Tuners tips on "S54 Modifications"

How to modify and upgrade the BMW S54

"Comprehensive guide to tuning the BMW S54 engine!"

TorqueCars are regularly getting posts asking about how to improve the S54 from people wanting to know what are the best S54 modifications. So let us look into BMW S54 upgrades and outline the best modifications on this great engine and point out some frequent tuning mistakes along the way.

Now we shall look into S54 tuning and provide tips on the best upgrades. BMW S54 offer good returns when tuned and with the right sports enhancements like ECU maps, turbo kits and camshafts you will noticeably enhance your driving experience.

When talking about the greatest parts for your S54 engine, we are going to concentrate on the parts that give the best power gain for you spend.

Improving air intake on the S54

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

So Forcing more air and fuel into each cylinder is the aim to any tuning task.

You'll commonly see there is a limit in the air flow sensor AFM/MAP on the S54 when loads more air is being fed into the engine.

You'll see that 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor was restricting bhp and torque at a much lower level.

Engine intake manifolds carry the on the suck phase from the intake filter and allow it to be sucked into the engine and mixed with fuel.

Structure and flow characteristics of the Air Intake manifolds can make a large effect on to fuel engine efficiency on the S54.

On popular production engines intake manifold are needing aftermarket tuning parts, although a few makers provide well optimised intake manifold.

Adding a S54 larger valve kit, carrying out S54 port enlargement and head flowing will also improve bhp and torque, and as an added benefit will afford you increasing the bhp and torque increase on other upgrades.

S54 performance cam tips.

Some S54 engines respond better to different camshaft durations check your engine on a rolling road.

The map and injectors and fuel pump also have a large bearing on the torque gains you'll get.

A longer valve duration 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 S54 can be made from camshaft upgrades. Changing the camshaft profile alters the intake and exhaust durations on the engine and can dramatically change the engines power and power output.

NB: Fast road cams commonly bump the bhp across the rpm range, you could drop a little bottom end bhp but your high end rpm power will be better.

Motorsport cams, bump the high end rpm power band but as a result the car will not idle smoothly and low end power nearly always suffers.

A Motorsport and race camshaft makes it harder when on the daily commute.

You should ideally optimize your bhp range to your cars usage so for a car used daily stick with a mild fast road S54 camshaft

Stage 1, 2 and 3 mods for the S54

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 S54 parts:

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

Stage 2 S54 parts:

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

Stage 3 S54 parts:

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

ECU mapping allows a tuner to to establish the full potential of all the parts you've done to your S54.

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 figures achieved usually vary depending on the parts you've fitted and the condition of your engine.

Turbo modifications on the S54

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 S54.

The more air you can get into an engine, the more fuel it can burn and uprating the induction with a turbocharger upgrade makes major power gains.

If your motor is turbocharged, tuning parts are going to net you a larger power gain and we find turbo engines will have strengthened components.

There are common areas of failure for every engine, with some being extremely strong and some only just able to handle stock power

Discover these restrictions and upgrade to more solid crank and pistons to survive the power.

We've seen drivers spending a loads of money on turbo upgrades on the S54 only to watch the engine literally blow up when it's been enthusiastically driven.

Larger capacity turbos will usually suffer low end lag, and low capacity turbos spool up really quickly but won't have the top end torque gains.

Thanks to new tech the range of turbo units is always developing and we are seeing variable vane turbo units, where the vane profile is altered according to speed to lower lag and increase top end torque.

Twin scroll turbo units divert the exhaust gases into 2 channels and feed these at differently designed vanes in the turbo charger. 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 gains, although more difficult to get working. We have this feature on twinchargers if you want to read more.

Tips about fuel supply on the S54

When you increase the torque you will need to ramp up to the fuelling.

More torque needs more fuel. Don't forget to be generous with your injector capacity.

As a rule of thumb add 20% to the flow rate 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 S54 performance exhaust upgrades

You may need to boost your exhaust system with an upgraded one is if the current exhaust is creating a flow problem.

On most factory exhausts you'll see the 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 can usually air flow through the engine but avoid an exhaust that is too large or you could will reduce the flow rate. Stick to one and a half to two and half inches for best results.

Typically exhaust restrictions can be traced to the catalyst installed, so adding a faster flowing high performance alternative will help avoid this restriction.

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

Faults issues and things to look out for on the S54

Like most engines an S54, 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 S54, failure to do this will exacerbate engine wear, on a tuned S54 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 S54 why not pop over to the forums at TorqueCars where you can chat about S54 tuning options and read about others projects who may be planning to do similar modifications on their S54.

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