N55 JB4 MHD Backend Map - Help Please

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GeoffCollins
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N55 JB4 MHD Backend Map - Help Please

Post by GeoffCollins » Thu May 10, 2018 10:03 am

I've been looking everywhere and can't find a definitive answer to my question, I understand that by running the JB4 with MHD Backend is a safer option as the JB4 has better safety features, and that the JB4 will retain the dash controls, but what is the purpose of the MHD backend?

Nowhere says that I will gain more power, or if I will be able to adjust the exhaust burble, turn of cold start and all the good features of the MHD, and once the MHD backend is installed, will i be able to install the MHD Stage 2+ map? If so how will the map controls on the JB4 work with the MHD maps?

Sorry for all the questions, and thank you in advance for anyone who can shed some light!
M135i (2014 Manual) - Custom Stainless Exhaust, JB4, BMS Intake, M4 LCA, Eibach Pro's, Cades Bern Wheels, Reiger Diffuser, Maxton Splitter, Double Slat Grills, M4 Mirror Caps

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Re: N55 JB4 MHD Backend Map - Help Please

Post by Blind Pugh » Thu May 10, 2018 10:27 am

GC,

Have you read this ?

http://www.n54tech.com/forums/showthread.php?t=51166
What benefits does a back end flash map add to the JB4?

Adding in the back end flash map allows JB4 adjustment over a wider range of engine parameters than are available on the factory flash. Including direct adjustment of timing and fueling tables, VANOS adjustment, fuel scalar adjustment for heavier E85 mixtures than possible JB4 only, speed limiter delete, optional exhaust burble, higher calculated torque reported to the automatic transmission, and a host of other parameters than are only possible via flashing the DME.

What are the benefits of running a JB4 with a flash rather than flash only for tuning?

While it's possible to tune an F series without a JB4 doing so comes with many disadvantages.

1) With JB4s unique features and logic paths, combined with the flexibility of adjusting DME tables directly via the back end flash map, you get better quality, safety, and more powerful tuning. The JB4 includes more robust safety systems than are possible via flash only. Starting with fundamental safety systems like reverting to a safety map if boost exceeds your safety setting, if the air/fuel ratio in either bank turns dangerously lean, or if fuel pressure drops below a safe level. While you might think the DME alone can handle these basic safety systems surprisingly it's not the case. The DME will happily let you run along at full power and a 18:1 AFR, with boost pegged, and the only fuel pressure safety provided is when fuel pressure drops down so low fuel injection itself has to be suspended.

2) More mapping options including absolute boost target maps. The JB4 boost control system is programmed to offer both absolute and additive maps. Absolute meaning you'll always target a specific boost level. Unlike the DME which naturally implements a LOAD control system where boost levels go down when it's cold and go up when its warm. The opposite of what you generally want for turbocharged performance. In addition the JB4 is quick and easily adaptable to a wide range of setups eliminating the need for expensive custom boost tuning and the risks that come with repeated logs on systems that are not yet setup. It's not uncommon for engine damage to occur while a new setup is initially being dialed in. The JB4 automatically tunes wastegate dutycycle, fuel trims, and other important tuning criteria full time in the background greatly simplifying the tuning process. In addition the JB4 auto-tuning map can self tune for various ethanol mixtures without the need of an expensive and difficult to install flex fuel sensor. Pedal to boost mapping, spool aggression, boost by gear, and other critical factors can be easily adjusted to suit the needs for the particular track or racing situation.

3) On the fly changes. Whether it's changing the boost/power level, boost by gear setting (including being able to disable it on the fly for burn outs or if traction turns out to be better than expected), pedal input, exhaust flap position, or what gauges are shown in dash, the JB4 allows a wide range of user adjustment real time from the drivers seat without having to use a 3rd party device or risk programming the DME between runs. You're able to make the changes while out on the track where you need to make them.

4) The JB4 allows for much better real time feedback to the driver. User adjustable in dash gauges allow you to keep a constant eye on boost, timing, knock, meth flow, and/or AFR, all selectable and changeable on the fly from the drivers seat. A user adjustable shift light can be triggered making rowing through the gears easier. JB4 Mobile allows wireless bluetooth logging via your Android or Apple phone without a cable locked in your OBDII port. In addition you can select map0 on the fly to allow OBDII port logging and diagnostics when needed for vehicle service. The JB4 default logging set includes all relevant data required for tuning including boost, timing cylinders 1-6, AFR and fuel trims in both banks, high and low fuel pressure, load, calculated torque, trans temperature, and many other parameters. The JB4 provides a simple to use but incredibly robust data logging system eliminating the need to select what parameters to record before each run and providing instant on the fly charting without the need of 3rd party internet programs. We routinely add parameters to the JB4 logging set based on customer feedback and evolving tuning requirements.

5) Integrated JB4 features such as anti-lag, port injection control, flex fuel sensor, and progressive water/meth (WMI) control eliminate the need for independent add on boxes that are more difficult to install and technically unable to communicate with each other. Integration allows these extra features to share information for a smooth and cohesive tuning solution. When the DME requests a torque drop due to traction or stability control the JB4, WMI, and PI systems all respond accordingly. WMI integration is able to hold boost levels low UNTIL fluid is flowing adequately to prevent spool up and transitional knock, adjust your boost target if the fluid being injected turns out not to be as potent as was expected or required to prevent knock, and in the event of a fail-safe depending on the severity of the situation either lower your boost target partially OR instantly dump boost out the diverter/close the throttle/cut timing. These are just some of the many examples of why having add on boxes an features all integrated through a single system is advantageous.

6) Does not require a MAP sensor change for higher boost levels. On S55 models the JB4 can control up to 36psi with both factory sensors, and on N55 models can control up to 21psi with both factory sensors, and 36psi by replacing the TMAP sensor only with a 3.5bar. In addition to saving money on a 3.5bar MAP sensor on the S55 in particular it reduces headaches having to switch the hard to reach MAP sensor back to stock when flashing to stock.

7) Free maps for life. The JB4 is widely used and widely supported including free unlocked back end flash maps and custom mapping support from BMS via the n54tech support forum. BMS sponsors and attends several 1/4 mile and 1/2 mile races per year continuously improving the JB4 base maps and features based on real world experience and feedback. These updates are provided free of charge to JB4 customers via n54tech firmware posts.

8) The JB4 hardware is robust, reliable, highly developed, and upgradable, with many thousands of systems in use since 2008 when it was first released. The key to the JB4’s success is that it DOES NOT replace the factory engine computer or DME. The JB4 simply adds on to functionality already provided by the DME. As a result the DME remains in full control of your engine at all times with the JB4 dynamically making small but impactful adjustments to add in extra safety systems and features and dramatically improve performance. And unlike disposable flash maps the JB4 is a physical system you can remove and resell down the road
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Re: N55 JB4 MHD Backend Map - Help Please

Post by GeoffCollins » Thu May 10, 2018 10:36 am

Blind Pugh wrote:
Thu May 10, 2018 10:27 am
I did but it doesn't mention how the maps work, does it keep the same sort of power as the JB4 produces just safer?

And do I get the adjustability of the MHD map and JB4 maps combined?

EDIT: Ignore me it mentions it at the bottom
M135i (2014 Manual) - Custom Stainless Exhaust, JB4, BMS Intake, M4 LCA, Eibach Pro's, Cades Bern Wheels, Reiger Diffuser, Maxton Splitter, Double Slat Grills, M4 Mirror Caps

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Re: N55 JB4 MHD Backend Map - Help Please

Post by mick.86uk » Sun May 13, 2018 4:43 pm

GeoffCollins wrote:
Thu May 10, 2018 10:03 am
I've been looking everywhere and can't find a definitive answer to my question, I understand that by running the JB4 with MHD Backend is a safer option as the JB4 has better safety features, and that the JB4 will retain the dash controls, but what is the purpose of the MHD backend?

Nowhere says that I will gain more power, or if I will be able to adjust the exhaust burble, turn of cold start and all the good features of the MHD, and once the MHD backend is installed, will i be able to install the MHD Stage 2+ map? If so how will the map controls on the JB4 work with the MHD maps?

Sorry for all the questions, and thank you in advance for anyone who can shed some light!
Did you get the backend flash done?

I'm looking at getting the JB4 BEF race map flashed tomorrow, just waiting on the android tablet to be delivered so I can load the MHD flasher.
2014 F20 M135i - Manual - Glacier Silver - Pro Nav - HK Audio - Drexler LSD - JB4 - BCS Cat - BCS Powervalve - M4 LCAs - Bilstein B14s - aFe Drop In & Scoop
Gone:
2009 E92 335i M Sport
2004 E46 M3
2005 E87 130i M Sport

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Re: N55 JB4 MHD Backend Map - Help Please

Post by GeoffCollins » Mon May 14, 2018 9:36 am

mick.86uk wrote:
Sun May 13, 2018 4:43 pm
Did you get the backend flash done?

I'm looking at getting the JB4 BEF race map flashed tomorrow, just waiting on the android tablet to be delivered so I can load the MHD flasher.
I haven't yet, I've got all the cables and tablet etc but just haven't had time this weekend!
M135i (2014 Manual) - Custom Stainless Exhaust, JB4, BMS Intake, M4 LCA, Eibach Pro's, Cades Bern Wheels, Reiger Diffuser, Maxton Splitter, Double Slat Grills, M4 Mirror Caps

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Re: N55 JB4 MHD Backend Map - Help Please

Post by mick.86uk » Tue May 22, 2018 9:06 pm

GeoffCollins wrote:
Mon May 14, 2018 9:36 am
mick.86uk wrote:
Sun May 13, 2018 4:43 pm
Did you get the backend flash done?

I'm looking at getting the JB4 BEF race map flashed tomorrow, just waiting on the android tablet to be delivered so I can load the MHD flasher.
I haven't yet, I've got all the cables and tablet etc but just haven't had time this weekend!
I've flashed mine today!

Impressed with the JB4 BEF maps compared to the standard JB4 maps.

Now feels super smooth and progressive right through the rev range, need to time some 100-200kph on the vbox but feels quicker now.

The cold start noise reduction option has cured my loud rattling BCS exhaust, no longer embarrassing to start it up from cold. :thumbs:
2014 F20 M135i - Manual - Glacier Silver - Pro Nav - HK Audio - Drexler LSD - JB4 - BCS Cat - BCS Powervalve - M4 LCAs - Bilstein B14s - aFe Drop In & Scoop
Gone:
2009 E92 335i M Sport
2004 E46 M3
2005 E87 130i M Sport

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GeoffCollins
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Re: N55 JB4 MHD Backend Map - Help Please

Post by GeoffCollins » Wed May 23, 2018 10:32 am

mick.86uk wrote:
Tue May 22, 2018 9:06 pm
GeoffCollins wrote:
Mon May 14, 2018 9:36 am
mick.86uk wrote:
Sun May 13, 2018 4:43 pm
Did you get the backend flash done?

I'm looking at getting the JB4 BEF race map flashed tomorrow, just waiting on the android tablet to be delivered so I can load the MHD flasher.
I haven't yet, I've got all the cables and tablet etc but just haven't had time this weekend!
I've flashed mine today!

Impressed with the JB4 BEF maps compared to the standard JB4 maps.

Now feels super smooth and progressive right through the rev range, need to time some 100-200kph on the vbox but feels quicker now.

The cold start noise reduction option has cured my loud rattling BCS exhaust, no longer embarrassing to start it up from cold. :thumbs:
Sounds good to me! I'd be interested in the speed difference between normal JB4 and backend MHD, also does the MHD allow you to do a stage 2+ then JB4 just for safety parameters? Or does it use the JB4 maps?
M135i (2014 Manual) - Custom Stainless Exhaust, JB4, BMS Intake, M4 LCA, Eibach Pro's, Cades Bern Wheels, Reiger Diffuser, Maxton Splitter, Double Slat Grills, M4 Mirror Caps

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