Modding upgrading and tuning the BMW N52 engine!

All you need to know about "N52 Modifications"

N52 Modifications Guide

How to modify and upgrade the BMW N52

"Comprehensive guide to tuning the BMW N52 engine!"

Forums like the one at TorqueCars often are seeing threads asking how to improve the N52 from people inquiring about getting more power from the N52 and wanting to know what are the greatest N52 power upgrades. So let us look into BMW N52 parts and outline the best modifications on this great engine and point out some potential pitfalls along the way.

The BMW N52 make awesome project engines and with the right uprated mods like remaps, turbo improvements and camshafts you will substantially maximise your driving experience.

This pages aim is review N52 tuning and summarise the greatest mods that work.

The greatest N52 parts on an engine are as we have found the ones that give the best power gain for your hard earned cash.

We won't be swayed by popular N52 parts, they need to be cost effective.

N52 induction kits

Improving air intake on the N52

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 N52. We'll pick up on fuelling later in this article but for now we shall look at air supply.

So Pulling more air into the N52 engine is vital to any engine modification project.

It is not unusual that there's a limitation in the air flow sensor MAP/MAF/AFM on the N52 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 bhp at a much lower level.

Intake manifolds transmit the air from the air filter and allow it to be sucked into the engine and mixed with fuel.

The shape and flow rate of the Plenum can make a large change to fuel engine efficiency on the N52.

Many mass produced engine intake are in dire need of a performance upgrade, although some OEM provide well optimised intake.

Increasing the N52 valve size, doing a bit of port matching and head flowing will also boost bhp and torque, and significantly will give you a greater bhp and torque increase on other modifications.

N52 performance cam tips.

Some N52 engines respond better to extreme cam durations so set your engine up on a rolling road.

The ECU mapping and injectors and fuel pump also have a large bearing 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.

Significant air intake, and exhaust improvements on the N52 can be made from camshaft upgrades. Changing the camshaft profile alters the intake and exhaust durations on the engine and can dramatically change the bhp and power output.

NB: Fast road camshafts commonly boost the performance throughout the rev range, you could sacrifice a little bottom end bhp but the higher rpm power will be lifted.

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

In a car driven daily you need to match your bhp range to your usage of the car.

I'd never have ever thought a N52 Motorsport and race camshaft is a pleasure to live with when in heavy traffic.

Stage 1, 2 and 3 mods for the N52

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 N52 parts:

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

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

Stage 2 N52 parts:

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

Stage 3 N52 parts:

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

The N52 power trains respond well to mods and we see that there are increasing numbers of mods and performance parts around.

ECU mapping will help to establish the full potential of all the upgrades you've done to your N52.

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 depend much on the upgrades you've done and the condition of your engine.

Turbo modifications on the N52

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 N52.

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 has forced induction parts are going to net you a larger power gain and we find turbo engines will have stronger components.

There are reliable 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 cope with the power.

We've seen car owners spending a fortune on turbo charger upgrades on the N52 only to suffer the indignity of watching the car literally blow up just after it's finished.

Big capacity turbo chargers often experience no power at low rpm, and low capacity turbo chargers spool up quickly but won't have the top end engines power gains.

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

Twin scroll turbos divert the exhaust gases into a couple of channels and direct these at differently angled vanes in the turbocharger. 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 harder to install. We have this guide to twinchargers if you want to read more.

Tips about fuel supply on the N52

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

More power needs more fuel. We would recommend you to be generous with your injectors flow rate.

As a rule of thumb add 15% when buying an injector, helps cope with injector deterioration and affords a bit of 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 N52 performance exhaust upgrades

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

On most factory exhausts you'll see the flow rate is still 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 equal out the flow of air through the engine.

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

Typically exhaust restrictions are in the emissions filters installed, so adding a higher 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 N52

Like most engines an N52, 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 N52, failure to do this will exacerbate engine wear, on a tuned N52 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 N52 why not pop over to the forums at TorqueCars where you can chat about N52 tuning options and read about others projects who may be planning to do similar modifications on their N52.

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