The B58 is the successor to the N54 and N55 engines, both of which were highly tune-able and able to make lots of horsepower with only a handful of supporting mods. The N54 takes the cake in regards to horsepower capabilities, but it had many engine problems as a result. The N55 platform was made more restrictive from a tuning perspective in order to improve engine reliability, which worked well.
While still a relatiely new engine, we’ve certainly seen a massive boom in the B58 aftermarket seen in the past couple of years. In that time, it has proven itself to be one of the most reliable and bulletproof turbocharged engines that BMW has ever made, and it lends itself very well to aftermarket perfromance. Using the same general bolt-on recipe that produced big power on the N54 and N55 engines before it, the B58 is capable of making 500hp, with 450 or so to the wheels with only a handful of supporting mods.
Pre-Tuning Must Do’s: Spark Plugs and Ignition Coils
The B58 has pretty good ignition from the factory, but unless your plugs and coils are less than 20,000 miles old, we recommend replacing them. To create more horsepower, the car needs to pump more gas into the engine to create the additional combustion. Old spark plugs get worn down and become less effective, resulting in extra gas being left in the combustion chamber which can then pre-detonate and cause misfires.
If you are simply running a JB4 tune and other bolt-on mods then we suggest replacing the spark plugs with OEM plugs. If you are planning on upgrading your turbos, then we recommend using the 1-step colder option. Always stick to the OEM ignition coils.
- OEM B58 Spark Plugs: for all tuned and FBO cars running stock turbos
- 1-Step Colder Spark Plugs: for all B58’s with upgraded turbos, note these are the same 1-step colder plugs used by the N55
- OEM B58 Ignition Coils: use these coils regardless of the spark plug you are using
500HP B58 Mod List
At this point, there is a pretty established 500 horsepower formula for the BMW B58 engine. As we said earlier, to breach the 500 horsepower barrier, you won’t need upgraded turbos, extensive internal work, or a massive fortune to spend on it all.
All of the modifications on this list haven’t changed much since the N54 and N55, as most turbocharged BMW engines benefit the most from a few tried and true upgrades. The following bolt-on mods will get you close to, if not over, the 500 horsepower/450 wheel horsepower mark on the BMW B58 engine.
- BMS B58 Performance Intake
- BMS JB4 Piggyback Tune / bootmod3 Flash Tune
- VRSF Catless Downpipes
- B58 Water Methanol Injection
If you would rather consume this content via a video, check out our How to Build a 500WHP B58 video below:
1. BMS B58 Performance Air Intake
An upgraded intake allows your car to bring more air into the engine which creates more horsepower, faster turbo spool, and an awesome sound. The extra airflow is crucial for creating more pressure inside the engine and also maximizing horsepower gains from additional mods. We consider this a necessity if you are going to use a tuner such as the JB4 or bootmod3 on your B58. The sound made by the intake makes it worth it by itself.
There are a handful of manufacturers out there and all intake systems are more or less the same. We recommend BMS because they have a fantastic reputation in the BMW community and are affordable and quality.
Read our full-guide on intakes here: BMW B58 Upgraded Performance Intake Guide
Price: $199 + Shipping
Horsepower/Torque Gains: 10-20whp / 15-20tq
Burger Motorsports B58 Performance Intake
BMS makes our favorite intake on the market – in addition to all the performance benefits it is also rather affordable, making it our favorite and recommended intake for the B58.
2. B58 Tune
A quality tune for the BMW B58 is undoubtedly the most cost-effective way to squeeze some additional power from the 3.0L inline-6. The B58’s tuning history is interesting, as tuning companies didn’t find a DME unlock solution until two years after the engine’s debut. Before that time, B58 piggyback tuners ruled the space. However, after the DME was able to be unlocked, flash tunes began to take the top spot.
Both piggyback and flash tunes have their pros and cons. Piggyback tunes do not alter factory DME parameters but instead tricks the DME into running more aggressive ignition timing, increasing boost and other power-increasing parameters. They also allow for on-the-fly map changes, they are easy to install and use, and are less likely to be detected by dealers and service centers if reset to stock. However, piggyback tunes don’t allow for the precise parameter changes possible with a flash tune.
B58 flash tunes, on the other hand, do make adjustments to DME parameters. Flash tunes are generated on computers and the software is then loaded to the cars computer, the DME, generally through the OBDII port. Modern flash tunes, like those by MHD and BM3, are easy to install over a wireless device. Ultimately, they allow for more precise tuning and are not limited to factory DME presets.
If you are interested in learning more, take a look at our Flash Tunes vs Piggyback Tunes guide, but for now we’ll cover our favorite options for each.
BMS JB4 Piggyback Tuner
Burger Motorsports JB4 tuner is the most popular tuner used on both the N54 and N55 platforms, which is why we recommend it for the B58 platform. This is a piggyback tuner, verses a flash tuner. That means that the JB4 doesn’t actually alter any DME parameters but instead alters signals and sensors to accomplish the tune’s goal. That is in contrast to a B58 flash tune which requires the ECU to be overwritten and it wasn’t until late 2018 that tuning companies were able to crack into the DME and ECU.
While most B58 enthusiasts have moved more towards flash tunes in the recent years, piggyback tunes still have their benefits. Since piggyback tuners, like the JB4, don’t alter the actual DME parameters, the tune can be removed with no trace if you are under factory warranty and need to take your BMW to a certified repair center. We don’t reccomend tuning your B58 BMW under factory warranty as there are other ways that a dealer can detect a tune, but a B58 piggyback tune will give you the best chance of flying under the radar.
The performance gains from a B58 JB4 tune are hard to argue with. With no additional modficaitons, the JB4 is capable of unlocking up to 80 whp on the B58. For a little over $500, it’s hard to argue with that.
Horsepower/Torque Gains: 60-80whp / 40-60tq
Burger Motorsports JB4 BMW B58
Burger Motorsports’ JB4 is hands down our favorite piggyback tuner for the BMW B58. The JB4 has been the go-to piggyback tuner since the N54 and we still love it today.
BM3 Bootmod3 B58 Flash Tune
Over the past few years, the bootmod3 B58 flash tune has become the most popular option on the market by a significant margin. A lot of that boils down to the fact that BM3 has an extremely easy to use interface, fantastic customer support, and has the potential to generate the most amount of additional performance.
As we mentioned earlier, the versatility and customizability of a B58 flash tune are unmatched. Compared to a piggyback, the DME will see and register all of the changes made to fueling, timing, boost, VANOS, and other tables, which is seen to be a safer approach than tricking it in some instances. Regardless, the additional customizability means that you’ll have the ability to tune your B58 to the exact perameters that you’re looking for whether it be minor adjustments to fueling tables or limiting torque through a part of the rev range.
As a side note, there are a couple of very solid B58 flash tune options on the market currently, with MHD coming in a close second to BM3 in terms of support and ease of use. Ultimately, they are neary identical in terms of function and how much performance can be extracted using them. It boils down to personal preference. If you want to learn more about either BM3 or MHD flash tuning, we have written dedicated guides about them for the B58.
Read our full guide on BM3 flash tunes here: BMW B58 BM3 Tuning Guide
Read our full guide on MHD flash tunes here: BMW B58 MHD Tuning Guide
Stage 1 91 octane: up to 18% HP / 26% TQ
Stage 1 93 octane: up to 20% HP / 26% TQ
Stage 2 91 octane: up to 24% HP / 32% TQ
Stage 2 93 octane: up to 26% HP / 32% TQ
bootmod3 BMW B58 Flash Tune
While there are numerous fantastic flash tune options available for the B58, BM3 takes the top spot in our book followed closely by MHD.
3. Catless Downpipes – VRSF
With an intake and tune, your B58 will be bringing significantly more air into the engine. Which means, now we need to be able to get all of that air out. If the air can’t leave as fast as it comes in, back pressure is created. The factory downpipe has a catalytic converter on it, which for emissions purposes, is very restrictive. By replacing the restrictive OEM downpipes with catless downpipes, we eliminate a significant amount of the back pressure and create more horsepower and boost.
I would note a few things here. First, just replacing your downpipes will not make your car crazy loud. It will make a slightly deeper tone, but its not very noticeable from the front of the car and definitely not noticeable inside of it. Your wife won’t even know you did anything to it! Secondly, we only recommend a full exhaust system if you really care about the sound of the car. A full exhaust system will run you more than this list of mods and will get you probably 5 additional horsepower. Full systems aren’t worth it unless you want the loud noise.
VRSF is the best balance of price and performance. Zach and I run the VRSF downpipes on our N54’s and they are great. For our European readers, we recommend the Masata Catless Downpipe which offers the same performance benefits as the VRSF option which is difficult to find overseas.
Read our full guide on downpipes here: BMW B58 Upgraded Downpipe Guide
We strongly recommend catless, but high-flow catted is still better than stock if you are concerned about emissions testing.
Horsepower Gains: 25-30whp with the JB4 + faster turbo spool
4. Meth Injection
Meth injection is the key to making 500hp at the crank and 450whp. Meth injection, referred to as WMI (water/meth injection), sprays a mixture of water and methanol into the intake air just prior to it entering the combustion chamber. The spray reduces the air temperature and also boosts the octane of the gas entering the combustion chamber. Overall result is more combustion aka more power. On the N54 and N55, a chargepipe with a meth bung would be needed, but the chargepipe on the B58 is a pain to remove, so BMS built and adapter which mounts up to the throttle body.
A big limitation of the B58 is fueling. The only way to get around this limitation is through the addition of meth injection. With the above mods, but no meth, you will probably push approx. 400-415whp on 93 octane pump gas. Meth will get you to the 450whp mark.
Price: Depends but approx. $500
Read our full guide on Water/Methanol Injection here: BMW B58 Water Methanol Guide
We recommend running the BMS kit which you can find all about here: B58 BMS Meth Injection Kit
What about Intercooler (FMIC) Upgrades?
If you were reading through our N54 or N55 mod list, you would find an upgraded intercooler on the list. Intercoolers cool the air prior to it entering the engine, which increases the oxygen content of the air ultimately resulting in more combustion and power. The stock B58 intercooler is definitely good, and better than the N55 and N54 ones, largely due to its air to water cooled design.
The factory intercooler is a part of its own low temp cooling system, seperate from the engine cooling circuit. This allows it to have better efficiency, as the incoming air isn’t effected by warm enigne coolant. The one issue, when it comes to aftermarket intercooler upgrades, is that the air to water intercooler is intergrated into the intake manifold. For that reason, there aren’t any upgraded intercoolers available for the B58 as that would require a new manifold as well.
While there isn’t an explicit upgrade available for the intercooler itself, there are a few upgraded heat exchangers available. Both Burger Motorsports and CSF offer upgraded B58 heat exchangers that have a larger surface area which helps increase the efficeincy of the intercooler itself.
If you want to learn more about intercooler upgrades, take a look at out BMW B58 Intercooler & Heat Exchanger Upgrade Guide.
500 Horsepower BMW B58 FAQ
What are the best modifications for the BMW B58?
If you are shooting for the 500 horsepower/450 wheel horsepower threshold, you’ll need a few bolt-on mdifications including an upgraded intake, a tune, an upgraded high-flow or catless downpipe, and water/methanol injection. If you want to push your engine beyond that, you’ll have to start considering an upgraded turbo and additional fueling modifications.
How much power can a BMW B58 handle?
With stock internals, the BMW B58 can handle somewhere in the ballpark of 600-650whp and 550-600wtq. That isn’t really a concern with the modificaitons that we’ve listed here.