Find out about "R series Modifications"

How to modify and upgrade the Honda R series

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

Popular tuning sites like TorqueCars are always seeing threads asking how to improve the R series from people inquiring about getting more power from the R series and wanting to know what are the best tips on R series power upgrades. So let us look into Honda R series parts and outline the best upgrades on this great engine and point out some potential pitfalls along the way.

The Honda R series are fantastic to work on and with the optimum modified tuning mods like a remap, turbo kits and camshafts you will greatly increase your driving opportunities.

Here we provide a guide to R series tuning and provide tips on the ultimate modifications.

When talking about the ultimate parts for your R series engine, we are going to concentrate on the mods that give the biggest return for your cash.

Improving air intake on the R series

You need air matched to fuel for an engine to work. If there is a lack of fuel then it will run lean, if there is insufficient air it runs rich sapping power . We'll pick up on fuelling later in this article but for now we shall look at air supply.

So Pushing air and fuel into the R series engine is the primary aim to any tuning job.

It is not unusual that there's a limit in the air flow sensor (AFM/MAF/MAP) on the R series 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 was restricting power at a much lower level.

Headers flow the during the engines suck phase from the air filter and allow it to be sucked into the engine cylinders with fuel for the squish phase.

Design and flow rate of the air Intake manifold can make a big effect on to fuel atomisation and engine efficiency on the R series.

We often see air intake manifolds are needing an upgrade, although a few makers provide reasonably well designed air intake manifolds.

Big valve conversions on the R series, carrying out port work and head flowing will also lift bhp, and more importantly will raise potential for raising the bhp increase on other parts.

R series performance cam tips.

Different R series engines respond better to mild camshaft durations so view each engine as unique.

The ECU mapping and fuel pump and injectors also will say much on the torque gains you'll make.

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.

Altering your R series camshaft will make a dramatic difference to the engine bhp. Choosing a higher performance camshaft profile raises the bhp accordingly.

NB: Fast road camshafts commonly raise the bhp throughout the rev band, you may lose a little low down torque but top end will be lifted.

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

For a road car you must carefully try to optimize your engines power to your typical driving style.

I would be surprised if you have ever thought a R series Race cam is a pleasure to live with when driving around busy urban areas.

Stage 1, 2 and 3 mods for the R series

Before we break the best tuning upgrades down into stages of tune, let's list the most effective tuning upgrades for you.

1. Suspension Upgrades - always improve your cars handling
2. Brake Upgrades - Even before adding power improve those brakes
3. Intake - make sure the intake is not restricted, use filters and intake upgrades to improve this
4. Exhaust - as with 3 ensure there is not restriction in the exhaust, cats are the usual bottleneck
5. Tunes - remapping, piggyback ECU's and aftermarket ECU's can all make decent gains
6. Fuelling - when you've increased power you'll need to match this with more fuel
7. Turbo upgrades - Improving the intake with a large turbo and better flowing intercooler will be the biggest power gain you'll see (but one of the most complex).

This video guide to tuning cars is a great starting point to work from in your project.

Stage 1 R series parts:

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

Stage 2 R series parts:

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

Stage 3 R series parts:

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

Mapping helps unlock the full potential of all the parts you've done to your R series.

You will typically expect to see gains of approximately 20-30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but power output will rely on the parts you've applied and the condition of your engine.

Turbo modifications on the R series

To get a turbo working on a NASP engine there is a lot involved, from lowering compression ratio to improved fuel supply and mapping, so we have found a great guide to helpavoid the common pitfalls or end up with an unfinished project because you were not told what you were getting into by doing this on the 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 excellent power gains.

When an engine is fitted with a turbo parts are going to net you a larger power gain and we find turbocharged engines are built using uprated components.

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

Discover these restrictions and install stronger pistons, crank and engine components to utilize the power.

It's not unheard of car owners spending a lot of money on turbo charger upgrades on the R series only to see the R series literally blow up just after it's been finished.

Big upgraded turbos often experience low end lag, and small turbos spool up really quickly but won't have the peak end bhp gains.

In recent times the selection of turbochargers is always increasing and we commonly find variable vane turbochargers, permitting the vane profile is altered according to speed to lower lag and increase top end performance.

Twin scroll turbochargers divert the exhaust flow into a couple of channels and feed these at differently designed vanes in the turbo charger. They also help the scavenging effect of the engine.

Beefing up the air intake by adding a supercharger or additional turbo will help you achieve very large performance gains, although harder to configure. We have this article covering twinchargers if you want to read more.

Tips about fuel supply on the R series

Don't miss you'll need to raise the fuel system when you are increasing the performance - it makes the car more thirsty. We would recommend you to be generous with your flow rate on the injectors.

The rule of thumb is to add another 20% when specifying an injector, this accounts for injector deterioration and allows a little spare capacity should the engine need more fuel.

Don't forget that different fuel grades will usually require different settings, a high octane fuel will burn more efficiently than lower octane fuel for example. A car will trim fuel supply to keep within the ideal air fuel mix but at the extreme ends you may need to adjust your injector capacity, or the mapping or you'll get flat spots and potential lean or rich fuel issues..

Recommended R series performance exhaust upgrades

You may need to replace your exhaust system with an upgraded one is if the existing exhaust is actually creating a restriction.

On most factory exhausts you'll see your flow rate is still fine even on modest power gains, but on a serious tuning project with a big boost in power you will certainly need to get a better flowing exhaust.

Do not go with the biggest exhaust you can source this will slow the exhaust rate - the best for power gains are usually between one and a half to two and half inches. Your exhaust design, the bend angles and construction are what have more effect on flow rates than your pipe width to a certain extent. So the exhaust design is a big factor.

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

Decats (NB:catalysts reduce harmful engine emissions) is illegal in most countries and regions.

Faults issues and things to look out for on the R series

Like most engines an R series, should have few issues if it gets properly serviced and looked after.

We cannot stress enough the need for oil changes with the correct grade of oil on the R series, failure to do this will exacerbate engine wear, on a tuned R series this is more important than ever and close attention should be paid to your maintenance schedule.

If you are interested in learning more or getting impartial tuning advice for your R series why not pop over to the forums at TorqueCars where you can chat about R series tuning options and read about others projects who may be planning to do similar modifications on their R series.

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This entry was posted under Makes and Models. Tags: engine, honda
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