058103 costs around $755.


A turbocharger is another effective way of quickly improving the power of your vehicle.

The BorgWarner AirWerks S400SX Super Core Turbocharger having part number 179352 costs around $1150 and works perfectly for your Honda Civic 8th generation vehicle.

The 8th Gen Civic Si FG2 FA% AirWerks T3 Turbo kit is another option but it costs a lot of money. This kit can be had for around $4800.

It includes the following parts:

  • Full-Race K-Series FG Turbo Manifold;
  • Full-Race K-Series FG 3" Downpipe;
  • Full-Race K-Series FG Vertical Flow Intercooler;
  • Full-Race K-Series FG Charge Piping;
  • Full-Race K-Series FG Kit Box.


If you want to add a supercharger to your Honda Civic 8th generation vehicle, you can choose from the following options:

  • KraftWerks Supercharger Kit for $3680;
  • CT Engineering Supercharger Kit for $3519.

It is worth noting that for using these superchargers and turbochargers, you will have to put in Octane 91 or higher fuel in the vehicle. Besides this, colder spark plugs will also be required.

However you'll find engines will need better parts at higher power limits. Discover these limits and upgrade to higher quality components to utilize the power.

We see many tuners spending a lot of money on turbocharger upgrades on the Civic 8th Gen only to watch the motor throw a rod soon after it's first rolling road session.

Large capacity turbo units will usually suffer a bottom end lag, and small turbo units spool up quickly but do not have the high rpm engines power gains.

Thanks to progress the range of turbo units is always improving and we are seeing variable vane turbo units, allowing the vane angle is altered according to speed to lower lag and increase top end performance.

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

It is not unusual that there's a limitation in the air flow sensor (AFM/MAF/MAP) on the Civic 8th Gen when loads more air is being drawn into the engine.

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

Adding a supercharger or additional turbo will make large bhp gains, although harder to install. We have this in depth look at twinchargers if you want to read more.

Civic 8th Gen Alloy wheel upgrades.

Due to the fact that alloys are lighter they improve performance and they help to cool the brake disks. Pay attention to your choice of tyres (tires) for your car, a good directional tread pattern tire can really enhance your cars handling.

Here are some of the manufacturers that offer a wide array of wheel options for Honda Civic 8th generation vehicles:

  • Enkei;
  • Gram Lights;
  • SSR;
  • BC Forged;
  • VMR;
  • MOMO;
  • Vossen.

Please note although they can look cool on the Civic 8th Gen large alloy wheels will actually decrease your performance. The larger you go the lower your acceleration will be - this to the change in your effective final drive ratio.

For this reason endeavour to keep the overall rolling diameter of the wheel the standard factory sizes. In all cases avoid going over 18 inches.

Civic 8th Gen Fuelling Upgrades

When you raise the bhp you will need to pay attention to to the fuel delivery.

More bhp needs more fuel. Fuel pressure boost valves raise the fuel pressure, can provide a better throttle response.

No matter how much money you spend on the turbochargers or air intakes, if you can't deliver enough fuel to the engine, all of these efforts will lead to no results.

Thus, you need to choose from the following options if you want to supply an adequate amount of fuel to the engine for getting enhanced performance figures.

Fuel Injectors

A fuel injector as the name gives away injects fuel to the vehicle’s engine. The stock injectors are designed to provide only a limited amount of fuel to the engine.

However, when you supply more air using the cold air intake systems, you will need to put aftermarket parts for getting the desired results.

Some of the options in this regard include:

  • Injector Dynamics ID1300x fuel injectors for $900;
  • SiriMoto EV14 Fuel Injector Kit for $300;
  • DeatschWerks Fuel Injectors for $320.

Fuel Pump

If you want to upgrade the fuel pump of your Honda Civic 8th generation vehicle, you can choose from:

  • DeatschWerks In-Tank High Flow Fuel Pump for $100;
  • AEM High Flow Fuel Pump for $125.

Don't forget to be generous with your injectors flow rate.

The accepted safe increase is to add 20% capacity when buying an injector, this accounts for injector deterioration and gives 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.

Civic 8th Gen Performance Exhausts

You may need to uprate your exhaust if the existing exhaust is actually creating a flow problem.

On most factory exhausts you'll find your flow rate is good 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 out of the engine but do not go too wide or you could restrict the flow rate. Keep the exhaust pipes to around 1.5 to 2.5 inches as a rule of thumb.

An exhaust system plays a key role in any vehicle’s performance upgrade. The exhaust not just adds to the performance by reducing backfiring of gases but can also add to the aggressive sound of the modified cars.

Here are a few exhaust upgrade options for the Honda Civic 8th generation vehicles.

  1. MagnaFlow Street Series Stainless Steel Cat-Back Exhaust System with part number 16687 for $892;
  2. aFe Power Takeda 304 Stainless Steel Axle-Back Exhaust System for $620;
  3. Skunk2 MegaPower Exhaust System for $560;
  4. APEXi N1 Evolution Exhaust System for $550.

Usual exhaust restrictions can be located in the catalyst installed, so adding a higher flowing performance aftermarket version unlocks that lost power, and without resorting to doing an illegal catalyst removal, will keep the car road legal. We should explain that performance catalysts and filters perform a similar power improvement to catless exhaust mod and have the added benefit of keeping your car street legal, as decat or catalyst removal is not a legal mod.

Weak spots, Issues & problem areas on the Civic 8th Gen

The Civic 8th Gen engines are fairly reliable as long as they are well maintained.

The 8th generation Honda Civic was plagued by concerns about engine issues. Other problems, such as coolant leakage, resulted from engine block cracks.

The 2005 Honda Civic was the first model year to have airbag issues. Even now, Honda is recalling the 8th generation Civic cars to remedy the airbag Takata inflator problem.

Carbon build up in the head, particularly around the valves which will reduce power, this is a very common problem on direct injection engines but should be looked out for on all engines. We have tips on intake cleaning guide To minimize this risk only use quality fuel and don't short journeys.

Regular oil changes are essential on the Civic 8th Gen, and more importantly so when the car is tuned and will help ensure reliability of the engine.

Civic 8th Gen Radiator Upgrades

A car’s radiator is vital for keeping it cool. Thus, if you are looking forward to replacing the radiator of your Honda Civic Si variant, you should try the Alpha Radiator from Skunk2 having part number 349-05-3000 which costs around $220.

Another option is the FG 8th generation Civic K Series Vertical flow intercooler. This part costs around $1100.

If you want to know more, or just get tips on Tuning your Civic 8th Gen engine please join us in our friendly forum where you can discuss Civic 8th Gen tuning options in more detail with our Civic 8th Gen owners. It would also be worth reading our unbiased Honda 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 appreciate people taking the time to tell us what our members have got up to and which modifications work best for them on each model of car. We use your comments and feedback to improve the accuracy of these Civic 8th Gen tuning guides which get regular updates and revisions.

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