Tuning the Honda R series

"Comprehensive guide to tuning the Honda R series engine!"

Now we will consider R series tuning and point out the best modifications. Honda R series offer good returns when tuned and with a few sensible uprated enhancements like remaps, turbo improvements and camshafts you will definitely enhance your driving pleasure.

Just because particular tuning parts are popular with R series owners it doesn't mean its worth having, so we'll focus tuning parts that will give your R series the best value for money to power increase.

The camshaft profile plays a big part in the engines power output so camshaft upgrades make quite a large difference. The intake and exhaust durations will alter depending on the chosen camshaft profile, so large engines power gains are on offer for camshaft upgrades.

NB: Fast road camshafts commonly push up the power across the rpm band, you could drop a little low end power but the higher rpm power will be lifted.

Competition camshafts, push up the higher rpm power band but as a result the car will not idle smoothly and low end power nearly always suffers.

A Motorsport and race cam is not great driving around busy urban areas.

You should ideally optimize your bhp range to your typical driving style so for a daily driver stick with a shorter duration R series cam

Each engine responds better to less aggressive camshaft durations check your engine on a rolling road.

The engine timing and fuel pump and injectors also have an effect on the bhp gains you'll achieve.

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.

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

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

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

Review your options and then acquire your parts and set yourself a power target to void expensive mistakes.

Remaps will help fully realize the full potential of all the parts you've fitted to your R series.

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 will vary depending on the parts you've done and the condition of your engine.

It is the aim to any engine tuning project to pull air into each cylinder

Intake headers flow the air during the suck phase from the intake filter and allow it to be pulled into the engine cylinders with fuel for the squish phase.

Design and flow characteristics of the Intake can make a substantial effect on to fuel engine efficiency on the R series.

It's not uncommon that intake headers are in dire need of a performance upgrade, although some OEM provide reasonably good intake headers.

Larger R series valves, carrying out R series port enlargement and head flowing will also raise torque, the fantastic side effect is it will make space for increasing the torque increase on other tuning mods.

Turbo upgrades

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 R 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 impressive power gains.

If the engine has forced induction tuning mods are going to make more power and turbocharged engines are built with stronger components.

However engines will need better parts at higher power limits

Discover these limits and upgrade to higher quality crank and pistons to survive the power.

There are many people spending a lots of money on turbocharger upgrades on the R series only to suffer the humiliation of seeing the engine block go up in smoke soon after it's used in anger.

Larger upgraded turbo chargers tend to experience no power at low rpm, and small turbo chargers spool up more quickly but do not have the peak end engines power gains.

Thanks to new tech the world of turbos is always moving on and we now see variable vane turbos, where the vane angle is altered according to speed to lower lag and increase top end torque.

Twin scroll turbos divert the exhaust flow into a couple of channels and push these at differently angled vanes in the turbo. They also increase the scavenging effect of the engine.

You'll commonly see there is a limit in the air flow sensor MAF/MAP on the R series when a lot more air is being sucked into the engine.

We see 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 more challenging to install. We have this article on twincharging if you want to read more.

Fuelling upgrades and mods

When you boost the bhp you will need to increase to the fuel system.

More bhp needs more fuel. We strongly recommend you to over specify your injectors flow rate.

The accepted safe increase is to add 20% to the flow rate when buying an injector, helps cope with 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.

Exhaust upgrades and mods

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

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 generally help improve air flow through the engine but do not go too wide or you could will reduce the flow rate. Stick to 1.5 to 2.5 inches as a rule of thumb.

Typically exhaust restrictions are traced to the filters installed, so adding a higher flowing performance alternative will help avoid this restriction.

Weak spots, Issues & common problem areas on the R series

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

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

For more information 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.

We need your help improving this article, so please send us your feedback in the comments box below and pass on any tips, points or facts we have wrong or have not covered.

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

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