Tuning the BMW S63

"Comprehensive guide to tuning the BMW S63 engine!"

We are regularly getting emails requesting information on the ultimate S63 modifications. So let us look into BMW S63 modifications and outline the best mods that work on this great engine and point out some potential pitfalls along the way.

The BMW S63 have loads of potential and with the optimum sports parts like ECU maps, turbo upgrades and camshafts you will noticeably maximise your driving opportunities.

Our aim here is to examine the options for your S63 tuning and show the greatest modifications.Please watch our introduction to car tuning Video tutorial. Be sure to subscribe and support our new channel.

When talking about the ultimate parts for your S63 engine, we are going to concentrate on the tuning parts that give the best value for money.

Significant gains on the S63 can be made from camshaft upgrades. Altering 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 normally raise the torque throughout the rpm band, you may sacrifice a little bottom end torque but top end will be higher.

Motorsport and race 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 car used daily must carefully try to match your engines power to your typical driving style.

I'd be gobsmaked if you have found a S63 Race camshaft is a pleasure to live with when driving in heavy traffic.

Different S63 engines respond better to less aggressive camshaft durations so set your engine up on a rolling road.

The engine timing and fuel pump and injectors also will make differences on the power gains you'll hit.

Extending exhaust or intake durations can alter the power 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.

S63 Best Tuning Mods & Upgrades

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Guide to the best tuning mods & Upgrades

  1. ECU Map Tuning & Remaps

    Some cars may require a piggyback ECU's or aftermarket ECU's to change the OEM map, but remapping is the most vital step of your tuning project to fully maximise your mods. Expect 10-20% on NASP engines and 30-40% on turbocharged units.

  2. Strengthen Your Engine

    Tuned cars will show up weaknesses, typically in the turbochargers, clutch and internal engine components. Whilst most engines can cope with mild tuning mods, TorqueCars recommend that you upgrade the internal components before these weak spots manifest themselves.

  3. Mods that Remove a Restriction

    A restricted intake or exhaust will have an impact on your performance, so use a better flowing air filter/induction kit and better flowing exhaust (sports cats where legal are a good option) whenever your tuning creates a flow restriction. Turbo engines also benefit from intercooler upgrades as these resist heat soak for longer periods of time.

  4. Mods that Improve Fuelling

    Every tuning project will aim to increase the air supply, but fuel supply is just as vital and will need to match the air the engine can utilise,  a fuel pump and injector upgrade are usual mods, but also in many cases the fuel regulator will need improvement.

  5. Mods to Provide better Airflow

    Increasing the air supply is just as essential as improving fuelling, we suggest you look at head mods (flowing and porting, 5 angle valve jobs), fit bigger valves, fast road cams and forced induction upgrades (adding a better flowing turbo) to improve air intake.

Tuning Stages

Stage 1 S63 modifications: Remaps/piggy back ECU, Fast road camshaft, Sports exhaust manifold, Intake headers, Drilled & smoothed airbox, Panel air filters.

Stage 2 S63 modifications: Sports catalyst & performance exhaust, Ported and polished head, high flow fuel injectors, Fast road cam, fuel pump upgrades, induction kit.

Stage 3 S63 modifications: Crank and Piston upgrades to alter compression, Twin charging conversions, Adding or Upgrading forced induction (turbo/supercharger), Engine balancing & blueprinting, Competition cam, Internal engine upgrades (head flowing porting/bigger valves).

The S63 engines respond well to mods and thanks to their popularity there is an increase of parts and performance parts around.

A remap helps to establish the full potential of all the mods you've done to your S63.

It will usually give around 30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but your results often differs on the mods you've carried out and the condition of your engine.

Getting air and fuel into the S63 engine is the aim to any engine modification project.

Intake headers flow the air during the suck phase from the filter and allow it to be sucked into the engine cylinders.

The bore size, shape and flow characteristics of the Headers can make a noticeable improvement to fuel mixing and power on the S63.

I usually find headers are needing aftermarket parts, although a few makers provide reasonably good headers.

Larger S63 valves, doing a bit of 3 or 5 angle valve jobs and porting and head flowing will also raise torque, and as an added benefit will allow you to get raising the torque increase on other mods.

Turbo upgrades for the S63

NASP engines need quite a lot of work when you add a turbo, so we have a separate guide to help you take into account the pros and cons of going this route on your S63

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

When a car is fitted with a turbocharger upgrades are simpler to install and turbo engines are made using strengthened components.

There are tuning limits for every engine, with some being incredibly solid and some only just able to handle stock power

Research these limits and upgrade to higher quality crank and pistons to handle the power.

It's not unheard of people spending a lots of money on turbocharger upgrades on the S63 only to have the engine literally blow up soon after it's been completed.

Bigger turbo chargers will usually experience low end lag, and smaller turbo chargers spool up really quickly but won't have the top end torque gains.

We are pleased that the choice of turbo units is always improving and we are seeing variable vane turbo units, permitting the vane profile is altered according to speed to lower lag and increase top end bhp and torque.

Twin scroll turbo units divert the exhaust gases into two channels and direct these at differently designed vanes in the turbocharger. They also improve the scavenging effect of the engine.

It is common that there is a limit in the air flow sensor AFM/MAP on the S63 when loads more air is being sucked into the engine.

We note 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor limited performance at a much lower level.

Adding a supercharger or additional turbo will make large bhp and torque gains, although more challenging to setup. We have this article on twincharging if you want to read more.

Uprating S63 fuel injectors

When you raise the power you will need to increase to the fuelling.

More power needs more fuel. We would recommend you to over specify your injectors flow rate.

The rule of thumb is to add 20% to the flow rate when buying an injector, this takes into account injector deterioration and affords a little spare capacity should the engine need more fuel.

We think this one is common sense, but you'll need to match your fuel injector to the type of fuel your car uses as well.

Best S63 performance exhausts

Only look to improve your exhaust if the existing exhaust is actually creating a restriction.

On most factory exhausts you'll see your flow rate is still fine even on modest power gains, but when you start pushing up the power levels you will need to get a better flowing exhaust.

Sports exhausts equal out the flow of air through the engine.

But if the exhaust is too large, ie: over 2.5 inches bore, you will lose much of the flow rate and end up losing power and torque.

Typically exhaust restrictions are in the catalyst and filters installed, so adding a freer flowing high performance alternative will help avoid this restriction.

Problems and issues to look out for on the S63

The S63 engines, if regularly serviced and maintained, are generally very reliable and have few issues.

Regular oil changes are vital on the S63, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your S63 engine please join us in our friendly forum where you can discuss tuning options in more detail with our S63 owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

We need your help to complete and improve this page, so do give us your feedback in the comments box below.

We really like hearing from our readers, and hearing about which upgrades were the most effective for them, it helps us improve our recommendations and articles to reflect current trends in modifications and ensures that our S63 guides and tips are kept up to date.

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