BMW B48 Tuning

"All you need to know about tuning mods for your BMW B48 engine!"

The BMW B48 makes for an awesome project engine and with the right upgrades and mods like remaps, turbo upgrades and camshafts you will greatly enhance your driving enjoyment.

The B48 engine has much in common with the N20 on which it was based on and also came with double VANOS Valvetronic and a twin scroll turbo.

Here we review B48 tuning and report on the ultimate modifications.

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History, Power & Specs of the B48 Engine

The B48 shares much with the N20 which it was based on and also came with double VANOS Valvetronic and a twin scroll turbo. The design is under square and it came with quite a range of power figures.

Most of the power differences are electronic rather than mechanical, with an overboost option on some models giving another 15lbft of peak torque.

The 302hp version came with revised internals, notably a stronger crank, larger bearings and pistons and the lower compression ratio allows more boost from the larger turbo. These mods are good upgrades for the lower powered versions if you want to fit a larger turbo.

• 181 hp @5,000–6,500 rpm 290Nm 214 lbft @1,350–4,250 rpm
  2016–
• 189 hp @4,700–6,000 rpm 280Nm 207 lbft @1,250–4,500 rpm
  2014–
• 221 hp @5,000–6,500 rpm 310Nm 229 lbft @1,400–5,000 rpm
  2016–
• 228 hp @5,000–6,500 rpm 300Nm 221 lbft @1,250–4,800 rpm
  2015–
• 248 hp @5,200–6,500 rpm 350Nm 258 lbft @1,450–4,800 rpm
  255 hp @5,000–6,500 rpm 400Nm 295 lbft @1,550–4,400 rpm
  2016–
• 302 hp @5,000–6,250 rpm 450Nm 332 lbft @1,750–4,500 rpm
  2019–

Which cars had the B48 engine fitted?

B48 115 kW version

• 2020-present G20 318i

B48 131 kW version

• 2021–present F54 MINI Cooper S Clubman (B48A20M)

B48 135 kW version

• 2015–2019 F30 320i
• 2015–2019 F31 320i
• 2015–2019 F34 320i
• 2016–2018 F30 330e
• 2016–2019 F20 120i
• 2016-present F33|F36 420i
• 2017–present G30/G31 520i
• 2018-present G30/G31 530e Combined with an electric motor,  overall output is 185 kW (248 hp) and 420 Nm
• 2018–present G01 X3 xDrive20i
• 2018–present G02 X4 xDrive20i
• 2019–present G20 320i
• 2019–present G20 330e Combined with an electric motor, overall output is 185 kW (248 hp) and 420 Nm
• 2021-present G44 220i

B48 141 kW version

• BMW X1 xDrive20i
• 2020 Mini Countryman S F60

B48 145 kW version

• 2014–present F56 MINI Cooper S (B48A20A)
• 2015–present F22 220i
• 2020–present F44 220i Gran Coupe
• 2016–present F48 X1 20i
• 2017–present F39 X2 sDrive20i
• 2018–present G29 Z4 sDrive20i
• 2019–present J29 Toyota Supra (Japanese SZ models)

B48 165 kW version

• 2016–2019 F20 125i
• 2021–present UO6 223i

B48 170 kW version

• 2014–present F56 MINI JCW Hardtop and JCW Cabrio
• 2017–present F56 MINI JCW Clubman and JCW Countryman ALL4
• 2015–present F45 Active Tourer 225i
• 2016–present F48 X1 25i/28i
• 2017–present F39 X2 25i/28i
• 2019–current F44 228i Gran Coupé xDrive

B48 185 kW version

• 2015–2018 F30 330i
• 2015–2018 F31 330i
• 2015–2018 F34 330i
• 2016–present G30/G31 530i
• 2016–present F22/F23 230i
• 2016–present F32/F33/F36 430i
• 2018–present G01 X3 xDrive30i
• 2018–present G02 X4 xDrive30i
• 2020–present G01 X3 xDrive30e (PHEV Version)
• 2021-present G44 230i

B48 190 kW version

• 2016–present G11 730i/730Li
• 2017–2019 G11 740e xDrive/740Le xDrive (with an 82 kW electric motor for 240 kW)
• 2017–present G32 630i
• 2019–present G20/G21 330i
• 2019-present G29 Z4 sDrive30i
• 2019–present A90 Toyota Supra (international models since 2020)
• 2020-present Morgan Plus Four
• 2020–present G22 430i

B48 195 kW version

• 2020–present BMW F40 128ti

B48 225 kW version

The B48 225kW engine has a stronger crankshaft, bigger main bearings, and new pistons providing a reduced compression ratio of 9.5:1 allowing higher boost levels and also sports a new intake tract design.

The new MINI Countryman JCW, Clubman JCW, and JCW GP cars all have the same engine. It was shown off in May 2019.

• 2019–present F40 M135i xDrive
• 2019–present F44 M235i xDrive Gran Coupé
• 2019–present F39 X2 M35i xDrive
• 2019–present F54 Clubman JCW
• 2019–present F60 Countryman JCW
• 2020–present F56 MINI John Cooper Works GP

Tuning the BMW B48 and best B48 performance parts.

Best B48 tuning mods

Just because particular tuning mods are common on B48 it doesn't mean it is good, we shall optimum tuning mods that will give your B48 the best power gain for your spend.

Significant gains on the B48 can be made from cam upgrades. Altering the cam profile alters the intake and exhaust durations on the engine and can dramatically change the torque and power output.

Fast road camshafts commonly increase the bhp and torque through the rpm band, you may lose a little bottom end bhp but the high end rpm power will be higher.

Race camshafts, increase the high end rpm power band but as a result, the car will not idle smoothly and low end power nearly always suffers.

A Competition camshaft won't do well if driving around busy urban areas. This is because a competition cam causes a very lumpy idle, and makes the car more prone to stall or jerk along in stop start traffic, sadly though many ignore this and end up ruining a perfectly good car and having to revert back to a fast road, or OEM cam profile.

You should ideally match your bhp range to the usage of your car so for a car driven daily stick with a shorter duration B48 camshaft

Different B48 engines respond better to extreme cam durations check your engine on a rolling road.

The ecu map and fuel pump and injectors also will say much on the torque gains you'll make.

Extending exhaust or intake 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.

Please watch our video which covers the 5 principles of tuning your car. Be sure to keep up with our latest YouTube content and subscribe.

Best Engine Mods for your B48

1. Engine Tunes - engine tuning/remapping provides the most advantage in terms of cost savings,  aftermarket ECUs, and piggyback ECUs are all alternatives.
2. Fast road cams are one of the most significant mechanical changes, but they must be installed by someone who knows what they're doing and they are not always easy to source but you might find a local firm to regrind a stock camshaft.
3. Intake and Exhaust - Note that on their own these mods will NOT ADD POWER in most cases, but they can help enhance power after other mods by removing the restriction.
4. Upgrades to turbochargers - forced induction is the most efficient approach to increase air supply, allowing you to burn more fuel and make more power. It is one of the most costly upgrades but provides the best gains.
5. Intercooler upgrades - rather than adding power it will the boost levels up for longer periods and resist heat soak

BMW B48 Tuning Stages

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

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

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

Pushing fuel and air into each cylinder is vital to any performance tuning job.

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

Shape and flow characteristics of the Plenum can make a noticeable improvement to fuel atomisation and engine efficiency on the B48.

Most intake manifolds are improved through motorsport parts, although a few makers provide reasonably good intake manifolds.

Increasing the B48 valve size, carrying out B48 port enlargement and head flowing will also raise bhp and torque, and more importantly will raise potential for increasing the bhp and torque increase on other parts.

B48 mapping/flash and piggyback tuning boxes

A remap allows a tuner to unlock the full potential of all the upgrades you've fitted to your B48 and should be the last finishing mod you do *(yes we know that no tuning project is ever really finished).

Piggyback ECU's seem to be the way to go on the B48 with popular offerings from JB4, Dinan Sport/Elite and bootmod3.

You can expect to see around 30-40hp with an improved map.

Aftermarket ECU's offer another route, where a more capable ECU takes over fuel/boost/timing etc and allows fine control over these parameters allowing you to fully extract every extra BHP from your mods.

Megasquirt has been used in a few of our member BMW tuning projects to good effect, but there are many other brands out there. We would recommend you source one with a knock sensor, as we consider this vital on a highly tuned engine.

(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 30% more power on turbocharged vehicles and you can expect to see around 15% on NA (naturally aspirated) engines, but the end result usually depend much on the upgrades you've carried out and the condition of your engine.

B48 Turbo upgrades

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.

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

Discover these restrictions and install better pistons and crank to handle the power. Getting 400hp is a reasonable goal on the higher power B48, and certainly possible on others if you fit a stronger crank and lower the compression ratio accordingly.

We see many tuners spending a lot of money on turbo upgrades on the B48 only to have the engine go up in smoke soon after it's completed.

Larger upgraded turbochargers tend to experience low end lag, and little turbochargers spool up really quickly but don't have the peak end engines power gains.

In recent times the choice of turbo units is always moving on and we commonly find variable vane turbo units, where the vane angle is altered according to speed to lower lag and increase top end torque.

Twin scroll turbo units divert the exhaust gases into 2 channels and direct these at differently profiled vanes in the turbo. They also improve the scavenging effect of the engine.

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

We see 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 supercharger or additional turbo will make large power gains, although more complex to configure. We have this feature on twinchargers if you want to read more.

B48 Intercooler Upgrades

An intercooler is essentially a radiator that cools the intake air charge before it enters the engine. Install an intercooler in front of the radiator to take advantage of the copious amounts of cold air hitting it.

An effective intercooler design may provide 5% to 10% more power and withstand heat soak for a longer period of time! Some automobiles have top-mounted intercoolers that suck air in through the bonnet, which might mean that while the car is stopped, it is being hit with heated air from the engine compartment.

This can actually help economy since you may burn less gasoline because the air is warmer, and you don't want to be pulling large power numbers when stuck in traffic.

All turbocharged vehicles will benefit from an intercooler, and the typical factory installed intercoolers may be improved. The key benefit is that they stay cooler for longer and allow higher power figures for longer periods of time.

Remember that you want to suck as much air into the engine as possible, therefore if the interior core of the intercooler obstructs airflow, you will actually lose some power.

Internal flow characteristics and cooling fins are the two things that make an intercooler operate. The fins should have the most surface area, while the interior core should have a limited number of tapered bends and no internal welds to produce turbulence.

Some say that all intercoolers limit airflow, however, given the advantages of having a high-quality one installed and the small loss of airflow inherent in a well-designed intercooler, this argument falls flat.

In practise, utilising an intercooler that is too big will obstruct airflow, thus it is critical to acquire the optimum size for the application (this is something which can be discussed in more detail in our forum.)

B48 Fuelling Upgrades

Don't omit to look at the fuel system when you are increasing the bhp and torque - it makes the car more thirsty. It is important to over specify your flow rate on the injectors.

The rule of thumb is to add 20% when fitting an injector, this takes into account injector deterioration and allows a little spare capacity should the engine require 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.

Swapping out to higher octane fuel will give a power boost on the B48 as it will pick this up and adjust/trim the timing to suit.

All the following flywheel power targets will assume an injector duty cycle of 80% and a base of 58psi of fuel pressure at idle.

4 Cylinder turbocharged engines

• 58 PSI 340cc/min 200hp
• 58 PSI 511cc/min 300hp
• 58 PSI 682cc/min 400hp
• 58 PSI 1022cc/min 600hp

4 Cylinder supercharged engines

• 58 PSI 312cc/min 200hp
• 58 PSI 468cc/min 300hp
• 58 PSI 625cc/min 400hp
• 58 PSI 937cc/min 600hp

B48 Exhaust Upgrades

You should look to upgrade your exhaust if the current exhaust is creating a restriction.

On most factory exhausts you'll find the exhaust flow rate is good 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 can usually air flow out of the engine but avoid an exhaust that is too big or you might just stuff your flow rate and make things worse. So generally speaking, keep to a size of 1.5 to 2.5 inches for best results.

We see some sites recommending removing the cat from your B48 for a power gain, but in most regions this would be regarded as an off road mod only. Instead go for a better flowing sports catalyst for the same power gains as a decat, without all the legal issues you would pick up.

Typically exhaust restrictions can be traced to the catalysts installed, so adding a higher flowing performance catalyst removes the restriction. We note that performance cats perform similarly to decats and have the added benefit of keeping your car street legal, as decats or catalyst removal is illegal in most territories for road going cars.

Weak spots Issues & problem areas on the B48

The B48 engines are generally reliable and solid units, as long as you follow the manufacturer's 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 B48, 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 B48 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 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 B48 tuning guides which get regular updates and revisions.

This article was written by me, Waynne Smith TorqueCars founder, and 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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