Modding uprating the Honda B18 engine!

Discover "B18 Modifications"

How to modify and upgrade the Honda B18

"Comprehensive guide to performance tuning the Honda B18 engine!"

Sites like TorqueCars are always getting messages about how to improve the B18 from people wanting to know what are the best B18 power upgrades. So let us look into Honda B18 modifications and outline the best mods that work on this great engine and point out some potential pitfalls along the way.

Car Tuning Tips will provide a guide to B18 tuning and summarise the greatest modifications for your car. Honda B18 make awesome project engines and with the ultimate enhancements like ECU maps, turbo improvements and camshafts you will substantially increase your driving fun.

Just because particular upgrades are popular with B18 owners it doesn't mean it is good, we will focus on the greatest upgrades that will give your B18 the best value for money to power increase.

Without us subscribing to the popular myth 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'.

B18 induction kits

Improving air intake on the B18

You need air matched to fuel for an engine to work. If there is little supply of fuel then it will run lean, if there is a lack of air it runs rich resulting in lost power which risks damage to the B18. We'll pick up on fuelling later in this article but for now we shall look at air supply.

So it's important to any engine tuning project to feed fuel and air into your B18 but this has a knock on effect with the air flow sensor.

It is not unusual that there's a limit in the air flow sensor (AFM/MAF/MAP) on the B18 when considerably more air is being sucked into the engine.

When tuning you may well find you need to get an air sensor or flow meter capable of upto 4 bars to cope with quite large power gains, whereas the OEM air sensor limited power at a much lower level.

Intake headers flow the air from the air cleaner and allow it to be sucked into the engine and mixed with fuel.

The shape and rate of flow of the Intake headers can make a big difference to to fuel atomisation and engine efficiency on the B18.

Many mass produced engine intake manifold are crying out for motorsport parts, although some manufacturers provide well optimised intake manifold.

Larger B18 valves, doing some port matching and head flowing will also raise power, and significantly will afford you a better power increase on other tuning mods.

B18 performance cam tips.

Some B18 engines respond better to extreme camshaft durations so set your engine up on a rolling road.

The engine timing and injectors and fuel pump also will say much on the torque gains you'll achieve.

Altering 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.

Significant air intake, and exhaust improvements on the B18 can be made from cam upgrades. Changing the cam profile alters the intake and exhaust durations on the engine and can dramatically change the bhp and power output.

NB: Fast road cams normally boost the torque throughout the rpm band, you may lose a little low end bhp but your higher rpm power will improve.

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

On a road car you need to optimize your torque band to your typical driving style.

I'd be shocked if you find a B18 Motorsport and race camshaft is a pleasure to live with when in heavy traffic.

Stage 1, 2 and 3 mods for the B18

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 B18 parts:

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

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

Stage 2 B18 parts:

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

Stage 3 B18 parts:

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

The B18 engines respond well to upgrades and we're happy to report there is a lot of modifications and tuning parts around.

ECU mapping helps release the full potential of all the tuning parts you've done to your B18.

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 usually rely on the tuning parts you've carried out and the condition of your engine.

Turbo modifications on the B18

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 B18.

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.

When an engine has a turbocharger parts are giving better power gains and you will discover turbocharged engines are built using harder and stronger components.

There are weak spots for every engine, with some being incredibly solid and some only able to handle stock power

Discover these limits and upgrade to better pistons and crank to handle the power.

We see many guys spending a loads on turbo charger upgrades on the B18 only to experience the B18 throw a rod just after it's been enthusiastically driven.

Bigger capacity turbos often experience no power at low rpm, and small turbos spool up more quickly but do not have the high rpm bhp gains.

Thanks to progress the selection of turbos is always increasing and we are seeing 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 2 channels and direct these at differently angled vanes in the turbo charger. They also increase the scavenging effect of the engine.

Beefing up the air intake by adding a supercharger or additional turbo will help you achieve very large power 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 B18

You will need to ensure that the engine is not starved of fuel so will need to increase the fuelling when you start going beyond 20% of a bhp hike. We strongly recommend you to over specify your injectors flow rate.

The rule of thumb is to add another 15% when fitting an injector, helps cope with injector deterioration and provides 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 B18 performance exhaust upgrades

We'd only recommend you look to increase your exhaust system with an upgraded one is if your current exhaust is actually causing a flow problem.

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

Sports exhausts generally help improve air flow out of the engine but do not go too big or you could will reduce the flow rate. Stick to one and a half to two and half inches for best results.

Usual exhaust restrictions are in the filters installed, so adding a better flowing sports alternative will help avoid this restriction.

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

Faults issues and things to look out for on the B18

Like most engines an B18, 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 B18, failure to do this will exacerbate engine wear, on a tuned B18 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 B18 why not pop over to the forums at TorqueCars where you can chat about B18 tuning options and read about others projects who may be planning to do similar modifications on their B18.

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