BMW S85 Tuning

"All you need to know about tuning the BMW S85 engine!"

Welcome to the realm of high-performance engineering with the BMW S85 engine – a powerhouse that has left an indelible mark on the world of automotive enthusiasts.

Born in the mid-2000s, the S85 stands tall as a member of BMW's esteemed high-performance M series engines.

This was an era when eco mods and emissions were not even discussed making the S85 an important part of the last generation of project engines and is also an engine I remember fondly from my Boss's car collection.

Let's embark on a journey to uncover the history, power specifications, revisions, and distinctive features that make the S85 a captivating canvas for modification and upgrades.

Now, as we explore the landscape of modifying and upgrading the S85, we delve into a realm where precision meets passion.

From performance exhaust systems that unleash the v10 engine's symphony to precision tuning solutions that fine-tune every nuance, the S85 beckons enthusiasts to explore evolve and explore its capabilities.

This article aims to guide fellow engineering enthusiasts through the art and science of modifying the S85 engine.

Together, let's unlock the untapped potential of this engineering masterpiece, ensuring that each modification enhances the driving experience without compromising the essence that makes the S85 a true icon in the world of high-performance engines.

This pages aim is to examine the world of S85 tuning and outline the greatest upgrades. BMW S85 are good project engines and with carefully picked tuning parts like ECU maps, turbo improvements and camshafts you will dramatically improve your driving fun.

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History, Power & Specs of the Engine

The S85 is a naturally aspirated V10 and was the first and only production V10 engine BMW produced.

The S85 engine found its home in the BMW E60 M5 sedan and the E63 M6 coupe and convertible. These models were not just vehicles; they were embodiments of driving passion, blending luxury and performance in a harmonious marriage.

• S85B50
• 373 kW (500 bhp)@7,500 rpm
  520 nm (384 lbft)@6,100 rpm

Engine History: The S85 engine made its debut in 2005, powering the BMW E60 M5 and later the E63 M6. This V10 marvel was not just an engine; it was a symphony of precision engineering designed to deliver a visceral driving experience.

Unveiling a departure from BMW's typical inline-six and V8 configurations, the S85 showcased the brand's prowess in pushing the boundaries of performance.

Power Specifications: The numbers speak volumes. The S85 V10 roared with a naturally aspirated spirit, producing around 500 horsepower and an exhilarating 384 lb-ft of torque.

The redline soared to an impressive 8,250 RPM, emphasizing the engine's commitment to delivering power across a broad range.

Beyond the raw power, the S85 featured advanced technologies to raise performance over it's predecessor.

Notably, it boasted the Double VANOS system, optimizing camshaft timing for enhanced power delivery and efficiency.

This system, combined with individual throttle bodies for each cylinder, contributed to the engine's remarkable responsiveness.

Tuning the BMW S85 and best S85 performance parts.

Best S85 tuning mods

When talking about the best best for your S85 engine, we are going to concentrate on the mods that give the best power gain for you spend.

Significant gains on the S85 can be made from camshaft upgrades. Altering the camshaft profile alters the intake and exhaust durations on the engine and can dramatically change the torque and power output.

Fast road cams commonly boost the power across the rev range, you could sacrifice a little low down power but your top end will be lifted.

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

Schrick offer a decent option with a 292.280 and 296/284 profile depending on where you want the power on your S85 and how you plan to use it.

Here in the Uk camshaft specialists such as Piper and Kent can offer custom grinds on stock cams to help you attain the ideal profile and power delivery in your S85 project.

In a car used daily, really you should, ideally aim to match your torque band to your typical driving style.

I'd be surprised if you find a S85 Motorsport cam is a pleasure to live with when on the daily commute, because the lumpy idle will make the car prone to stall and smooth driving at low rpm becomes impossible. If you are developing a track car this doesn't matter as you are in the high end of your RPM range anyway and that is where you want the power to be.

Each engine responds better to mild camshaft durations so set your engine up on a rolling road.

The engine timing and fuelling also have an effect 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.

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Best mods for your S85

1. Fast road Camshafts are are often the best upgrade for an engine, but they must be installed by someone who knows what they are doing and they are not always easy to source but there might be a local firm to regrind a stock camshaft for you.
2. Turbo upgrades - A New Turbo is the most dramatic method to raise the intake air supply, this means you are able to utilize more fuel and make higher power. Typically one of the most technically difficult mods it does provide the largest gains.
3. Engine Tunes - S85 engine tuning/remapping ensures the biggest gains in terms of cost, aftermarket ECU upgrades, and Tuning boxes are all alternatives.
4. Lighter flywheels - a lower mass flywheel will improve the engines free revving nature. But not always suitable for all S85 engines.
5. Head work - The goals of porting and flowing the head are to get air flowing into the engine while removing flow restrictions and turbulence.
6. Intake Upgrades and Sports Exhausts - Note that on their own these mods will NOT ADD POWER on most cars, but they can help lift power after other mods by removing the restriction.

S85 Tuning Stages

Typical stage 1 mods often include: Sports exhaust header/manifold, Fast road camshaft, Remaps/piggy back ECU, Panel air filters, Intake manifolds, drilled & smoothed airbox.

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

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

ECU mapping should help to establish the full potential of all the mods you've fitted to your S85.

(In some cases, as the factory ECU is locked flashing is not an option, so an aftermarket ECU is the route to take, and many of these will outperform factory ECU's but make sure it has knock protection and that you get it setup properly.)

It will usually give you around 15% on NA (naturally aspirated) engines, but the outcome often differs on the mods you've fitted and the condition of your engine.

It is vital to any tuning job to force fuel and air into your S85

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

The size of bore and shape and flow rate of the Intake can make a noticeable change to fuel atomisation on the S85.

Commonly we find the throttle bodies, and intake manifold chambers are ripe for a performance upgrade, although a few makers provide reasonably well designed plenum chambers.

Increasing the S85 valve size, getting port matching and head flowing will also boost performance, this will make space for increasing the performance increase on other tuning mods.

Turbo upgrades for the S85

NA (naturally aspirated) 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 S85

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.

You'll commonly see there is a limit in the air flow sensor AFM/MAF on these engines when a lot more air is being drawn into the engine.

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

Adding a twin supercharger or turbo will make large performance gains, although hard and expensive to setup. We have this feature on twinchargers if you want to read more.

Fuelling Mods for the S85

You will need to ensure that the engine is not starved of fuel so should look at the fuelling when you start exceeding 20% of a bhp increase.Most tuners we speak with say to over specify your injector capacity.

The rule of thumb is to add 20% to the flow rate when specifying an injector, this allows for injector deterioration and allows you some 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.

S85 Performance Exhaust Upgrades

You only need to upgrade your exhaust if the current exhaust is creating a restriction in flow.

On most factory exhausts you'll find the exhaust 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.

Sports exhausts generally help improve air flow from the engine but avoid an exhaust that is too big or you could very well end up with a reduced flow rate. So generally speaking, keep to 1.5 to 2.5 inches as a rule of thumb.

Typically exhaust restrictions can be located the filters installed, so adding a faster flowing high performance aftermarket one will improve air flow, and rather than doing an illegal decat, will keep the car road legal.

Weak spots Issues & problem areas on the S85

The S85 engines are generally reliable and solid units, as long as you follow the manufacturers service schedules, and use a good quality oil to ensure longevity. Few problems should happen as long as they are regularly serviced and maintained.

Carbon build up in the head, particularly around the valves which will sap power or create flat spots, this is a larger issue on direct injection engines but should be looked out for on all engines. We have tips on removing carbon build up.

Some of our members have had issues with flat spots or glitches after applying mods and upgrades or tuning, this is not usually related to this engines design, so instead see our article on diagnosing flat spots and problems after tuning which should help you get the bottom of this issue.

Regular oil changes are vital on the S85, especially when tuned and will help extend the life and reliability of the engine.

If you would like to know more, or just get some friendly advice on Tuning your S85 engine please join us in our friendly forum where you can discuss tuning options in more detail with our 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 love to hear what our visitors have got up to and which modifications work best for you on your car. Which helps us keep our guides and tips up to date helping others with their modified car projects. Your feedback and comments are used to keep this page up to date, and help improve the accuracy of these S85 tuning guides which get regular updates and revisions.

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This article is flagged for an update, so please pass on specific tips below that I can include. All articles, and content was written by me, Waynne Smith TorqueCars founder. Some outlines are just too general so I appreciate your feedback and suggestions. This entry was filed under BMW. You can leave a response below or join our forum to discuss this article and car modification in detail with our members.

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