MHD+ Suite

Owned by Nils Bluhm
Last updated: Aug 29, 2024 by Momir
6 min read

MHD+ is the overall encompassing name of our suite of custom features we have added to the DME in order to improve and expand upon its functionality.  Currently we offer MHD+ support for the following vehicles:

  • E-Series (MSD8x DME): N54

  • F-Series (MEVD DME): N13, N55 (PWG and EWG), S55

  • F/G-Series (MG1 DME): B58 gen1

  • G-Series (MG1 DME): B58 gen2, S58

Our main custom MHD+ features include Antilag, Map Switching, and FlexFuel.  Information on how to use each feature (and what is required) can be found in their respective sections below.

Antilag

Antilag can be baked into your custom tuned file by your tuner, or you can use our built-in Antilag flash time option with an OTS map or a custom tuned file.  Here are step-by-step instructions on how to best use the feature!

Rolling Start

  1. Ensure the vehicle is up to operating temperature.

    1. E-Series also requires DSC one press off or fully off.

  2. Select the appropriate gear for your given speed / racing condition.

    1. For AT or DCT transmissions, make sure you are in manual mode so that it does not kick down to a lower gear.

  3. E-Series: pull cruise control stalk in TOWARD you, or hold steering wheel VOL DOWN
    F/G-Series: hold either the cruise control RES button, or the cruise control DOWN rocker switch (both first and second indent work)

    1. NOTE: some early F/G-Series 5/6 series cars are limited to only using cruise control DOWN rocker switch to active antilag.

  4. While continuing to hold the button, gradually fully depress the accelerator pedal.

  5. Wait 1-2 seconds for boost to build and then release the button / stalk!

DCT Launch Control Start

  1. Ensure the vehicle is up to operating temperature.

  2. Engage LC like you normally would.

  3. Once RPMs rise, press and hold either the cruise control RES button or DOW

  4. N rocker switch (both first and second indent work) on F/G-Series, or on E-Series, pull the cruise control stalk in TOWARD you, or hold the steering wheel VOL DOWN button.

  5. Wait 1-2 seconds for boost to build and then release the button / stalk at the same time you release the brake pedal to launch.

Map Switching

Map switching can be added to custom tunes by your tuner, or configured using our new OTS MultiMap capability.  This allows you to have up to 4 switchable maps that can be changed on the fly in a few seconds without having to reflash the vehicle!  This allows you to quickly change between a daily map, race gas map, FlexFuel map (see below section) etc.

For OTS map switching, on the stage / octane selection screen you will see the following new MultiMap section we’ve added:

First select which stage of modification is appropriate for your vehicle.  Then you are free to select whichever octane variants you would like per map slot.

In addition to the octane selections, you can also use the slider to reduce the HP that each map will make.  This is very useful if you would like to make your own valet map, lower power map for cruising, etc.

NOTE: If you plan on using FlexFuel (on the flash options screen, details in the FlexFuel section below), all map slots should be filled with non-ethanol, pump gas selections.

 

Instructions

First, ensure your current tune has been set up for map switching, or you have flashed an OTS MultiMap.  Map switching is then performed in the car by the following steps:

  • E-Series: press and hold the TIP button on the cruise control stalk for 2 seconds, or pressing VOL DOWN and CH DOWN on the wheel at the same time.

  • F/G-Series: press and hold either the cruise control SET/LIM button or the BC button for 2 seconds.

You will see the RPM needle jump to whichever map slot number you have currently selected and the CEL will start blinking slowly.

Now to adjust the desired map selection you will:

  • E-Series: use the cruise control stalk UP/DOWN, or CH UP/DOWN on the wheel

  • F/G-Series: use the cruise control UP/DOWN rocker

To apply the selection (after which RPM needle will return to normal operation and the CEL will stop blinking):

  • E-Series: press and hold the TIP button on the cruise control stalk for 2 seconds, or pressing VOL DOWN.

  • F/G-Series: press and hold either the cruise control SET/LIM button or the BC button for 2 seconds.

General Info

  • You can switch maps on the fly at any time: car running, driving, etc

  • Your currently selected map is saved when the car is shut off and will be restored the next time you start the car.

  • Reflashing the car will reset the currently selected map back to slot 1.

  • The currently selected map can be logged via our new Current Map parameter.

FlexFuel

FlexFuel can be added to custom tunes by your tuner, or added as a flash option for a valid  OTS MultiMap (or single map on N54).  This allows your tune to automatically adjust for any given Ethanol content mix / blend you fill the car with.  It is a true “set it and forget it” setup!  

For OTS FlexFuel, you must first ensure you meet the requirements below.  Next, you will want to select and config a MultiMap tune (see details in section above).  For FlexFuel, you should not select an ethanol map in any map slot, as the ethanol blending is handled automatically with our code.  When you get to the flash options screen, make your ECA (ethanol content analyzer) selection.  You will see another checkbox option appear below it for FlexFuel.  Check that and then flash your map.  Your car will now automatically adjust its tune based on the actual ethanol content in your tank!

Requirements

  • CANBUS based Ethanol Content Analyzer (ECA) Kit

  • N54 also supports the traditional Motiv DMTL Wired ECA kit

  • MHD Monitor License (in addition to Flasher license)

  • OTS pump gas map and E85 map pack licenses (if not custom tuned)

Useful Logging Parameters

  • Ethanol Content (CAN) - this is the ethanol content that is being sent to the DME from your installed CANBUS ECA kit.

  • Ethanol Content (Active) - this is the ethanol content that is currently being used in our custom DME calculations.  It will typically be equal to Ethanol Content (CAN) unless your tuner is overriding the sensor value intentionally.

  • Ethanol Content (Wired) - this is the ethanol content that is being sent to the DME from your installed Motiv DMTL Wired ECA kit on N54

  • Fuel / Load / Timing / Knock Interpolation - these values show you how the individual categories are being blended between your pump gas and ethanol calibrations.

MHD+ Menu System

On supported MHD+ platforms (currently F/G-Series), entering into “mapswitch” mode is not only just for mapswitch.  It is actually a more advanced paged menu system, with 3 different “pages” as of current release.  You enter into the menu system the same way you did mapswitch (F/G-Series: press and hold either the cruise control SET/LIM button or the BC button for 2 seconds).  You will always enter on “page 1”, which is designed by a pattern of one CEL blink at a time.

To change pages, quickly press the SET/LIM button or the BC button. The current page is always indicated by the blink pattern of 1 / 2 / 3 blinks in a row.  To exit the menu, press and hold again like you did to enter.  Page details are as follows:

Page 1 - Mapswitch

This is the normal map switch you are used to.  UP/DOWN on the cruise control rocker will move the RPM tach to your desired map selection.  If you only have 1 active map slot, you will not be able to move the tach from 1000 rpm.  You will still have access to page 2 and 3 though. 

Page 2 - Exhaust Flap Control

Page 2 allows you to control your vehicle’s exhaust flap on the fly.  There are three settings you can switch between (again using the UP/DOWN rocker).

  • 0 rpm = OEM exhaust flap control, no forced override

  • 1000 rpm = exhaust flap always forced open

  • 2000 rpm = exhaust flap forced closed (note: this will only apply up until a certain load threshold for safety)  

Page 3 - Ethanol Content Quick View

Page 3 will show the current Ethanol percentage of your fuel (when using an appropriate CANBUS ECA kit).  1000rpm = 10% Ethanol, up to 7500 rpm = 75% ethanol.  If you need to see E% greater than that, you should log it or place it on an MHD Monitor gauge.

 

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MHD User Guide