Modding uprating the Nissan RB20 engine!

All you need to know about "RB20 Modifications"

RB20 Modifications Guide

How to modify and upgrade the Nissan RB20

"Comprehensive guide to tuning the Nissan RB20 engine!"

Our friends at TorqueCars are frequently getting emails asking about how to improve the RB20 from people inquiring about getting more power from the RB20 and wanting to know what are the best RB20 modifications. So let us look into Nissan RB20 upgrades and outline the best modifications on this great engine and point out some potential pitfalls along the way.

Car Tuning Tips will consider RB20 tuning and report on the premier mods that work. Nissan RB20 great bases for a tuning project and with the best tuning parts like remaps, turbo kits and camshafts you will certainly improve your driving experience.

Just because particular tuning mods are are common on RB20 it doesn't mean it is good, instead we'll focus on the optimum tuning mods that will give your RB20 the best power gain for you money.

Without us subscribing to the misaprehension of 'if it's shiny and makes more noise it must be good' you seem to get in many tuning magazines and on car forums'.

RB20 induction kits

Improving air intake on the RB20

You need air matched to fuel for an engine to work. If there is not enough fuel then it will run lean, if there is not enough air it runs rich resulting in lost power . We'll pick up on fuelling later in this article but for now we shall look at air supply.

So the fundamental goal to any car tuning job to shove more air into the RB20 engine but this has a knock on effect with the air flow sensor.

It is not unusual that there is a limit in the air flow sensor AFM/MAF on the RB20 when a lot more air is being fed into the engine.

We see 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor was restricting performance at a much lower level.

Intake flow the during the engines suck phase from the filter and allow it to be sucked into the engine and mixed with fuel.

The shape and flow rate of the Headers can make a big change to fuel atomisation on the RB20.

Most intake are improved through motorsport parts, although a few makers provide fairly well optimized intake.

Increasing the RB20 valve size, doing a bit of RB20 port enlargement and head flowing will also lift performance, and more importantly will allow you to get raising the performance increase on other modifications.

RB20 performance cam tips.

Some RB20 engines respond better to more aggressive camshaft durations so view each engine as unique.

The ecu map and fuelling also will make differences on the torque gains you'll make.

Extending exhaust or intake 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.

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 power band gains are on offer for camshaft upgrades.

NB: Fast road cams usually raise the bhp and torque through the rpm range, you could drop a little bottom end power but your top end will be better.

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 Motorsport camshaft will just annoy you whilst on the daily commute.

You should ideally optimize your power band to your cars usage so for a car driven daily stick with a shorter duration RB20 camshaft

Stage 1, 2 and 3 mods for the RB20

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 RB20 parts:

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

Tuning tips and articles Engine tuning Transmission tuning Care care Intake & exhaust mods Improve handling Forums

Stage 2 RB20 parts:

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

Stage 3 RB20 parts:

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

Carefully think through your options and then source your upgrades and set yourself a power target to avoid expensive mistakes.

Remaps should help to fully realize the full potential of all the upgrades you've done to your RB20.

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 the end result may vary depending on the upgrades you've carried out and the condition of your engine.

Turbo modifications on the RB20

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 RB20.

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.

When your car has a turbocharger parts are relatively easy and turbo engines are made with uprated components.

There are practical limits for every engine, with some being over specified and some only able to handle stock power

See where you'll find these limitations and upgrade to better quality components to handle the power.

It's not unheard of drivers spending a loads on turbocharger upgrades on the RB20 only to suffer the indignity of watching the car throw a rod on it's first outing after it's been finished.

Big turbo units tend to experience low end lag, and low capacity turbo units spool up more quickly but don't have the top end torque gains.

We are pleased that the choice of turbo chargers is always developing and we commonly find variable vane turbo chargers, where the vane angle is altered according to speed to lower lag and increase top end performance.

Twin scroll turbo chargers divert the exhaust gases into a couple of channels and push these at differently designed vanes in the turbocharger. They also improve the scavenging effect of the engine.

Beefing up the air intake by adding a supercharger or additional turbo will help you achieve very large bhp and torque gains, although more difficult to get working. We have this article covering twinchargers if you want to read more.

Tips about fuel supply on the RB20

When you lift the performance you will need to ramp up to the fuel delivery.

More performance needs more fuel. Care modifiers usually say to be generous with your injectors flow rate.

The rule of thumb is to add 20% to the flow rate when specifying an injector, this accounts for injector deterioration and provides some spare capacity should the engine require 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 RB20 performance exhaust upgrades

You should look to upgrade your exhaust system with an upgraded one is if your exhaust is actually causing a restriction in flow.

On most factory exhausts you should find that the flow rate is ok 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.

Sports exhausts can help equal out the flow of air through the engine.

But if the exhaust is too large, ie: over two and a half inches diameter, you will lose a great deal of the exhaust flow rate and end up lacking power and torque.

The usual suspects causing problems in your exhaust flow rate come around the catalysts installed, so adding a better flowing high performance 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 RB20

Like most engines an RB20, 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 RB20, failure to do this will exacerbate engine wear, on a tuned RB20 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 RB20 why not pop over to the forums at TorqueCars where you can chat about RB20 tuning options and read about others projects who may be planning to do similar modifications on their RB20.

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