Modding uprating the BMW BMW S65 engine!

All you need to know about "BMW S65 Modifications"

How to modify and upgrade the BMW BMW S65

"Comprehensive guide to tuning the BMW BMW S65 engine!"

Sites like TorqueCars often are getting messages about how to improve the BMW S65 from people wanting to know what are the optimum BMW S65 mods that work. So let us look into BMW BMW S65 tuning mods and outline the best mods that work on this great engine and point out some problems along the way.

The BMW BMW S65 have loads of potential and with the optimum motorsport modifications like remapping, turbo kits and camshafts you will certainly maximise your driving pleasure.

This pages aim is review and look at BMW S65 tuning and report on the best modifications for your car.

The ultimate BMW S65 tuning parts on an engine are sensibly the ones that give the biggest return for your money.

We won't be swayed by popular BMW S65 tuning parts, they need to be cost effective.

BMW S65 induction kits

Improving air intake on the BMW S65

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

So Forcing fuel and air into the BMW S65 engine is the primary aim to any engine modification task.

It is not unusual that there is a limit in the air flow sensor (AFM/MAF/MAP) on the BMW S65 when a lot more air is being pulled into the engine.

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

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

The bore size, shape and flow characteristics of the Intake can make a big difference to to fuel delivery on the BMW S65.

Most intake manifold are in dire need of aftermarket parts, although a few OEM provide well optimised intake manifold.

Larger BMW S65 valves, getting 3 or 5 angle valve jobs and porting and head flowing will also lift performance, and importantly will allow you to get increasing the performance increase on other tuning mods.

BMW S65 performance cam tips.

Different BMW S65 engines respond better to extreme cam durations so set your engine up on a rolling road.

The engine timing and fuelling also will make differences 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.

Altering your BMW S65 cam will make a dramatic difference to the engine power band. Choosing a higher performance cam profile raises the power band accordingly.

NB: Fast road cams commonly raise the performance across the rpm range, you may sacrifice a little bottom end bhp but your top end will be higher.

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

For a road car you should ideally to match your torque band to your cars usage.

You will never have found a BMW S65 Race camshaft is a pleasure to live with when driving around busy urban areas.

Stage 1, 2 and 3 mods for the BMW S65

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 BMW S65 parts:

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

Stage 2 BMW S65 parts:

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

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

Stage 3 BMW S65 parts:

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

The BMW S65 power plant are fantastic to work on and thanks to their popularity there are quite a few choices of upgrades and tuning parts around.

Remaps should help to fully realize the full potential of all the modifications you've done to your BMW S65.

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 often differs on the modifications you've done and the condition of your engine.

Turbo modifications on the BMW S65

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 BMW S65.

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.

If an engine has a turbo already fitted parts are going to net you a larger power gain and you will discover turbocharged engines are made with harder and stronger components.

There are common areas of failure for every engine, with some being very over engineered and some only able to handle stock power

See where you'll find these restrictions and fit better quality crank and pistons to survive the power.

We've seen drivers spending a loads of money on turbo charger upgrades on the BMW S65 only to suffer the humiliation of seeing the BMW S65 literally blow up when it's been completed.

Bigger turbo chargers commonly experience no power at low rpm, and low capacity turbo chargers spool up much more quickly but do not have the peak rpm torque gains.

In recent times the market of turbochargers is always evolving and we now see variable vane turbochargers, where the vane profile is altered according to speed to lower lag and increase top end torque.

Twin scroll turbochargers divert the exhaust gases into two channels and direct these at differently designed vanes in the turbocharger. They also boost 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 challenging to install. We have this guide to twinchargers if you want to read more.

Tips about fuel supply on the BMW S65

Don't overlook the need to raise the fuel delivery when you are increasing the torque - it makes the car more thirsty. We would recommend you to be generous with your flow rate on the injectors.

As a rule of thumb add another 20% when buying an injector, this allows for injector deterioration and provides you 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 BMW S65 performance exhaust upgrades

You should look to uprate your exhaust system with an upgraded one is if your current exhaust is actually causing a restriction.

On most factory exhausts you'll find the exhaust 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.

Note that with the biggest exhaust you can get 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.

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

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

Faults issues and things to look out for on the BMW S65

Like most engines an BMW S65, 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 BMW S65, failure to do this will exacerbate engine wear, on a tuned BMW S65 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 BMW S65 why not pop over to the forums at TorqueCars where you can chat about BMW S65 tuning options and read about others projects who may be planning to do similar modifications on their BMW S65.

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