3-7/10
Reliability
8/10
Performance
BMW N63 Engine – 4.4L Twin-Turbo V8
The BMW N63 engine is a twin-turbocharged 90-degree V8 engine that has been produced from 2008 to the present day. While BMW is often credited for producing some of the best straight-6 engines ever made, they also have an extensive history with producing V8 engines. The N63 followed up the naturally aspirated BMW N62 V8 engine which itself won Ward’s ‘Best New Engine’ and ‘International Engine of the Year’ awards in 2002.
The BMW N63 carried with it not only a few firsts for BMW but a first for engine technology overall. The N63 was BMW’s first twin-turbocharged V8 offering which is a formula that would come to define the upper-trim 5-Series, 6-Series, 7-Series, 8-Series, X5, X6, and X7 models up to the present day. It was also the first engine in the world to feature a “Hot Vee” layout, with two turbochargers mounted between the cylinder banks of the engine, allowing for a more compact package.
Overall, the N63 is known in the BMW community for a couple of things, primarily its massive power output/potential and its poor reliability. With power output ranging from 402 horsepower to 523 horsepower throughout its 5 different variants, the N63 is a serious performer that can be stretched even further with the right modifications. With that being said, the N63, especially the earlier 2008-2014 variants, are known to have a number of serious reliability issues that have tainted the engine’s reputation in the BMW community.
N63 Engine Overview
The N63 is BMW’s most recent V8 engine offering and likely their last considering the strong push to hybrid and electric power. While it is BMW’s most recent V8, the N63 is still a 15-year-old design based on the M60 V8 engine that was released in 1993. With that being said, the N63 was one of the most advanced V8 engines ever created upon its release and still is today.
The N63’s use of advanced modern engine technology, like high-performance direct injection, a “hot-vee” engine layout, and dual twin-scroll turbochargers, still puts the N63 ahead of most other current V8 engines from competitors. While the N63’s advancements have made it a formidable powerhouse, its overly complicated design has also led to several serious problems that are known to occur with the engine.
Over the course of the N63’s 15-year production run, it has received a total of 4 revisions by BMW themselves. That is excluding the S63 variants of the engine, as well as the additional 6 variants that have been produced by Alpina. Many of the N63’s revisions were to remedy some of the most serious common problems associated with the engine, including excessive oil consumption, timing chain failure, and fuel injector failure. For the most part, BMW has done a good job of addressing the problems, as the most recent N63TU2 and N63TU3 variants are largely free of issues.
The N63 has been used in a wide number of BMW vehicles between 2008 and the present day, including high-trim level F10 5-Series, F12 6-Series, F01 7-Series, G05 X5s, G07 X7s and a number of other popular BMW models.
Internals & Major Engine Components
The N63’s base design is very similar in terms of build materials and overall construction to many other BMW engines of the time with a few notable differences. Like many other BMW engines, the N63 features an alusil-lined aluminum block and an aluminum cylinder head in order to keep weight at a minimum without sacrificing strength. It is a 32-valve double overhead camshaft engine that utilizes BMW’s double-VANOS variable valve timing system. While the initial N63B44O0 variant of the N63 lacked variable valve lift, Valvetronic was added to the N63 for the first technical update.
The most groundbreaking feature of the N63’s design is its application of a “Hot-Vee” layout, which was the first of its kind, not just for BMW, but in the world. The hot-vee design was an innovative approach to packaging twin-turbochargers, which placed them in the space between the two cylinder banks of the V8. The primary goal of the hot-vee design was to reduce the overall size of the engine so that it could comfortably fit in models like the F10 and F13. The design meant that the N63’s exhaust manifolds also rested in between the cylinder banks and the partially cylinder-head integrated intake manifolds sat outside the engine.
Another consequence of the design is faster turbo spool since the charge air doesn’t have to travel nearly as far as it would on a traditional turbocharged engine. The N63 used multiple different turbochargers throughout its build cycle. The most commonly used turbo on the N63 is the Garrett MGT2256SL. With the N63TU2, BMW switched from using single-scroll turbos to twin-scroll turbos, hastening turbo spool even more. The turbos were cooled by two air-to-water intercoolers, similar to the one used on the S55.
BMW N62TU vs BMW N63
Looking at the lineage of BMW’s modern V8 engines, the N62 and N63 stand out as the most refined. Before the N63 was released in 2008, the BMW N62 was the primary V8 powerhouse used in the majority of BMW’s higher-trim, larger models from 2001 to 2010. The N62 V8 was a pretty underrated BMW engine considering its impressive factory performance and smooth power delivery. After all, it did win ‘Best New Engine’ and ‘International Engine of the Year” in 2002. However, by the late 2000s, naturally aspirated engines were slowly becoming antiquated, requiring a new design.
While the N62 and N63 are relatively similar in terms of overall engine architecture, there are some key differentiating factors between the two engines. The biggest difference between the engines is aspiration. While the N52 is a naturally aspirated V8, the N63 utilized true twin single-scroll turbochargers initially and two twin-scroll turbochargers in later variants of the engine. That obviously gives a massive horsepower and power potential advantage to the N63. Additionally, the turbocharged N63 is far more efficient and environmentally friendly than the N62.
Displacement is another difference between the two engines. While the N62 was available in four displacement options, including 3.6L, 4.0L, 4.4L, and 4.8L variants, the N63 was only offered as a 4.4L V8 in the U.S. market. Since engine tuning isn’t as significant factor with a naturally aspirated engine, BMW decided to create different displacements for the N62 to differentiate power levels for different models. With the N63, that can largely be done with altered engine tunes.
BMW N63 vs N63TU vs N63TU2 vs N63TU3
BMW N63 Customer Care Package
It is no secret that the BMW N63 is an engine with quite a few serious common problems. From excessive oil consumption to timing chain stretch and fuel injector failure, BMW recognized that they needed to step in and remedy some of the most critical issues for N63 owners. As a result, they issued a “Customer Car Package” for BMWs equipped with the N63 engine.
In essence, the care package acted similarly to a recall or service action which offered a complimentary repair of certain common failure parts on the N63 including the hot-film air mass sensors, PIEZO high-pressure fuel injectors, engine vacuum pump, fuel system low-pressure sensor, fresh air intake turbo seals, and crankcase ventilation lines. The Customer Care Package program applied to all 2009-2014 E70, E71, E72, F01, F02, F04, F07, F10, F12, and F13 vehicles with the N63B44O0 under certain conditions.
Ultimately, vehicles that fell in that year range were inspected for problematic symptoms including timing chain stretch and excessive oil consumption, and would be repaired only if they did indeed display alarming symptoms. The sweeping customer care package also extended to vehicles that had gone out of warranty, no matter how many miles were accumulated on the vehicle. If your N63 is displaying issues similar to the ones outlined in the “Problems” section of this page, it might be worth calling your local BMW dealership to see if they are still offering services under the N63 Customer Care Package.
General BMW N63 Information & Resources
N63 Engine Specs
| Configuration | 90-degree “Hot-Vee” V8 |
| Displacement | 4.4L (4,395 cc) |
| Aspiration | Twin-Turbocharged |
| Fuel System | Direct Injection |
| Engine Block | Aluminum, Closed Deck |
| Cylinder Head | Aluminum |
| Valvetrain | DOHC, Dual VANOS, Valvetronic (on later TU models) |
| Bore x Stroke | 89 mm (3.50 in) x 88.3 mm (3.48 in) |
| Compression Ratio | 9.3:1 – 10.0:1 |
| Horsepower | 402-523 HP |
| Torque (lb-ft) | 443lb-ft – 553 lb-ft |
| Redline | 6,500 RPM |
Since the BMW N63 was released in 2008, BMW has made a dizzying amount of updates to the 4.4L twin-turbo V8. That is certainly a good thing given the N63’s initial teething issues which have largely been resolved by this point. In total, the BMW N63 has been offered in 5 different variants, excluding the additional 4 M-exclusive S63 engine variants and the 6 Alpina exclusive variants. The N63’s long service life has proven that BMW is confident in the N63’s overall design philosophy. Given the state of the current automotive landscape, the N63 is likely to be BMW’s last V8 engine and it is also likely that we won’t receive any additional N63 updates or revisions either.
In this tab, we’ll cover the different variants of the BMW N63 engine, the revisions made with each variant, and the vehicles that used each variant. Due to the fact that we plan on creating a separate engine page for the S63, we’ll only be discussing the 5 non-M N63 variants on this page.
N63B44O0 – 402hp/443ft-lbs
The N63B44O0 was the first N63 variant that BMW released for the 2008 model year. The N63B44O0 was a first for BMW in a couple of significant ways. The first iteration of the N63 was also BMW’s first attempt at a twin-turbocharged V8 engine which is a formula that would come to define the upper-trim 5-Series, 6-Series, 7-Series, 8-Series, X5, X6, and X7 models up to the present day.
Additionally, the N63B44O0 was the world’s first engine to use a “hot-vee” layout, placing the two turbochargers between the engine’s cylinder banks. While the revolutionary design would present its own issues, it allowed for a more compact package. The B44O0 lacked Valvetronic variable valve lift and instead used a more traditional drive-by-wire throttle body.
- 2008– 2014 E71 X6
- 2009– 2012 F01/F02 750i/750Li
- 2010– 2012 F07 550i GT
- 2010– 2013 F10/F11 550i
- 2011– 2013 E70 X5
- 2012– 2017 F12/F13 650i
- 2011–2014 Wiesmann GT MF4
N63B44O1 (N63TU) – 444hp/480ft-lbs
After 5 years of service, the BMW N63 received its first technical update. As a result, it received a different engine designation, N63B44O1, or, more colloquially, the N63TU. As to be expected, “TU” stands for technical update and there were a number of significant changes made to the first revision of the N63 for 2013.
The most significant advancement made to the N63TU was the introduction of Valvetronic variable valve lift technology which became an increasingly more common introduction on BMW engines in the late 2010s. Valvetronic acts as an intake valve-operated throttle system which eliminates the need for the drive-by-wire system and diverter valves in the turbochargers like on the initial N63. The Valvetronic upgrade also necessitated a new cylinder head and revised VANOS system. The introduction of Valvetronic is the primary reason for the N63TU’s increase in power and torque.
Some other smaller revisions were also made to the N63B44O1’s cooling system, DME, and valve cover. The N63B44O1 added an additional onboard computer so that the computing load between the two engine management systems could be split by cylinder bank. The N63B44O1 also received a new valve cover which differentiated it from the N63B44O0.
- 2013–2015 F01/F02 750i/750Li
- 2013–2017 F07 550i GT
- 2014–2016 F10/F11 550i
- 2014–2018 F15 X5
- 2014–2019 F16 X6
- 2013–2018 F12/F13 650i
- 2013–2019 F06 650i
N63B44O2 (N63TU2) – 456hp/479ft-lbs
Following the N63TU was the predictably named N63TU, or N63B44O2, which was released in 2016 for the G12 750i and G30 M550i. Once again, the N63 saw some pretty serious revisions to the previous iteration of the engine. The primarily consisted of changes to the engine’s turbochargers, cooling system, and oiling system.
One of the most important changes came in the switch from twin single-scroll turbochargers to a pair of twin-scroll turbochargers which were initially introduced on the N55. That required additional changes to the engine’s cylinder head and exhaust. The two twin-scroll turbos enhanced the TU2’s throttle response time and decreased turbo lag.
BMW had become increasingly aware of the N63’s oil consumption issues and made efforts to improve the severity of the problem with the N63TU2. As a result, the pistons were redesigned to feature additional oiling passages to prevent excessive oil from moving away from the crankcase. The engine oil cooler was also relocated from the front wheel well to between the two banks under the turbos which eliminated an unnecessary radiator and connected it to the main cooling circuit.
To simplify and condense the intake system even further, the intake manifold was partially integrated into the cylinder head.
- 2016–2019 G11/G12 750i/750Li sDrive/xDrive
- 2017–2020 G30/G31 M550i xDrive
N63B44M3 (N63TU3) – 456hp/479ft-lbs
Of the N63 variants that we’ve covered so far, the N63TU received the fewest revisions and updates compared to the previous iteration. A lot of that has to do with the fact that BMW had solved, or mostly solved, the majority of the N63’s major issues by the time the N63TU3 was released in 2018. With that being said, there were some minor updates worth noting.
Once again, changes were made to the N63’s cooling and intake system. The biggest overall update was the N63TU’s use of an intercooler crossover tube which helped to even pressure between the cylinder banks. The N63TU3’s intake air monitoring system was also revised to reduce the complexity of the system itself. Instead of using an HFM monitoring system, the TU3 calculates air mass instead of measuring it. Additional corrections are made via the oxygen sensors.
The final small improvement was the inclusion of an overboost feature that provides additional boost, good for an extra 34 horsepower, when Launch Mode is activated.
The N63B44M3 is extremely similar to the N63B44T3 that proceeded it albeit with some minor differences. The primary difference is in the vehicles in which the engines were used. The M3 variant found its way into top-trim, yet not M-Performance models, while the T3 was used in M-Performance models.
- 2018– Present G05 X5 xDrive50i
- 2018– Present G07 X7 xDrive50i
N63B44T3 (N63TU3) – 523hp/553ft-lbs
Ultimately, the N63B44T3 is nearly identical in construction to the N63B44M3, with some minor changes made to the turbos and ignition coils. Unlike all of the other N63 variants since the initial N63B44O0, the T3 features turbochargers with diverter valves added back. The only other significant change is an upgrade to the T3’s coil packs, which were borrowed from the BMW B-Series engines. The upgraded plugs and packs have a 50% higher ignition voltage.
- 2018–Present G14/G15/G16 M850i xDrive
- 2019–Present G11/G12 750i/750Li sDrive/xDrive
- 2020–Present G30/G31 M550i xDrive
- 2020–Present G05 X5 M50i
- 2020–Present G06 X6 M50i
- 2020–Present G07 X7 M50i
- 2021–Present G14/G15/G16 Alpina B8 Gran Coupe
- 2022–Present Land Rover Range Rover (L460)
- 2022–Present Land Rover Range Rover Sport (L461)
We have compiled some of the most commonly cited BMW N63 engine problems. Unfortunately, early N63 models had quite a few of them. While the N63B44O0 and the N63B44O1 are the most problematic versions of the N63 engine, there are a few common problems that have carried through the entirety of the N63 engine range to the present day. Overall, excessive oil consumption, timing chain stretch and failure, fuel injector failures, leaking valve stems, and fast battery drainage are all common issues with the N63 and are good to know about if you drive or are looking to purchase an N63-powered BMW.
Take a look at the dropdown menu below to learn more about these problems or check out the more in-depth problem and maintenance guides featured below.
BMW N63 Engine Problems – Causes and Solutions
Of all of the common issues associated with the BMW N63, excessive oil consumption is unquestionably the most common. Ultimately, N63 excessive oil consumption is the result of multiple aspects of the engine, but the primary cause is the engine’s overall design philosophy. This issue stems mostly from the engine’s hot-vee design with the turbos being the middle of the “V” or the valley of the engine.
BMW S58 Intake Upgrades – M2, M3, M4
The excessive heat generated by the turbos and associated components causes the engine to burn oil. In addition to the overall oil consumption issue caused by the hot-vee design, the excessive heat also causes other engine issues that lead to other sources of oil consumption and oil loss. For example, the heat also causes gaskets, like the valve stem seals, to dry and degrade, leading to more oil consumption.
Excessive oil consumption varies in definition between engines, but it is generally concluded that the N63 burns, on average, around a quart per 1,000 miles. That is a lot of oil, especially when considering that that means that an extra 10-15 quarts of oil would need to be added to the engine between oil changes following BMW’s initial 15,000-mile oil change interval. The N63’s oil consumption issues have led owners to file a class action lawsuit regarding the issue which is now closed at this point. In this case, it was decided that BMW would supply reimbursement for past oil services, past oil purchases, towing or rental, and the replacement of batteries less than 3 years old.
Excessive oil consumption was much worse on the initial N63B44O0 variant of the engine, as BMW addressed the issue with the N63TU. To remedy the issue, BMW equipped the N63TU with an oil catch-can system and a secondary coolant pump. Regardless, even N63TU engines did experience excessive engine oil consumption as well in some cases.
BMW N63 Excessive Oil Consumption Symptoms
- White smoke from the exhaust
- Low engine oil light
- Engine oil smell from under the hood
One of the most serious and potentially catastrophic common problems with the BMW N63 is timing chain stretch and failure. For the N63, BMW redesigned the timing system when compared to the naturally aspirated N62 engine that preceded it. Unlike the N62, the N63 features a tooth-roller chain for each bank of the engine, which combines elements from a tooth-type chain and a roller chain. While the new system was designed to combat wear and reduce noise, it ended up being a problematic system that led to a number of timing chain issues.
In a technical service bulletin, BMW outlined that the timing chains on N63 engines have been found to stretch and wear out prematurely, resulting in premature valvetrain wear and reduced engine performance. In most cases, the N63’s timing chain guides fail, allowing the chain to skip one or multiple teeth, leading to an improper timing event that can cause a number of serious engine problems. Since the N63 is an interference engine, skipped timing can result in bent valves and other serious engine damage.
Timing chain stretch was one of the inspection items outlined in the N63 Customer Care Package and if the timing chain was found to be worn or stretched, BMW would replace the chain and all associated parts free of charge. Unfortunately, discretion about honoring the CCP is not up to the dealer and the repair was only covered for vehicles covered by factory warranty.
As with many of the other common problems associated with the 4.4L V8, replacing the timing chains is a very in-depth job that can add up quickly in terms of repair costs. Depending on if there is any other engine damage caused by a stretched timing chain, the repair can range anywhere between $5,000-$12,000 by a certified BMW repair facility.
N63 Timing Chain Stretch/Failure Symptoms
- Rough idle
- Poor engine performance or a sudden and serious lack of power
- Metallic clanging noises from the engine bay
- Low engine oil light
Unfortunately, a stretched or failing timing chain won’t typically present many warning signs before a skipped timing event occurs, at which point internal engine components can already be seriously damaged. One of the most common early symptoms is a metallic clanging noise coming from the engine bay due to the timing chains’ excessive slack. Rough idle and poor engine performance is another common indicator of timing chain issues.
Fuel injector failure is a common issue on direct injection BMW engines from the late 2000s. Similar to the N63, other engines like the direct-injected BMW N54 also had extensive issues with its high-performance Piezo injectors. N63 fuel injector failure was such a common problem, even at relatively low mileage, that BMW extended the fuel injector warranty to 10 years/120,000 miles, whichever came first. Fuel injector replacement was also a service item that was part of the N63’s Customer Care Package.
In most cases, the injectors either begin leaking from their enclosure or get clogged, preventing them from delivering an adequate amount of fuel to the engine. Some N63 owners have reported that injectors can fail as early as 20,000 miles, with some owners reporting that they’ve had to replace their injectors every 8 months. While that is more of a rarity, it goes to show how severe N63 fuel injector issues can be.
In most cases, not all 8 injectors will fail at the same time, with one or two cylinders typically being problematic at a single time. With that being said, it is generally advised to replace all 8 injectors, coil packs, and spark plugs at the same time to avoid additional headaches in the future and save a bit on the overall replacement cost. Regardless, replacing N63 fuel injectors is an expensive endeavor. If your BMW isn’t covered under warranty and the dealer isn’t willing to work out a deal regarding the Customer Care Package, the total replacement for all 8 N63 fuel injectors can cost in the ballpark of $5,000.
As an aside, BMW has revised the design of the N63’s fuel injectors multiple times since 2010. If you do need to have your fuel injectors replaced, it is important to ask for the most up-to-date parts in order to limit future problems.
N63 Fuel Injector Failure Symptoms:
- Engine burning excessive amounts of oil
- Rough idle or rough engine performance under acceleration
- Fouled spark plugs
- Misfires
- Overfueling/underfueling engine codes
- Spark plug failure engine codes
One of the nearly guaranteed maintenance items that you’ll have to do on your BMW N63 is a valve stem seal replacement. It is pretty well known in the N63 community that replacing valve stem seals is nearly a certainty at some point in the engine’s lifecycle, and excessively worn valve stem seals tend to become an issue for N63 owners around the 60,000 to 100,000-mile mark.
The primary job of the valve stem seals is to allow a controlled amount of oil to lubricate the valve stem as it moves in the valve guide. Additionally, they act as a barrier that prevents engine oil from contaminating the air/fuel mixture in the engine’s combustion chamber. When valve stem seals degrade, they allow oil to leak into the combustion chamber where it burns off and creates smoke and adds to the N63’s existing excessive oil consumption issues.
This is yet another issue that can be directly linked to the N63’s hot-vee design. Due to the fact that the turbos and exhaust manifolds are so close to the cylinder head, the excess heat created by those components causes the rubber valve stem seals to degrade faster than they would on a traditional turbocharged engine. As a result, the valve stem seals tend to have to be replaced at a much lower interval than most other engines. The issue is most prominent in the initial N63B44O0 engine produced between 2008-2014.
Unfortunately, replacing N63 valve stem seals is an extremely in-depth job that typically requires around 40 hours of labor which makes up most of the cost of the repair. While N63 valve stem seal replacements used to be an engine-out service, BMW now recommends that mechanics leave the engine in the car to perform the service. However, the job does require specialty tools and some pretty extensive engine knowledge, so it is a job that is typically best left to professionals. Most N63 owners that have had the service done say to expect a $3,500-$4,000 repair bill for parts and labor.
As a temporary fix, some N63 owners have said that putting AT205 reseal additive into your engine oil can help to reseal your valve stem seals which can help with oil consumption in the short term. With that being said, it is a temporary band-aid and the seals will have to be replaced eventually.
Symptoms of Leaking N63 Valve Stem Seals
- Smoke from the tailpipe when starting or aggressively accelerating and decelerating the engine
- Excessive engine oil consumption
- Spark plugs fouled with engine oil
Leaking N63 valve stem seals is often a tricky issue to diagnose due to the fact that there are numerous other common causes of N63 engines burning oil. For instance, crankcase ventilation system issues are also common on the N63, and another problem that presents similar symptoms to leaking valve stem seals. For that reason, you’ll likely have to have your vehicle diagnosed before the exact issue is identified.
Another very common issue with N63-powered BMWs is fast battery discharge. That essentially just means that the vehicle’s battery dies extremely quickly and frequently when not driven for a short amount of time. While many of the N63’s other issues were largely worked out with the later TU variants of the engine, fast battery drainage stayed an issue and still remains an issue to this day. With that being said, it is still a more prevalent issue on the earlier engines.
There are a few reasons why battery discharge is so prevalent on the N63, and most of them are tied to the N63’s EfficientDynamics system, which was designed to provide the best fuel efficiency possible. As part of that system, all N63-powered BMWs are programmed to only charge the vehicle’s battery when coasting, meaning that the battery doesn’t charge while the car is accelerating like most other vehicles. That never allowed the batteries to charge fully, causing them to die frequently.
In addition to the problems caused by the EfficientDynamics system, the N63’s turbochargers are also to blame for the N63’s battery issues. Due to the N63’s hot-vee layout, the cooling system needs to operate to cool the turbos even after the engine is off following a period of spirited driving. As a result, the cooling system draws more power than the batteries can handle.
Because the batteries die so frequently, BMW recommends that you replace the battery on your N63 BMW every oil change or 10,000 miles. That’s pretty ridiculous, considering the cost of BMW batteries. BMW attempted to resolve the issue in multiple ways over the years. Initially, they attempted to replace the stock batteries with deep-cycle AGM batteries, then they tried to increase the battery’s size from 90-Ah AGMs to 105-Ah batteries. Unfortunately, that is only a short-term solution that doesn’t solve the issue.
There isn’t a true fix for the issue, even today, and most N63 owners have accepted the fact that rapid battery discharge is one of the downsides of living with the N63 engine.
N63 Problems & Maintenance Guides
BMW N63 Engine Problems – Causes and Solutions
We have the most comprehensive resources for N63 performance upgrades. This section includes some of the most popular, cost-effective, and value-focused modifications for the BMW N63 engine. As with most modern turbocharged BMW engines, there is no shortage of ways to squeeze quite a few extra ponies out of your N63 engine. That is amplified even further by the fact that the N63 is a true twin-turbocharged engine that is capable of withstanding far more horsepower than it produces from the factory. From tuning information to performance parts suggestions, we have you covered as far as BMW N63 modifications are concerned.
Click on each modification to get a brief rundown of the mod, the benefits, and our best product recommendation. Additionally, we have a dedicated 500+ Horsepower BMW N63 for Under $1,500 Guide if you are looking for more detail on the subjects covered below.
How to Build a 500+WHP BMW N63 for Under $1,500
Tuning is unquestionably the most important aspect of upgrading and modifying the BMW N63 engine as it provides the most significant power and torque gains while also setting up the engine to get the most out of any additional performance parts that you decide to add in the future. Ultimately, there are two main tuning paths for the N63 which include piggyback tunes and backend flash tunes.
If you aren’t familiar with the difference between an N63 piggyback tune and an N63 flash tune, an N63 flash tune (like BM3 provides) essentially rewrites the factory DME programming. This allows the tune to gain complete control of engine tuning parameters like boost, fueling, timing, and load.
The other popular option is an N63 piggyback tune. Unlike a flash tune which augments the factory DME parameters, a piggyback tune simply changes the boost parameters of the engine and allows the factory DME to sort out the rest. While some people argue that N63 piggyback tuning is inferior, options like the JB4 come with plenty of functionality and have the ability to switch maps on the fly. In fact, the Burger Motorsports JB4 is still the most common tuning solution for the N63 to this day.
There is no doubt that a quality N63 tune is the best bang-for-buck modification available for the BMW N63 engine, as it yields the best horsepower per dollar ratio of any modification out there. For around $700, a JB4 can provide power gains of up to 100 horsepower without any additional performance mods. That number gets even higher when paired with the other modifications listed here.
Best BMW N63 Tuning Solution
For most turbo BMW engines this is our second recommended mod following a tune. Although, in the case of the N63 this mod may not be worth it to some. The OEM intake design on the N63 is very efficient. Performance air intakes only offer performance benefits if the engine is struggling with air flow. This should not be an issue on a stock turbo N63.
However, a performance intake may add a few horsepower for those pushing stock turbos towards their upper limits. While horsepower gains tend to be minimal from an upgraded N63 intake system, they do provide soem other notable performance benefits like faster turbo spool and marginally quicker throttle response. Regardless of power, the intakes are almost worth it for the sound alone (open intakes/filters). If they were a couple hundred dollars we would absolutely recommend them for sound. However, most of the N63 intakes range from about $500-$1,000+.
It’s a lot to spend to hear some louder turbo noises and maybe gain a few horsepower. They do sound phenomenal though. Check out our BMW N63 intake upgrade guide for more info.
N63 Intake Upgrade Benefits
It is unlikely a bone-stock N63 will gain any power at all from an “upgraded” intake system. However, as power is increased via tunes and other bolt-on parts the stock N63 intakes may begin falling short. As such, upgraded dual cone intakes may provide some performance benefits for modded N63s, especially when heavily modded with upgraded turbos. A few benefits include the following:
- Approx. 5-10whp and torque when stock
- Faster turbo spool
- Increased air flow and less restriction
- Quicker throttle response
- Enhanced intake induction sound
Best BMW N63 Upgraded Intake Kit
BMW N63 Intake Upgrade Guide
BMW N63 Upgraded Intake Guide
OEM N63 catalytic converters (cats) in the downpipes are intended to reduce emissions. However, restrictive cats also reduce power and performance. Turbos rely on the pressure drop from pre to post-turbo in order to spool and build boost. Reducing pressure post-turbo (referred to as back-pressure) allows the exhaust gases to accelerate faster as they look to escape. Therefore, reducing back-pressure allows a turbo to spool faster and build more boost. That directly results in serious power and torque gains, between 30-50 horsepower and a similar amount of torque in most cases.
Less back-pressure results in better power and performance gains. Catless downpipes provide less back-pressure compared to high-flow catted options. Therefore, catless DP’s will result in the best power gains and quickest turbo spool. However, catless options do come with their own downside. Removal of cats may cause your N63 to fail state inspections and/or emissions testing. For those concerned with emissions you might consider opting for the high-flow catted DP’s.
If emissions are not a concern then we highly recommend selecting truly catless downpipes. They are typically less expensive than catted options and provide the best power gains. Although, an N63 high-flow catted DP is a solid choice for a balance of performance and cleaner emissions.
Yet another benefit to upgraded downpipes are the intoxicating sounds. Expect catless DP’s to add quite a bit of noise on cold starts. Additionally, applying heavy throttle provides a satisfying deeper, aggressive note. However, the N63’s exhaust stays relatively quiet and does not invade the cabin during normal cruising.
BMW N63 Downpipe Upgrade Benefits
- 30-50whp with catless DP’s (10-20whp with high-flow catted)
- Similar torque gains
- Faster turbo spool
- Better top-end power and boost
- Excellent sounds
Best N63 Catless Downpipe
BMW N63 Upgraded Downpipes Guide
BMW N63 Upgraded Downpipes Guide
E85 mixtures are highly recommended not only for the N63, but also for any performance engine. E85 has countless benefits, especially when pushing the N63 past stock boost levels. First, it burns cooler than gasoline. This results in lower temperatures within the cylinders. Second, it burns at a stoich of 9.765 compared to 14.7 for gasoline. As such, more fuel must be injected into the cylinder.
Cooler burn and more fuel result in a lower chance of knock or pre-detonation. This allows the N63 to run more boost and possibly more aggressive ignition timing. Therefore, E85 is generally safer for the engine, runs cooler, and adds power. All great things. E85 also has a few downsides that should be noted. Fuel efficiency decreases (though it should even out given the lower cost of E85 vs 91/93 octane). Your tune must also compensate for the E85 mix. The JB4 tune is able to accommodate up to 30% E85. Anything higher would require the use of a back-end flash tune.
Best N63 Flex Fuel Kit
N63 Bolt-On Mod Guide
How to Build a 500+WHP BMW N63 for Under $1,500
For our last modification recommendation, we’ll step out of the bolt-on category and discuss something a bit more extreme. Obviously, turbocharger upgrades aren’t for the faint of heart or wallet, as it is a very in depth job with quite a few serious considerations. Since the topic of upgraded turbochargers is such an expansive one, we won’t go into too much detail here, but if you want to learn more about upgraded BMW N63 turbochargers, we’ve written a full guide on the subject.
BMW N63 Upgraded Twin Turbo Guide
Before going into N63 turbocharger upgrades in detail, it is important to consider the N63’s limits. Earlier N63 variants can’t support as much power and torque as later variants, with the N63 maxing at around 600wtq and the N63TU maxing somewhere around 650wtq. Ultimately, it’s important to ensure you’re running a proper tune, fueling, and supporting mods. If you’re targeting 600+whp we highly recommend running meth, race gas, E85 mixtures, or a combination of those. Additionally, you may consider tuning to limit torque on the lower-end and mid-range unless you’re building your engine.
With that being said, there are some very notable benefits to running upgraded BMW N63 turbochargers. Upgraded BMW N20 turbochargers tend to shift the power and torque curve right, meaning that they sacrifice some low-end torque and power for more top-end power. That is actually a good thing for engine health, as the less low-end torque the better.
Low-end torque is very hard on an engine. At lower rpms, the pistons are moving slower, which subjects the cylinders to greater stress. The slower piston movement also allows for more time for the cylinder to potentially pre-detonate, which is never good news when pushing the limits.
Additionally, larger turbos can limit excessive boost pressure while still making more power than the factory turbo at a given psi. The science behind that claim is pretty complicated and would take up too much screen real estate here, but the decreased load from a larger turbocharger lessens the strain on internal components.
Overall, if you are trying to push your N63 to its limit, upgraded turbochargers are a key piece to the equation.
Additional N63 Performance Guides
How to Build a 500+WHP BMW N63 for Under $1,500
BMW N63 Upgraded Twin Turbo Guide
BMW N63 Upgraded Intake Guide
BMW N63 Upgraded Downpipes Guide
This engine page covers quite a bit of information about the BMW N63 engine and the various performance upgrades, power levels, general maintenance, problems, and reliability associated with it. If you are looking for a quick answer to a quick question about the BMW N63, take a look at the FAQs listed below.
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How much power can the N63 handle?
The BMW N63 is capable of handling upwards of 700whp and around 600wtq on the stock block and internals. While peak horsepower does play a part in how far you can push your N63, peak torque is really the main consideration, as low end torque is what can be truly damaging to the engine’s internals. It is also important to mention that the N63TU and other later iterations of the N63 can handle more power and torque than the initial N63B44O0. Due to the fact that the N63TU received a forged crank and rods. Additionally, the N63tu features oil spray nozzles to help cool the piston crowns. This allows the later engines to push closer to 650-700wtq.
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Is the BMW N63 the same as the N62?
No, the BMW N63 is not the same engine as the N62. Despite both being BMW V8 engines, there are a number of important distinctions between the two engines. The most important distinction between the two is the N63’s use of two turbochargers. While the N62 was a naturally aspirated V8, the N63 is a twin-turbo V8. As a result of the N63’s hot-wee layout, the block and cylinder head design were changed dramatically for the N63. Additionally, the N62 came in a range of displacements from 3.8L to 4.8L. In contrast, the N63 was only offered as a 4.4L V8 in the United States, with an additional 4.0L version made specifically for the Chinese market.
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How reliable is the BMW N63?
Ultimately, the reliability of the N63 engine really depends on which variant you are talking about. The initial N63B44O0 variant of the N63 is often considered one of the least reliable engines that BMW has ever made. Many of the most common problems with the N63B44O0, including timing chain stretch, valve stem seal wear, and fuel injector failure were very expensive to repair and potentially catastrophic to the engine in some cases. With that being said, BMW steadily made upgrades to N63 over the course of its decade-long build cycle to remedy many of the issues prevalent on the earlier variants. Today, the N63 is considered reliable, with very few serious issues plaguing the N63TU2 and N63TU3 variants.
8020 Media N63 Videos
Other Helpful N63 Videos
Outside Resources
We have a number of guides on specific BMW N63 topics – check out all of our N63 content below or use the tabs to find our articles on specific modifications, and so on. However, there is also a ton of good content elsewhere around the N63. Check out a few of our favorites here:
All BMW N63 Engine Content
How to Build a 500+WHP BMW N63 for Under $1,500
BMW N63 Engine Problems – Causes and Solutions
BMW N63 vs N63TU vs N63TU2 vs N63TU3
BMW N63 Upgraded Downpipes Guide
BMW N63 Upgraded Intake Guide
BMW N63tu Stock Twin Turbos Max Boost
