MENUTuning the BMW B47
"All you need to know about tuning and performance parts on the BMW B47 engine!"
Carref prides itself on providing the latest tips and guides to your modification project.
This pages aim is provide a guide to B47 tuning and report on the optimum modifications.
BMW B47 are popular tuning projects and with the optimum tuning mods like remaps, turbo kits and camshafts you will dramatically maximize your driving experience.
We rely on our visitors to pass on tips and tell us about their projects and what worked on their car, and this article is the culmination of the feedback we have received. First let us look at the history and specs of this engine and then consider which tuning modifications work best on it.
History of the Engine
The fuel pressure is rated to around 2000bar - typical for a direct injection diesel engine and turbos are the twin scroll variety which have variable geometry inlets.
We also see double VANOS used on the B47 which gives a nice power band. Each cylinder has 4 valves and are designed to warm up very quickly, helping reduce emissions and particulate filter build up.
B47D20 (85 kW version)
114 hp @ 4,000 rpm 270 Nm (199 lbft at 1,250–2,750 rpm
- 2015–2019 F30/F31 316d
- 2020–present G20 316d
B47D20 (110 kW version)
148 hp @ 5,000 rpm 236lbft-266lbft
- 2014–2016 F10 518d
- 2014–present F45 218d Active Tourer
- 2015–present F20 118d
- 2015–present F22 218d
- 2015–present F25 X3 sDrive18d
- 2015–2019 F30/F31/F34 318d
- 2015–present F32/F36 418d
- 2015–present F48 X1 sDrive18d
- 2015–present F54 MINI Cooper D Clubman
- 2017–present F39 X2 sDrive18d
- 2017–present F60 MINI Cooper D Countryman
- 2019–present G20 318d
- 2019–present F40 118d
B47D20 (125 kW version)
168 hp @ 4,000 rpm 360 Nm (266 lbft at 1,500–2,750 rpm
- 2015–present F56 MINI Cooper SD
B47D20 (140 kW version)
188 hp @ 4,000 rpm 400 Nm (295 lbft at 1,750–2,500 rpm
- 2014–2016 F10/F11 520d
- 2014–present F26 X4 sDrive20d
- 2014–present F45 220d Active Tourer/220d Gran Tourer
- 2015–present F20 120d
- 2015–present F22/F23 220d
- 2015–present F25 X3 sDrive20d/xDrive20d
- 2015–2019 F30/F31/F34 320d
- 2015–present F32/F36 420d
- 2015–present F48 X1 sDrive20d
- 2015–present F54 MINI Cooper SD Clubman
- 2016–present G30/G31 520d
- 2017–present F39 X2 xDrive20d
- 2017–present F60 MINI Cooper SD Countryman
- 2017–present G01 X3 xDrive20d
- 2018–present G32 620d Gran Turismo
- 2019–present G20 320d
- 2019–present F40 120d xDrive
- 2019–current F44 220d Gran Coupé
B47D20 (165 kW version)
221 hp @ 4,400 rpm 450 Nm (332 lbft at 1,500–3,000 rpm
202 hp @ 4,000 rpm 430 Nm (317 lbft at 1,750–3,000 rpm
- 2015–present F20 125d
- 2015–present F22 225d
- 2015–2018 F30/F31/F34 325d
- 2016–present F32/F33/F36 425d
B47D20 (170 kW version)
228 hp @ 4,400 rpm 332lbft - 369lbft
These have a clever multi stage turbo setup and fuel pressure is 2500bar.
- 2015–2018 X5 F15 sDrive25d/xDrive25d
- 2016–present F48 X1 xDrive25d
- 2017–present G01 X3 xDrive25d
- 2017–present G30/G31 525d
- 2018–present F39 X2 xDrive25d
- 2018–present G02 X4 xDrive25d
Tuning the BMW B47 and best B47 performance parts.
What are the most effective B47D20 parts
When talking about the best optimum for your B47D20 engine, we are going to concentrate on the tuning parts that give the best value for money.
Significant gains on the B47D20 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 normally increase the power throughout the rpm band, you could sacrifice a little bottom end power but the high end rpm power will be lifted.
Competition cams, increase the high end rpm power band but as a result the car will not idle smoothly and low end power nearly always suffers.
In a typical daily driver must carefully try to optimize your power band to your usage of the car.
I'd never find a B47D20 Motorsport camshaft is a pleasure to live with when driving around busy urban areas.
Each engine version responds better to mild camshaft durations than others.
The ECU mapping and injectors and fuel pump also will make differences on the bhp gains you'll make.
Altering 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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How to tune your car
- Improve the handling
Focus on Suspension improvements, such as coilovers and make sure the bushings are in good order and that the alignment is correct. Then focus on improving the brakes, with a big disk brake conversion kit and fast road brake pads.
- Remove restrictions
Focus on the intake and exhaust with filters being the common point of restriction in a tuned car. Intercoolers may also become restrictive on turbo engines so this may also need to be uprated.
- Burn more fuel & air
Increase the fuelling so it matches the air coming into the engine. The ratio is important so you need to improve the fuel pump and injectors, so the head mods, big valve conversions, fast road camshafts and forced induction upgrades extra supply of air is adequately met.
- Test and replace any weak parts
Weak areas are commonly the clutch, the turbocharger and pistons and crankshaft in a highly tuned engine. Makes sure these components will cope with your power aspirations.
- The Tune or Remap
A cars ECU controls the fuel, timing, spark and even the turbo in some cases, so to fully extract your gains you should remap the car last and this will fully release the power. Some cars are easy to map, and others require piggyback ECU's or aftermarket ECU's but this is the most vital step of your tuning project.
Modifying to Stage 1:
Fast road camshaft, Remaps/piggy back ECU, Drilled & smoothed airbox, Intake headers, Sports exhaust manifold, Panel air filters.
Modifying to Stage 2:
Fast road cam, fuel pump upgrades, Sports catalyst & performance exhaust, high flow fuel injectors, induction kit, Ported and polished head.
Modifying to Stage 3:
Competition cam, Crank and Piston upgrades to alter compression, Internal engine upgrades (head flowing porting/bigger valves), Engine balancing & blueprinting, Adding or Upgrading forced induction (turbo/supercharger), Twin charging conversions.
Remaps should help to fully realize the full potential of all the upgrades you've done to your B47D20.
It will usually give around 30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but the outcome often vary depending on the upgrades you've carried out and the condition of your engine.
Feeding more air into your B47D20 is the aim to any engine upgrade project.
The intake plenum take the air from the filter and allow it to be pulled into the engine and mixed with fuel.
Structure and flow characteristics of the Intake manifold can make a big change to fuel atomization on the B47D20.
Many mass produced engine plenum chambers are in desperate need of aftermarket parts, although some manufacturers provide decently flowing plenum chambers.
Fitting big valve kits, doing a bit of port matching and head flowing will also raise torque, and as an added benefit will raise potential for increasing the torque increase on other upgrades.
Which turbo upgrades are best?
We've seen guys spending a lots of money on turbocharger upgrades on the B47D20 only to watch the car catastrophically fail just after it's used in anger.
BMW use single scroll Bosch-Mahle turbos equipped with variable geometry inlets and this pulls great from low RPM and gives a good amount of torque throughout the rev range.
Larger upgraded turbo units tend to experience low end lag, and little turbo units spool up much more quickly but won't have the top end torque gains.
In the last 10 years the choice of turbo chargers is always developing and we commonly find variable vane turbo chargers, allowing the vane angle is altered according to speed to lower lag and increase top end bhp.
Twin scroll turbo chargers divert the exhaust flow into a couple of channels and push these at differently angled vanes in the turbo. They also increase the scavenging effect of the engine.
You'll commonly see there's a limitation in the air flow sensor (AFM/MAF/MAP) on these engines when considerably more air is being drawn into the engine.
We see 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor sapped torque at a much lower level.
Adding a supercharger or additional turbo will make large bhp and torque gains, although more difficult to configure. We have this guide to twinchargers if you want to read more.
Fuelling
When you raise the bhp and torque you will need to look at to the fuel system.
More bhp and torque needs more fuel. 
We strongly recommend you to over specify your flow rate on the injectors.
As a rule of thumb add 20% when buying an injector, this accounts for injector deterioration and gives 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.
Choosing the right performance exhaust
One of the most common mistakes and problems we see in tuning projects is usually down to the exhaust, or rather a poorly chosen exhaust for your engine.
You may need to improve your exhaust if your exhaust is creating a restriction in flow but this is unlikely as the BMW diesel exhausts are known to flow pretty well from the factory.
On most factory exhausts you'll see the 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.
But if your exhaust is too large, ie: over 2.5 inches bore, you will lose a great deal of your flow rate and end up lacking power and torque.
Common exhaust restrictions can be traced to the catalyst installed, so adding a higher flowing high performance alternative will help avoid this restriction.
Weak spots Issues & problem areas on the B47D20
The B47D20 engines are generally reliable and solid as long as they are regularly serviced and maintained.
Regular oil changes are vital on the B47D20, especially when tuned and will help extend the life and reliability of the engine.
DPF can be an issue on short journeys and lots of cold starts, so read our guide on cleaning a DPF to keep it in good condition.
For more information on Tuning your B47D20 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 upgrades work best for them on each model of car. Comments are used to improve the accuracy of these B47D20 articles which are continually updated.
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