Modifying and tuning the N62

Tuning guide "BMW N62 Tuning"

BMW N62 Tuning Guide

"Comprehensive guide to tuning and performance parts on the BMW N62 engine!"

We shall detail the best approach to N62 tuning and highlight the greatest modifications. BMW N62 make a good tuning project and with the right sports modifications like ECU maps, turbo kits and camshafts you will definitely increase your driving pleasure.

The optimum N62 tuning mods on an engine are usually the ones that give the biggest return for your cash.

We won't be swayed by popular N62 tuning mods, they need to be cost effective.

Significant gains on the N62 can be made from cam upgrades. Altering the cam profile alters the intake and exhaust durations on the engine and can dramatically change the power band and power output.

NB: Fast road cams commonly boost the power throughout the rpm band, you may sacrifice a little bottom end power but the top end will improve.

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

A Competition cam won't do well if in heavy traffic.

You should ideally optimize your bhp range to your cars usage so for a road car stick with a shorter duration N62 cam

Some N62 engines respond better to more aggressive camshaft durations so view each engine as unique.

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

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.

Our top 7 top upgrades for your motor, and we will break these into stages and discuss them in detail for you.

  1. Map Tunes - remapping, via either OBD port, or piggyback ECU's and aftermarket ECU's can all make decent gains
  2. Fuelling Pump Injectors - You'll need to match the greater air flow with more fuel to unlock the power
  3. Turbo upgrades - Improving the intake charge with a large turbo and better flowing intercooler will be the biggest power gain you'll see (but one of the most complex especially where conversions are required).
  4. Suspension Upgrades - always improve your cars handling, tuning is not just about engine mods
  5. Brake Upgrades - Even before adding power improve your cars brakes to effectively stop the car
  6. Intake - make sure the intake is not restricted, use filters and intake upgrades to improve this
  7. Exhaust - as with intakes it helps to remove a restriction in the exhaust, cats are the usual bottleneck

This video guide to tuning cars is a great starting point to work from in your project.

Stage 1 mods: Remaps/piggy back ECU, Panel air filters, Fast road camshaft, Sports exhaust manifold, Drilled & smoothed airbox, Intake headers.

Stage 2 mods: Ported and polished head, Fast road cam, induction kit, fuel pump upgrades, high flow fuel injectors, Sports catalyst & performance exhaust.

Stage 3 mods: Engine balancing & blueprinting, Internal engine upgrades (head flowing porting/bigger valves), Twin charging conversions, Adding or Upgrading forced induction (turbo/supercharger), Crank and Piston upgrades to alter compression, Competition cam.The N62 engine blocks are great to work on and we're happy to report there are quite a few choices of modifications and tuning parts about.

ECU mapping allows a tuner to unlock the full potential of all the upgrades you've done to your N62.

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 fitted and the condition of your engine.

Forcing more air into each cylinder is the whole point to any engine performance tuning job.

The intake plenum take the air during the suck phase from the filter and allow it to be sucked into the engine and mixed with fuel.

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

The shape and flow rate of the Intake headers can make a large effect on to fuel mixing and power on the N62.

Commonly we find the air intake manifolds are crying out for a performance upgrade, although a few OEM provide well optimised air intake manifolds.

Increasing the N62 valve size, carrying out 3 or 5 angle valve jobs and porting and head flowing will also lift power, this will give you increasing the power increase on other parts.

N62 Turbo upgrades

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 a separate 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 N62

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 a car is turbocharged, parts are simpler to install and we find turbocharged engines are built with more solid components.There are common areas of failure for every engine, with some being over specified and some only able to handle stock power

Discover these restrictions and install stronger pistons, crank and engine components to utilize the power.

We've seen car owners spending a lots of money on turbo charger upgrades on the N62 only to see the whole thing throw a rod soon after it's been enthusiastically driven.

Big turbos often suffer low end lag, and small turbos spool up much more quickly but do not have the peak rpm bhp gains.

In recent times the world of turbo units is always increasing and we now see variable vane turbo units, where the vane angle is altered according to speed to lower lag and increase top end performance.

Twin scroll turbo units divert the exhaust gases into a couple of channels and push these at differently profiled vanes in the turbo. They also help the scavenging effect of the engine.

It is not unusual that there is a restriction in the air flow sensor MAF/MAP on the N62 when loads more air is being pulled into the engine.

We note 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor sapped torque at a much lower level.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 feature on twinchargers if you want to read more.

N62 Fuelling upgrades and mods

Don't omit to raise the fuel system when you are increasing the bhp - it makes the car more thirsty. 

We would recommend you to be generous with your injector capacity.

As a rule of thumb add 20% to the flow rate when fitting an injector, this accounts for injector deterioration and provides a bit of 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..

N62 Exhaust upgrades and mods

You only need to to increase your exhaust if your current exhaust is actually causing a restriction in flow.

On most factory exhausts you should find that the flow rate is fine even on modest power gains, but when you start pushing up the power levels you will need to get a better flowing exhaust.Please dont run with the largest exhaust you can buy this will slow up 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.

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

N62 Issues & common problems

The N62 engines, if regularly serviced and maintained, are generally very reliable and have few issues.

Regular oil changes are vital on the N62, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your N62 engine please join us in our friendly forum where you can discuss tuning options in more detail with our N62 owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

Please help us improve these tips by sending us your feedback in the comments box below.

We really like hearing from our readers, and hearing about which modifications were the most effective for them, it helps us improve our recommendations and articles to reflect current trends in modifications and ensures that our N62 guides and tips are kept up to date.

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