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 Tunes (or ECU Remaps), turbo upgrades and Fuel Upgrades you will greatly enhance your driving enjoyment.

It is considered by many to be the ultimate project engine, and it is certainly possible to achieve a high power output with relatively simple upgrades and mods.

The B48 engine has much in common with the N20 on which it was based on and also came with double VANOS Valvetronic, with more on that later.

The big brother of a B48, is the 3.0 B58 which is an inline-six engine, and provides smooth power delivery and good balance. In a joint venture between Toyota and BMW, a variation of the B58 engine was used in the fifth-generation Toyota Supra, which was introduced in 2019.

For Toyota to outsource engine production instead of evolving and developing the 2JZ into a 3JZ tells us much about the quality of the B48 (and B58) design and innovation. They needed a powerful 6 cylinder that beat the original 2JZ, and the low production volumes of the Supra meant it was more viable to look for a powerplant already developed elsewhere, the B48 option became a natural option for the lower powered variants in some regions where economy was required.

One of the highlights of the B48 is that it's turbocharged and a very responsive twin scroll turbo (TwinPower) was used, allowing a fast spool up and flexible power delivery.

Despite its power, the B48 is designed to be efficient too. It features technologies like direct fuel injection and variable valve timing to balance power and fuel economy. So depending on how you drive, the engine can sip fuel or smoke rubber but drink like a student at a frat party.

Here we review B48 tuning and report on the ultimate modifications and we welcome your comments and suggestions so we can add to and improve this article.

Please watch my video on BMW B48 mods for a complete introduction to mods & upgrades for your B48. Be sure to keep up with our latest YouTube content and subscribe.

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. With its turbocharged design and advanced technologies, the B48 engine offers an impressive balance of power and refinement.

This Turbocharged inline 4 gasoline engine ranged in power from 154hp to over 300hp. The BMW B48 engine is a 2.0-liter inline-four configuration, known for its compact size and lightweight construction.

Despite its modest 2.0 displacement (compared to the inline 6 engines), the B48 engine packs a punch, delivering robust power and torque across the rev range. There was a 1600cc version of this engine released in 2017.

They used a closed deck design and was a longer stroke engine than the N20 it replaced primarily to aid the fuel economy and engine efficiency.

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 piston head, 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.

In performance-oriented BMW models, the B48 engine enables rapid acceleration, propelling the vehicle from 0 to 60 mph in as little as 4.6 seconds, showcasing its dynamic capabilities on the road.

• 154 hp @4,500–6,500 rpm 250Nm 184 lbft @1300-4300 rpm
• 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 a good option. Too often we see people following the same tuning myths and bad advice. So let's take a realistic look at B48 upgrades and help identify the tuning mods which offer a good power gain for your money.

What about performance cams on the B48 - do you need them?

VANOS gives you a very flexible cam profile by altering the cam profile according to load/RPM and alters the intake and exhaust durations and amount of overlap on the engine and can dramatically change the torque and power output.

Vanos uses hydraulics to alter the cam angle affecting intake/exhaust and indeed the overlap duration depending on engine load and driving conditions. It effectively gives an economy cam profile and light load and low rpms, and a performance cam profile at higher RPMs and under acceleration.

The end result is a more predictable torque curve and mid range rpm response.

With double VANOS a camshaft upgrade is not worth doing, simply adjusting the VANOS points will achieve the same thing, but on other single VANOS engines out there a fast road or performance exhaust cam profile can lift performance at your chosen RPM point.

This avoids the problems associated with having to choose a stock cam profile for your engine but on single VANOS there are some benefits by upgrading the exhaust cam profile.

A note on B48 Valve Springs

Valve springs and retainers can cause problems at higher RPM's on higher power engines, so upgrading these make a lot of sense, considering their importance in controlling the valves.

At high RPM's you can have a phenomena known as valve float. They can also allow the valve motion to happen more quickly and predictably. However an excessively strong spring will cause extra wear on the camshaft due to the increased clamping pressure.

As a general rule of thumb if you are increasing your engines RPM then you also need to uprate the springs.

A set of Kelford Springs and retainers provide a 90lb seat pressure @ 11mm lift giving a little extra reliability and space to maximize the cam profile chosen.

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. 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.
3. Upgrades to turbochargers - forced induction mods are 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. Some models received superchargers as is the case on the Mini Cooper S so pully swaps are fairly simple gains for these.
4. Intercooler upgrades - rather than adding power it will the boost levels up for longer periods and resist heat soak
5. Lighter flywheel - Will subtly improve performance because it has lower rotational inertia, which means it accelerates and decelerates more quickly. This responsiveness benefits both acceleration and deceleration phases allowing you to rev match more easily and improves throttle response.

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.

Carefully think through your options and then acquire your mods and set yourself a power target to avoid disappointment.

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 DME 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 & Plug in modules seem to be the popular way to go on the B48 with popular offerings from JB4, Dinan Sport/Elite and Bootmod3.

Bootmod3 offers much control over the engine, but can be quite complex to a beginner whereas the JB4 has a more friendly interface and is a simple plug in tuner. The cost and ease of installation make the JB4 suitable for most projects, but if you have done lots of mods, want to run unusual fuel mixes or need a custom map rather than an off the shelf option the Bootmod3 is by far the most comprehensive option.

You can expect to see around 30-40hp with an improved map across most engine versions, with higher gains if you've done other supporting mods.

Aftermarket ECU's offer another route, where a more capable computer takes over from the DME for 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.

An aftermarket ECU is a good route to take for those wanting more ambitious power figures, and 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, but the end result usually depend much on the upgrades you've carried out and the condition of your engine.

Throttle Controller:

Brands like Sprint Booster offer throttle controllers that improve throttle response by reducing pedal lag. This simple upgrade adjusts the accelerator pedal's sensitivity, making the engine feel more responsive to driver input.

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.

Turbo Options

Borgwarner EFR turbos & dual TiAL wastegate. Small turbine housings flow faster and are generally better for performance if you want a wide power band.

When it comes to turbo upgrades Garrett & Pure Turbo brands are the most popular on the B48 and offer reliable power gains. The Muchboost hybrid turbo is based on the Garrett and they offer turbos for 360hp, & 400hp.

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.

Limits For Higher Power B48 Builds

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.

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

Most quote safe power figures around 320-400hp, but after that you'll need better flowing heads and install better pistons and crank to handle the power. Getting 400hp is a reasonable and easy goal on the higher power B48, and certainly possible on others if you fit a stronger crank and lower the compression ratio accordingly.

JE Pistons 82mm 9.5:1 compression ratio at stock stroke, get a balanced set to maximize your high RPM reliability and tolerance. Focus also on the quality of the wrist pin especially if you are running a much higher power figure.

The lining on the cylinder wall on the B48 is less than 1mm and is a steel plasma offering superior cooling and strength. This makes reboring a challenge and most will opt to stick with standard bore and piston ring sizes.

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.

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.

Quartz Frost offer an intercooler upgrade for the B48 which a forum member recommended to us.

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.

Stock fuel systems will usually supply fuel to the 300-350hp region but will need upgrading to push beyond that. (At the higher power levels cooling upgrades are a good precaution as well.)

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.

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 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.

If you liked this page please share it with your friends, drop a link to it in your favourite forum or use the bookmarking options to save it to your social media profile.

Please watch this video and subscribe to my YouTube channel.