N54 MHD Guide

BMW N54 MHD Flash Tunes Horsepower Gains

About Zach Mayock - DieselIQ

Meet Zach

Zach is a BMW enthusiast with a passion for performance. With over 10 years of experience modifying and performing DIY work on BMWs, he’s developed a deep understanding of virtually every BMW engine. He’s also the proud owner of a 600whp N54 with upgraded twin turbos and an E30 325i drift car and has a particular affinity for the S58 engine. Zach is highly knowledgeable about all things BMW, but his expertise in tuning and performance mods sets him apart. His experience as an enthusiast, combined with his technical knowledge, makes him an essential resource for anyone looking to improve the performance of their BMW.

In our general MHD post we discussed some of the basics of the MHD tuning app and installation. This post will cover the various BMW N54 flash maps along with supporting mods and expected horsepower on each map. To note – this post is based on the V8.1 maps available for the N54.

For more general information about the BMW N54 engine, take a look at our Ultimate BMW N54 Engine Guide which covers specs, reliability, common modifications, and more.

BMW N54 MHD Flash Tunes Horsepower Gains Contents:

N54 MHD Flash Tunes

You can skip to the next section if you’re familiar with MHD flash tunes for the N54 and simply want to know the recommended supporting mods and horsepower. As a quick background, MHD offers OTS (off-the-shelf) flash tunes for the N54. Flash tunes essentially re-write the ECU/DME to target more aggressive boost. Flashing the DME also gives the tune full control over fueling, ignition timing, AFRs, etc. This is a major benefit of flash tunes as opposed to piggyback tunes, such as the JB4.

Piggyback tunes act as advanced boost controllers, but “trick” the DME. They do not have full control like flash tunes do. Piggyback tunes simply run higher than stock boost and allow the factory DME tune to make the necessary adjustments. Some people will knock piggyback tunes for this fact, which we do not intend to do. As such, it is important to note we run JB4 piggyback tunes on our N54s and highly recommend this setup to others. However, piggyback tunes have their limits. At some point, the factory tune with a piggyback simply cannot keep up with things like fuel flow.

Enter flash tunes, and MHD’s OTS flash options. MHD offers four “stages” for the N54 along with different maps, dependent upon fuel quality, within each stage. Their flash tunes are highly proven and have been the go-to for many in the N54 community.

JB4 + N54 MHD Back-end Flash (BEF)

We must diverge for another brief moment to discuss the setup we recommend above all else – stacking the JB4 piggyback tune with an MHD BEF. The JB4 is loaded with unique features that come with the tune at no extra cost. It allows for steering wheel controls to change maps on the fly within seconds. A great option for those who may want a modest DD tune with the ability to crank things into kill mode in a second. It allows for gauge hi-jacking to display boost, AFRs, ignition timing, etc on the fuel and/or oil temperature gauges.

Additionally, the JB4 allows data-logging capabilities without the need to purchase the $69 MHD data-logging feature. You can limit boost by gear for 1st, 2nd, and 3rd gears. These are just a few features worth mentioning. We’re not done yet.

Most importantly, the JB4 is loaded with excellent safety features. Set a boost safety limit; if boost exceeds target the JB4 instantly kicks back to stock boost. If AFRs go dangerously lean the JB4 may save your engine. Again, it kicks into the stock boost map. It does the same when fuel pressure or meth flow become dangerously low. These are safety features worth having that flash tunes simply do not have.

In summary, the JB4 when coupled with a back-end flash tune retains its advanced boost control, user-friendly features, and safety features. However, the N54 MHD flash tune is given full control of AFR’s, timing, fueling, etc. It really is the best of both worlds and the ultimate tuning setup for the N54. This is simply something to consider prior to opting for a standalone N54 MHD flash tune. Anyways, the post is about MHD so let’s get back on track.

N54 MHD Maps (“Stages”)

BMW N54 MHD Flash Tune

As mentioned above, MHD offers four different stages for the N54. Each stage has different supporting mod recommendations. As the stages increase, so do boost and horsepower (assuming all else is constant, such as fueling). The available stages include 1, 1+, 2, and 2+. Within each stage, there are different options depending on fueling. Throughout the remainder of the post, we will discuss the different stages, requirements, and expected horsepower.

*We highly recommend replacing spark plugs and ignition coils prior to flashing any MHD tunes. Modded N54s are best suited to 1-step colder spark plugs, however, OEM plugs should hold up under 400whp.

N54 1 & 2-Step Colder Spark Plugs

N54 Ignition Coils

OEM Spark Plugs

**ALL horsepower numbers are assuming the N54 is running the recommended mods for each stage. Additionally, power varies from car to car even with the same exact mods. This may come down to differences in dynos, temperature, altitude, engine health, etc. As such, the horsepower numbers we mention are simply rough estimates.

As the N54 MHD supporting modifications begin to add up in the higher stages, fueling modifications become increasingly important. That is especially the case when you start to near the 400 horsepower mark. Due to the increased internal temperatures, it is a good idea to switch to higher octane or cooler-burning fuel to decrease heat buildup. Methanol injection is a good solution to help keep N54 internal temps to a minimum, preventing detonation and keeping the engine safe.

If you are interested in learning more about BMW N54 fueling modifications, check out our BMW N54 Fueling Mods Guide.

N54 MHD Stage 1 Horsepower & Mods

Mods Recommended: DCI

Target Boost: 14-16psi, tapering to ~10psi at redline

MHD’s stage 1 flash tunes for the N54 are basic, entry-level tunes. These maps do not require any supporting mods, unless opting for the E50 maps which require an upgraded low-pressure fuel pump (LPFP). However, due to the increased airflow, we recommend upgrading to dual cone intakes (DCI). If not for the slight bump in power, this $80 mod is worth it for the looks and sound alone.

91 Octane/95 RON: 310-320whp

93 Octane/98 RON: 320-330whp

95 Octane/102 RON: 330-340whp

E30: 330-340whp

E50: 340-350whp

The expected N54 wheel horsepower on the N54 MHD stage 1 maps falls right in the ballpark of 310-350whp. Boost targets become more aggressive on better fuels. Expect a 14psi peak on lower-grade fuels and up to 16psi on E50. 91 octane is poor fuel and not recommended unless nothing better is available. As fuel quality increases, horsepower sees a bump as well. These stage 1 maps are not aggressive enough to the point E30 fuel has a huge benefit over 95+ octane fuels. However, N54 E50 should give a pretty nice bump in power.

N54 MHD Stage 1+ Horsepower & Mods

Mods Recommended: DCI + FMIC

Target Boost: 14-16.5psi, tapering to 10-12psi at redline

The stage 1+ tunes are slightly more aggressive, targeting boost a couple of PSI higher than stage 1. Due to the additional boost, it is recommended to upgrade your FMIC. You can get by on the stock FMIC, but the tune will pull timing as IATs get too high. An FMIC is a great mod to have, nonetheless. While peak horsepower on glory runs may not see a huge increase, upgraded FMICs help with consistency.

91 Octane/95 RON: 320-330whp

93 Octane/98 RON: 330-340whp

95 Octane/102 RON: 340-350whp

E30: 340-350whp

E50: 350-370whp

Compared to N54 MHD stage 1, the 1+ maps pick up a bit of extra horsepower due to the increased boost and addition of an upgraded intercooler. Expect your N54 MHD stage 1+ tune to put you in the ballpark of 320-370whp. As with any of the N54 stages, 91 octane will result in lower boost targets and horsepower. Higher octane fuels will provide a nice bump in power while E85 mixtures show the best results.

N54 MHD Stage 2 Horsepower & Mods

Mods Recommended: FBO (DCI + FMIC + Catless DP’s)

Target Boost: 15.5-17psi, tapering to ~12psi at redline

Stage 2 maps are not too much more aggressive than stage 1+ maps. Boost targets will likely increase slightly, but N54 catless downpipes will provide the biggest difference. The butt-dyno will definitely approve as DP’s will reduce turbo spool time. Excellent N54 mod that we recommend regardless of the map you choose. Additionally, as with the above stage 1+ tune, a FMIC is not absolutely required but recommended. IATs and heat soak, on the N54, become more concerning as we increase boost.

91 Octane/95 RON: 330-340whp

93 Octane/98 RON: 340-350whp

95 Octane/102 RON: 350-360whp

E30: 350-370whp

E50: 370-390whp

The expected horsepower for the N54 MHD on stage 2 maps is in the ballpark of 330-390whp. This is about where E85 mixtures are going to begin providing the big benefits. We’re starting to generate enough heat and boost to the point E85’s cooling and knock resistance become important. Expect boost targets around 15.5-16psi on pump fuels and up to 17psi on E50 mixes.

N54 MHD Stage 2+ Horsepower & Mods

Mods Recommended: FBO (DCI + FMIC + DP’s)

Target Boost: 16-18psi, tapering to about 13-14psi at redline

As with N54 MHD stage 2, we recommend going full bolt-on. These stage 2+ tunes are beginning to push toward the upper “safe” limits of stock N54 turbos. You may even consider upgrading turbo inlets and outlets to help with turbo longevity. They flow more air and assist in reducing WGDC, especially towards redline. You will likely need a custom MHD flash tune to reap the full benefits of upgraded inlets and outlets. Nonetheless, they will make the stock turbos job a bit easier thereby assisting in reliability and longevity.

91 Octane/95 RON: 350-360whp

93 Octane/98 RON: 360-370whp

95 Octane/102 RON: 370-380whp

E30: 390-410whp

E50: 400-430whp

Stage 2+ maps are the most aggressive OTS maps from MHD. Horsepower is going to max out in the 350-430whp range, depending greatly upon fueling. Stage 2+ with E50 fuel should push peak boost to 18psi. This is also about the max boost we recommend running through the N54 stock turbos with stock inlets and outlets. Pushing the N54 any further on stock turbos is going to require higher E85 mixtures and custom flash maps.

N54 MHD Custom Flash Maps

Recommended Mods: FBO + LPFP + Inlets & Outlets + Meth Injection

Target Boost: 18+psi

Custom flash maps will vary significantly depending upon the tuner you choose to work with. We assume most people considering custom flash options are looking to push beyond 18psi. In this case, you will definitely want to be running FBO with an upgraded LPFP to run E50+ mixtures. Inlets and outlets will also give massive benefits with large torque increases. Power will also see some benefits, but the torque gains will be most impressive.

93+ Octane: 380-410whp / 420-450wtq

E50: 420-460whp / 450-480 wtq

100% E85: 460-500whp / 500+ wtq

It’s tough to put any exact numbers on custom tunes. These numbers are pretty aggressive and assume your N54 is about maxed out on stock turbos. There are a few N54’s running ~420whp on 93 octane, but that’s best case on aggressive timing and absolutely maxing stock turbos. The same can be said for the E50 and full E85 numbers.

Again, we are assuming aggressive tunes running FBO + Inlets/outlets + Meth. While these numbers may look tempting, we do not advise pushing the stock turbos this far unless you have plans to upgrade in the near future. If you’re not in a position to upgrade your turbos, stick to OTS maps or a modest custom flash.

BMW N54 MHD Flash Tunes Summary

MHD offers an excellent selection of OTS flash tunes for BMW N54 engines. Expected horsepower ranges from 310whp, on stage 1 maps with poor fueling, up to 430whp on the stage 2+ E50 map. It is important to ensure you are running proper supporting mods, especially as you opt for more and more aggressive tunes.

For anyone new to the N54 platform, or tuning/modding in general, we recommend starting on a less aggressive tune. Those looking to push their N54’s stock turbos to the upper limits should opt for a custom flash tune. However, pushing much past 18-20psi becomes a risky endeavor. As such, these setups should be reserved for those willing or looking to upgrade their turbos in the near future.

As a final note, our favorite setup is the JB4 + MHD back-end flash maps. You must purchase the MHD flasher module for $99, which unlocks free BEF maps. The JB4 allows more aggressive boost targets without the need for a custom flash. With the MHD E85 back-end flash and the JB4 switched to map 7, you can target boost in excess of 20psi.

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  1. I would like info.in N55 tuning. I recently purchased a 2015 435i Drive coupe very low miles. I want to improve performance but stay within the.limitations if the stock equipment..

  2. As far as tuning the N54 goes I’ve never installed a tune . That being said I wanna Make sure I do everything right so I don’t damage the Ecu, can anyone help me out with explaining it step by step so I make sure install the stage 2+ for upgraded downpipes correctly.

    1. It’s quite easy, I’ll guide you through it.

      First you gotta have a compatible OBD to USB cable (you can find those on many reputable sites like Amazon), then you get an OTG cable that connects to your Android phone/tablet.
      Next thing is having a battery charger ready to hook up when flashing cause you run the risk of a dead battery and a ruined ECU if yoy don’t use a battery charger (they’re pretty inexpensive; you could also borrow one from a local indy shop).

      Finally, download MHD N54 on your Android device, connect it with the OBD plug, purchase an MHD license (for $99 iirc), purchase the OTS map (stage) you want to run on your n54.

      Make sure you battery charger is hooked up (and running at the appropriate voltage) to the jump-start prong under the hood (has a red cover with + sign), then confirm that your android device is connected perfectly and will remain stationary throughout the flashing (can’t risk interrupting the connection mid-flash), then save a backup of your stock map. (I believe the app will prompt you to do that anyway).

      After the backup, go into the flashing section, choose the correct fuel type that you’ll be running along with the transmission type and select the OTS map (stage).
      There are additional options in the flashing section before you proceed, where you can select all sorts of nice options e.g. burbles, linear throttle mapping, cold start noise reduction.

      ***MAKE SURE YOU HAVE THE IGNITION IN THE ON POSITION BEFORE FLASHING (Pressing the start/stop button once after inserting the key) then select Flash.

      The dashboard and iDrive will go haywire in the process showing all sorts of errors, don’t panic! That’s completely normal. This first flash ever will typically take anywhere between 10 and 30 mins depending on how powerful the Android device is.

      After the flashing is done, turn off the ignition for a minute then start the car with fingers crossed.

      Reverting back to stock map or switching between maps after the initial flash will take significantly less time (1-3 mins). Therefore, it’s relatively safe to reflash/switch maps or options without the battery charger.

      Enjoy the new beast that you’ll be unleashing. Best of luck!

  3. I just discovered this site yesterday and I’m really impressed by how well written, information-packed and straight to the point the articles are. Big thanks to everyone contributing to this! Cheers!

  4. Hi i have MHD with the jb4 backened app , but i do not have JB4 software on my car . Can i still use the jb4 maps using the backened app without JB4 . Thank You

  5. My 535XI E61 N54 6-spd manual wagon (total unicorn…love the long roof) is in the shop for scheduled service and tires. Talking to techs (the shop is run by BMW enthusiasts/racing specialists) about tuning and other upgrades.

    Currently the vehicle is all stock. Turbos are still in good condition so not going to upgrade them….yet.

    Here’s what I’m hearing from the shop:

    OEM intercoolers are bigger in 535 than 335, so he only recommended upgrade if going with bigger turbos.

    Chargepipe is OK and not recommending replacement unless I move to bigger turbos or very aggressive tune to push the stock turbos to limit. Downside to aggressive tune on stock turbos is they are already old and pushing them now could be the end for them.

    DCI’s not needed unless going with bigger turbos. They draw hot engine air anyways so there isn’t much if any hp gain without upgraded turbos.

    Exhaust mods not worth it for similar reason that DCI’s are not needed. The stock turbos are the bottleneck. Also they don’t do catless systems, and don’t recommend them either because of legality. I haven’t asked their opinion on catted downpipes.

    For a simple tune with no other mods they recommend Dinan Stage 2 at cost of $500 for about 75 hp gain. They recommend MHD over JB4 instead if wanting lots of options. I think it’s a matter of personal philosophy about using flashes over piggyback tuners. It’s interesting that you recommend both JB4 and MHD back-end flash.

    I supposed I could get them to do the Dinan Stage 2 (so I don’t have to mess with it) and when the turbos need replacing (eventually) I can just worry about more versatile tuning options later (i.e. JB4 w/ MHD).

    1. Hi Keith,

      No offense to Dinan, but we would never opt for their tunes. Dinan offers the unique benefit of remaining under factory warranty. Outside of warranty there really isn’t much reason to go with Dinan, in our opinion. There usually isn’t anything that requires “messing with” when it comes to the JB4 or MHD tunes. The JB4 is a simple plug and play tune – plug it into the DME then select a map and go. MHD tunes simply need to be flashed and go. As with any tunes – they may expose existing weaknesses with the car. So you might be messing with things in that case but the same could be said for Dinan. If the shop is a Dinan dealer then they may have incentive to recommend Dinan tunes. We make no money from recommending JB4 or MHD tunes. We honestly believe MHD and JB4 are two of the best off-the-shelf tuning options for the N54.

      Interesting recommendations from the shop. There is definitely a difference between requirements and recommendations. Sure, you can throw 17 psi at the N54 stock turbos without any other modifications. Would we recommend that? No. An FMIC is one of the best consistency mods and there isn’t much debate about the importance of cooler IAT’s. Not only does it help prevent heat soak and pulled timing/boost, but it also acts as a means of knock suppression. Catless downpipes offer massive performance benefits and make the turbochargers job easier. A high-flow catted DP also offers improvements, but to a lesser extent.

      As for intakes, gains are definitely minimal on modest tunes. However, there still are benefits on stock turbos and once you hear the sound it will be hard to ever turn back. Regarding the hot air – that’s been discussed, tested, and proven that open intakes do not lead to a significant difference in actual IAT’s. The engine bay receives adequate fresh air flow and the air travels through incredibly hot turbos before being cooled by the FMIC. Slightly warmer temperatures at the filters does not always correspond to an increase in IAT’s since that air is cooled by the FMIC anyways.

      Just our .02. If you want a modest tune and have no other plans for the car then there isn’t anything wrong with Dinan. If you want to push 16-18+ psi then we would highly recommend intakes, DPs, and FMIC upgrades along with either the JB4 or MHD flash tune. Each to their own, but we’re big believers in doing things right the first time around.

      Best Regards,

  6. Just to chime in on the DCI Ait
    There’s no intake air temp difference running the dual open dci on my car, and second note to be taken is there is a significant increase in the flow restriction when going over 15-18psi on the stock air box, just to add my car has the BMS cowl filters and I believe this also aids in the air flow under the bonnet.
    So the “maybe” 2-3 deg Lower ait’s considering the standard cowl filter and water tray in place are totally out weighed by the air flow restriction on the stock air box

    N54 life

    1. Hi Eric,

      We absolutely agree. The “hot air intake” myth has been debunked many times. IAT differences are minimal since the air pulled thru the intakes is rapidly heated by the turbos and subsequently cooled by the FMIC. The air entering the intakes is a bit hotter but that’s negated as the air travels thru much hotter turbos before being cooled by the FMIC.

      The stock airbox does hold up OK to about 15-16psi, but much above that and the DCI’s definitely help with air flow.

      Best Regards,

    1. Hi Ronnie,

      As far as I am aware MHD only offers tune for a few of the newer turbo BMW’s – N54, N55, N20, S55, etc. Your 745Li is powered by the N62 engine, which we’re not quite as familiar with in regards to tuning. It’s a slightly different ball game when it comes to turbo vs NA engines.

      There’s surely a few options out there for tunes for the N62 engine. However, I don’t know which N62 tunes are great choices. Beside that fact – on a NA engine you’re probably looking at power gains of 5-10whp. With a 300+ horsepower engine that’s not going to make a huge difference in feel or performance. NA engines are great in many regards but when it comes to tuning and aftermarket potential it’s not quite as high (at least without adding forced induction).

      Best Regards,

  7. Great stuff! I have a 2009 e93 335i I purchased last year and I did so specifically for the N54. I wanted a fun car to daily in good weather and put away in the winter. 1st mod was the DCI’s, 2nd was the Wagner 5in stepped IC and I went with the ARM charge pipe with a TIAL bov (I believe that’s a MUST and shouldn’t be listed as optional). Then I tuned it with MHD and started with stage 1+. I immediately got misfires on the sjake down run and already had NGK 1 step colder plugs with Delphi coils on the way. Installed those a few days later and I was amazed at how the car performed. Last week I installed a set of ARM catless downpipes and turned it up to stage 2+. The car is an animal right now. I was thinking of doing the inlets and messing with some e85 but I’d like to keep the stock turbos for as long as I can. I might just do the XHP tranny flash and call it a day.

  8. This is probably a dumb question and should be able to find it. When flashing, whether Wifi or OBD cable, what setting should I put my CTEK battery charger? I’ve heard of maintenance mode and then I’ve heard of charging mode. Seems a bit mixed but want to get it right the first since I plan on flash MHD and XHP by this summer. Thanks in advance!

  9. Hi, I own a 2008 X6 with the N54 engine. I have had issues with the MHD tune in erratic performance. I took the car to a dyno tuning specialist and he wanted me to send some data logs to MHD, as he believed that the tune needed custom work for my vehicle but no response. I have replaced the plugs, coils, injectors, MAF sensor, vanos solenoids, new performance aluminium charge pipe, turbo smart blow off valves and upgraded intercooler and still it has issues. Any suggestions? I owned a 335i coupe and had no issues with the MHD but had installed a performance intercooler, catless downpipes and BMS air intake duel filters on a new charge pipe.

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