Tuning the Renault K9K

"Comprehensive guide to performance tuning the Renault K9K engine!"

We are always getting emails requesting information on the best K9K upgrades. So let us look into Renault K9K upgrades and outline the best modifications on this great engine and point out some problems along the way.

Therefore we look into K9K tuning and highlight the optimum upgrades. Renault K9K offer good returns when tuned and with the right uprated upgrades like remaps, turbo kits and camshafts you will increase your driving enjoyment.

When talking about the greatest parts for your K9K engine, we are going to concentrate on the modifications that give the best power gain for you money.

Altering your K9K cam will make a dramatic difference to the engine engines power. Choosing a higher performance cam profile raises the engines power accordingly.

NB: Fast road cams tend to raise the performance through the rev range, you could sacrifice a little low end torque but the top end will be lifted.

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

A Competition cam is not great on the daily commute.

You should ideally match your engines power to your usage of the car so for a road car stick with a shorter duration K9K cam

Different K9K engines respond better to less aggressive camshaft durations than others.

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

Altering 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.

K9K Tuning Stages

Stage 1 K9K modifications: Sports exhaust manifold, Drilled & smoothed airbox, Remaps/piggy back ECU, Panel air filters, Intake headers, Fast road camshaft.

Stage 2 K9K modifications: fuel pump upgrades, Sports catalyst & performance exhaust, Ported and polished head, high flow fuel injectors, induction kit, Fast road cam.

Stage 3 K9K modifications: Adding or Upgrading forced induction (turbo/supercharger), Twin charging conversions, Internal engine upgrades (head flowing porting/bigger valves), Competition cam, Engine balancing & blueprinting, Crank and Piston upgrades to alter compression.

The K9K engines respond well to upgrades and we see that there is a lot of modifications and performance parts around.

Mapping will help fully realize the full potential of all the parts you've done to your K9K.

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

It is the aim to any engine tuning project to shove more air and fuel into each cylinder

Intake headers transmit the air from the filter and allow it to be drawn into the engine and mixed with fuel.

Shape and flow rate of the Headers can make a noticeable improvement to fuel mixing and power on the K9K.

Many mass produced engine intake headers are ripe for an upgrade, although some OEM provide fairly well optimized intake headers.

Larger K9K valves, carrying out port matching and head flowing will also lift bhp, and as an added benefit will give you a better bhp increase on other tuning parts.

Turbo upgrades for the K9K

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 K9K

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 turbocharged, parts are simpler to install and most turbo charged engines are made using harder and stronger components.

There are weak spots for every engine, with some being very over engineered and some only just able to handle stock power

We recommend you find these limits and install better quality components to cope with the power.

There are many drivers spending a fortune on turbo charger upgrades on the K9K only to see the whole thing go up in smoke just after it's completed.

Big upgraded turbos will usually suffer a bottom end lag, and low capacity turbos spool up much more quickly but won't have the peak rpm power band gains.

Thanks to new tech the range of turbochargers is always developing and we now see variable vane turbochargers, where the vane profile is altered according to speed to lower lag and increase top end performance.

Twin scroll turbochargers divert the exhaust gases into two channels and feed these at differently designed vanes in the turbo. They also boost the scavenging effect of the engine.

You'll commonly see there's a limit in the air flow sensor AFM/MAP on the K9K when a lot 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 bhp at a much lower level.

Adding a supercharger or additional turbo will make large bhp gains, although more challenging to install. We have this article covering twinchargers if you want to read more.

Uprating K9K fuel injectors

You will need to ensure that the engine is not starved of fuel so should increase the fuelling when you start extending past 20% of a torque increase.We strongly recommend you to be generous with your injectors flow rate.

As a rule of thumb add 20% when fitting an injector, which takes into account injector deterioration and affords you 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.

Best K9K performance exhausts

You should look to replace your exhaust if the current exhaust is actually causing a flow problem.

On most factory exhausts you should find that your 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 air through the engine.

But if the exhaust pipe is too large, ie: over 2.5 inches bore, you will lose much of your flow rate and end up lacking power and torque.

Usual exhaust restrictions can be traced to the emissions filters installed, so adding a higher flowing race alternative will help avoid this restriction.

Problems and issues to look out for on the K9K

The K9K engines, if regularly serviced and maintained, are generally very reliable and have few issues.

Regular oil changes are vital on the K9K, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your K9K engine please join us in our friendly forum where you can discuss tuning options in more detail with our K9K owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

We need your help to complete and improve this page, so do give us your feedback in the comments box below.

We really like hearing from our readers, and hearing about which mods were the most effective for them, it helps us improve our recommendations and articles to reflect current trends in modifications and ensures that our K9K guides and tips are kept up to date.

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