BMW B58 High Pressure Fuel Pump Upgrade Guide
Meet Austin
Austin graduated from the University of Colorado Denver in 2021 with a degree in technical writing and remains in the Denver area. Austin brings tons of automotive knowledge and experience to the table. Austin worked as a Technical Product Specialist at BMW for over 5 years and drives a heavily modified E30 325i with a stroker kit, all of which he built from the ground up.
One of the first roadblocks to making massive power from the BMW B58 straight-6 is the factory high-pressure fuel pump. While the factory B58 high-pressure fuel pump is a pretty capable piece of kit compared to the HPFPs found on older BMW turbocharged engines, it still taps out at around the 450whp mark on 93 octane fueling and 410-420whp on an E30 ethanol blend, limiting the peak potential of even the stock twin-scroll turbocharger.
If you are considering more substantial power upgrades, like an upgraded stage 2 or stage 3 turbocharger, you’ll need to think about either port injection or a B58 high pressure fuel pump upgrade to keep up with fueling demands. While port injection is a solid option for B58 owners that are planning on truly going power crazy, an upgraded B58 high pressure fuel pump is the easiest, most effective, and safest way to achieve adequate fueling for a 600-700whp B58 build.
In this guide, we’ll cover everything that you need to know about B58 high pressure fuel pump upgrades including the pros and cons of upgrading, the fueling limitations of some of the most common pumps on the market, and our recommendations.
Stock BMW B58 High Pressure Fuel Pump Limits
Unlike the stock high pressure fuel pumps on previous engines like the N54 and N55, the B58’s factory high pressure fuel pump is pretty capable in comparison. While limits always vary from engine to engine, we have enough data to safely say that the factory B58 high pressure fuel pump is limited to around 450whp when using 93 octane pump gas. Due to the fact that using alternate fueling, like ethanol, puts even more strain on the factory fuel system, the limit of the factory pump is reduced to only around 420-435whp when running a low-content ethanol mix like E30.
- Stock B58 HPFP Pump Gas Limit – 450whp
- Stock B58 HPFP E30 Limit – 420whp
The factory pre-TU B58 high pressure fuel pump’s primary limitation is the amount of fuel that it can physically flow. While the later B58TU received an upgraded fuel system (which we’ll talk about in a minute), the pre-TU HPFP was designed for the Gen 1 B58’s 200-bar fuel system. That roughly equates to 2,900PSI. While that is quite a bit of pressure, it isn’t enough to keep up with the fuel demands when boost is maxed on the factory turbo, if you introduce an upgraded turbo to the equation, or want to run a high-content ethanol blend.
Stock BMW B58TU High Pressure Fuel Pump Limits
When the Gen 2 B58TU arrived on the scene in 2018, one of the most notable changes between the Gen 1 and Gen 2 engines was the fuel system. While the previous Gen 1 B58 utilized a 200-bar fuel system, the Gen 2 B58 received a heavily reworked high pressure fuel system that was capable of 350-bar or 5,075PSI.
The main component that made that possible was an upgraded high pressure fuel pump from the factory. As a result of being capable of supporting nearly twice the fuel pressure of the initial Gen 1 fuel system, the Gen 2 B58TU is also able to support quite a bit more power than the earlier B58 variant.
- Stock (Gen 2) B58TU HPFP Pump Gas Limit – 520-540whp (Octane Limited)
- Stock (Gen 2) B58TU HPFP E30 Limit – 500-550whp
Overall, the B58TU high pressure fuel pump is capable of supporting around 100 additional horsepower over the standard Gen 1 B58 HPFP. In fact, the Gen 2 B58 pump is so effective that you’ll hit the octane limit of 93 octane pump gas before reaching the flow limitation of the pump itself. The B58TU high pressure fuel pump’s high flow capabilities combined with its compatibility with the Gen 1 B58 make it a common and popular upgrade for the earlier engine, but we’ll go into more detail about the B58TU high pressure fuel pump in the sections to come.
BMW B58 Fuel Pump Upgrade vs Port Injection
One of the most commonly asked questions about B58 fuel system upgrades is port injection vs a fuel pump upgrade. Both options set out to accomplish the same goal; provide additional fueling to allow for higher boost pressure, ignition timing, and ultimately more power. So, what is the difference between the two, and which is better for your goals?
While a B58 high pressure fuel pump upgrade is pretty self-explanatory, port injection isn’t as straight forward. As you probably know, the BMW B58 uses a high pressure direct injection system meaning that the factory injectors deliver fuel directly to the combustion chamber without traveling through the intake valves. Direct injection systems have been used on BMW engines since the N54 in 2007 and are far more efficient than other fuel injection systems like port injection on their own.
In contrast, a port injection fuel system places the injectors behind the intake valves, where fuel enters the combustion chamber through the valves themselves. Port injection is an older, and often more reliable, way of fuel injection which was a mainstay on vehicles until relatively recently.
However, when we talk about port injection as supplemental fueling, we aren’t talking about replacing the factory direct injection system altogether. Instead, it is possible to add port injection in conjunction with the B58’s direct injection system to essentially double (or triple) the amount of fuel entering the combustion chamber.
When Is B58 Port Injection Better?
Adding port injection to the B58 is typically done in one of two ways; either through an intake manifold spacer or through a full port injection intake manifold replacement. While we won’t get into too much detail about B58 port injection here, it is important to note that installing a port injection system is a much more in-depth and complicated modification than a fuel pump upgrade, as it is more complicated to install and requires its own auxiliary controller and tuning.
With that being said, port injection can ultimately support more power than an upgraded B58 high pressure fuel pump alone. A B58 port injection system adds 6 additional injectors, on top of the 6 from the direct injection system, which can be upgraded to whatever size you want. For that reason, port injection is the better option if you are shooting for power figures above the 700whp threshold.
While there are some notable benefits, port injection systems are extremely complicated to tune in conjunction with the factory direct injection system, with potentially disastrous consequences if something goes wrong with the tune.
Since port injection isn’t controlled by the factory DME and is instead controlled by an additional controller, it is possible for there to be latency between the DME’s fueling instructions and the additional controller. In that case, the port injection system can continue dumping fuel into the cylinders even if the DME is telling the DI system to cut fueling. With just a B58 high pressure fuel pump upgrade, that isn’t a possibility, making it the safer option overall.
If you are interested in reading more about B58 port injection including some of our recommendations for the best kits available on the market, take a look at our BMW B58 Fueling Modifications Guide.
When Is a B58 High-Pressure Fuel Pump Upgrade Better?
While the 700-750whp mark is where even an upgraded B58 high pressure fuel pump upgrade struggles to keep up without the help of additional auxiliary fueling, an HPFP upgrade is the better choice if you are aiming for a power goal anywhere below that. For most B58 owners who are planning on upgrading to a stage 2 turbocharger, an upgraded B58 HPFP will likely take you to the edge of your given turbo’s capabilities.
High pressure fuel pump upgrades are preferable if you are shooting for an appropriate power goal for a few reasons. One of the main reasons is that they are relatively easy to install. Compared to a port injection system that requires you to remove the intake manifold, high pressure fuel pump upgrades are a plug-and-play swap with the factory pump which is relatively easy to access.
Another major benefit is the simplicity of a B58 HPFP upgrade. Unlike with port injection, a HPFP upgrade keeps direct injection the only source of fueling. That means that there aren’t any additional fuel lines, nozzles, or injectors that make installation difficult. Along those same lines, you don’t have to worry about any of those auxiliary components failing either, which can be a major issue for a port injection system.
Finally, tuning is much easier with a high pressure fuel pump upgrade. Most major tune suppliers provide OTS support for B58 fuel pump upgrades, making tuning very simple.
B58/B58TU High Pressure Fuel Pump Upgrade Options
Upgraded B58 high pressure fuel pumps are designed to flow a much higher volume of fuel, allowing you to run more aggressive ethanol blends and support higher power goals. Fortunately, there are number of B58 high pressure fuel pump options available, some from aftermarket companies, and some from other BMW engines as well. Due to the fact that upgraded fuel pumps are designed differently for the pre-TU and TU fuel systems, we’ll separate the options below into B58 and B58TU categories.
It is also important to note that the B58TU is still a relatively young engine at this point, having only been introduced in 2018. As a result, not as many aftermarket manufacturers have developed high-pressure fuel pump upgrades for the Gen 2 B58 yet. As of right now, Spool Performance is the only company that has released an upgraded HPFP upgrade for the B58TU, but seeing as how the Mark 5 Supra is one of the most popular tuner cars on the market right now, more B58TU high-pressure fuel pump upgrade options will likely be available soon.
Gen 1 B58 (Pre-TU) HPFP Upgrade Options
BMW B58TU HPFP
2) HDP6: 350bar ~57% flow over stock
Price: $449
Tuning: Plug and Play
Compatibility: F chassis B58 compatible.
While we just said that the fuel pump options for the Gen 1 and Gen 2 B58s are different, there is an exception to that rule. The factory B58TU high pressure fuel pump is actually compatible with the Gen 1 B58 and provides around 57% more flow than the Gen 1 pump. As a result, it is a solid option for those looking to get more power out of their stock turbo or even an upgraded turbo to a point.
Another serious benefit of the B58TU HPFP is its price. With most suppliers selling the Gen 2 pump for around $450-$500, it is undoubtedly the least expensive pump option on this list while retaining OEM quality. The Gen 2 HPFP is the most common pump option for Gen 1 B58 owners due to these benefits, with most owners reporting great results.
As an added benefit, the B58TU pump is the only B58 HPFP upgrade option that works on the stock tune. That makes it the easiest option if you aren’t keen on messing around with additional tuning and want to take advantage of the extra flow that it provides out of the box.
DORCH Engineering:
1) DS15: ~40% over stock
2) DS25-250: ~68% over stock
Price: $1,199 – $1,799
Compatible: F Chassis + Gen 1 G Chassis B58 compatible
Tuning: BM3 and MHD supported
Dorsch pumps are another very popular option for the B58 and provide some pretty impressive flow figures. Like many of the other manufacturers on this list, Dorch offers two different pumps with different flow capabilities. Dorch’s entry level DS15 pump provides a 40% flow increase over stock, supporting power levels of 600whp on pump gas and 440whp on full E85. Their DS25-250 model is a significant step up from the DS15, rated for a 68% flow increase over stock, allowing for 750whp on pump gas and 550whp on full E85. Their fuel pumps are plug-and-play on the B58 and are supported by both BM3 and MHD.
XDI:
1) XDI-35: 200bar ~36% flow over stock
2) XDI-60: 260bar ~63% flow over stock
Price: $1,750 – $2,499
Tuning: Custom tuning required
Compatibility: F chassis B58 compatible.
While XDI stage 1 and stage 2 HPFPs increase flow by a substantial amount over the factory fuel pump, it is hard to justify the price of both pumps when the competition outflows both XDI options at a significantly lower price. With that being said, both pumps can support a significant amount more power when running an upgraded turbocharger or a higher-content ethanol blend.
Spool Performance:
1) FX-170: ~50% flow over stock
2) FX-200: ~100% over stock
Price: $1,399-$1,799
Tuning: Supported by BM3 and MHD
Compatible: F series B58 compatible
These are significantly cheaper than XDI while also flowing significantly more as well. Both Spool options are plug-and-play with the B58 and do not require any cutting or splicing in order for them to work. Spool pumps are supported by most major tuners including JB4, MHD, and BM3.
The Spool Performance FX-200 is one of the highest-flowing B58 HPFP options on the market, providing a 100% flow increase over the stock pump. As a result, it is the best pump if you are aiming at massive horsepower goals from an upgraded turbo with heavy support from ethanol.
B58TU (Gen 2) High Pressure Fuel Pump Options
At this point in time, the B58TU is still a relatively young engine, and high pressure fuel pump manufacturers are still in the process of developing higher performance options for the Gen 2 B58. As a result, there are far fewer HPFP upgrade options available for the Gen 2. In fact, Spool Performance is the only company with an upgraded HPFP offering for the B58TU. With that being said, the Spool pump is extremely capable and should satisfy the needs of any B58TU owner hunting for more power.
Spool Performance
1) FX350 (Gen 2)
Price: $2,299
Tuning: Supported by BM3 and MHD
Compatible: G Chassis (Gen 2) B58 compatible
As with the Spool pumps that we have already discussed, the FX350 is guaranteed to be quality based on Spool’s reputation. In essence, the FX350 is simply the Gen 1 B58 FX200 designed to work with the Gen 2 B58’s 350bar fuel system. As a result, it has similar flow benefits to the FX200. Spool states that the FX350 has the flow capabilities to support 800whp on pump gas, 670whp on an E50 mix, and 600whp on full E85.
BMW B58 High Pressure Fuel Pump Upgrade Summary
If you are planning on making big power from a BMW B58 engine, fueling modifications are a necessity. While the B58’s stock high pressure fuel pump is certainly capable, it still taps out rather early considering how easy it is to make extreme amounts of power from the 3.0L inline-6.
The Gen 1 B58’s HPFP hits a wall at around the 450whp mark on pump gas and 420whp when running an ethanol blend. While the Gen 2 B58’s HPFP is much more capable, with limits close to 100 horsepower more than the Gen 1 pump, those looking to push beyond the 600whp mark with their B58-powered BMW or Supra will also need to think about upgrading as well.
While there are a couple of ways to provide the necessary amount of fueling to carry a B58 into stage 2 and stage 3 territory, a high pressure fuel pump is the easiest, safest, and most straightforward way of doing that. While a port injection system certainly has its benefits for extremely high horsepower builds, it also comes with the added headache of installing an array of auxiliary parts and dealing with the complications of tuning it. A high pressure fuel pump eliminates all of that hassle.
At this point in time, there are a number of very quality B58 high pressure fuel pumps available that have been extensively user tested by the community. While none of the above pumps are a bad choice, DORCH and Spool are by far the most reputable suppliers in the community and have shown great results on hundreds of high-horsepower B58s.
