Tuning guide "N57 Modifications"

How to modify and upgrade the BMW N57

"Comprehensive guide to tuning and performance parts on the BMW N57 engine!"

Our friends at TorqueCars often are seeing threads requesting information on how to improve the N57 from people inquiring about getting more power from the N57 and wanting to know what are the things tuners recommend when it comes to N57 power upgrades. So let us look into BMW N57 mods and outline the best modifications on this great engine and point out some problems along the way.

The BMW N57 are good project engines and with the ultimate performance enhancements like a remap, turbo improvements and camshafts you will certainly enhance your driving pleasure.

Let us examine N57 tuning and point out the optimum mods that work.

The top N57 parts on an engine are typically the ones that give the best power gain for your hard earned cash.

We won't be swayed by popular N57 parts, they need to be cost effective.

Improving air intake on the N57

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 too little air it runs rich sapping power which risks damage to the N57. We'll pick up on fuelling later in this article but for now we shall look at air supply.

So the aim to any tuning task to pull more air and fuel into each cylinder but this has a knock on effect with the air flow sensor.

It is common that there is a restriction in the air flow sensor (AFM/MAF/MAP) on the N57 when loads more air is being pulled 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 was restricting performance at a much lower level.

The intake plenum take the on the suck phase from the air cleaner and allow it to be pulled into the engine cylinders.

Design and flow characteristics of the air Intake manifold can make a big change to fuel atomisation on the N57.

I usually find plenum chambers are begging for motorsport parts, although some makers provide well optimised plenum chambers.

Larger N57 valves, getting port work and head flowing will also raise bhp and torque, & more importantly will give you a better bhp and torque increase on other modifications.

N57 performance cam tips.

Each engine responds better to different cam durations check your engine on a rolling road.

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

Longer 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.

Altering your N57 cam will make a dramatic difference to the engine torque. Choosing a higher performance cam profile raises the torque accordingly.

NB: Fast road camshafts tend to boost the performance across the rpm band, you might lose a little low down bhp but high end rpm power will be higher.

Motorsport and race camshafts, boost 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 will just annoy you whilst in heavy traffic.

You should ideally match your engines power to your driving style so for a car used daily stick with a mild fast road N57 camshaft

Stage 1, 2 and 3 mods for the N57

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 N57 parts:

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

Stage 2 N57 parts:

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

Stage 3 N57 parts:

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

ECU mapping helps fully realize the full potential of all the upgrades you've done to your N57.

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 outcome usually rely on the upgrades you've fitted and the condition of your engine.

Turbo modifications on the N57

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 N57.

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 your car has a turbocharger upgrades are going to net you a larger power gain and we find turbo charged engines use harder and stronger components.

There are tuning limits for every engine, with some being very over engineered and some only able to handle stock power

Research these restrictions and install better quality components to handle the power.

There are many tuners spending a fortune on turbocharger upgrades on the N57 only to experience the whole thing explode on it's first outing after it's used on the roads.

Bigger upgraded turbos often experience a bottom end lag, and low capacity turbos spool up more quickly but don't have the peak end engines power gains.

Thanks to new tech the selection of turbos is always increasing and we now see variable vane turbos, allowing the vane profile is altered according to speed to lower lag and increase top end power.

Twin scroll turbos divert the exhaust flow into a couple of channels and push 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 performance gains, although more complex to setup. We have this article covering twinchargers if you want to read more.

Tips about fuel supply on the N57

When you improve the bhp you will need to look at to the fuel system.

More bhp needs more fuel. Experienced mechanics will tell you to be generous with your injector capacity.

The accepted safe increase is to add another 15% when fitting an injector, this takes into account injector deterioration and provides some 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 N57 performance exhaust upgrades

Only look to replace your exhaust system with an upgraded one is if your exhaust is actually creating a restriction.

On most factory exhausts you'll find 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.

Don't go with the widest exhaust you can buy this will reduce the exhaust flow rate - the best exhausts 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.

The usual suspects causing problems in your exhaust flow rate are traced to the filters installed, so adding a better flowing race 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 N57

Like most engines an N57, 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 N57, failure to do this will exacerbate engine wear, on a tuned N57 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 N57 why not pop over to the forums at TorqueCars where you can chat about N57 tuning options and read about others projects who may be planning to do similar modifications on their N57.

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