Megasquirt Product Comparison |
Introduction
The Megasquirt product range offers from the 'cheap and cheerful' batch fire fuel-only in full DIY assembly to full sequential fuel and spark on a V8 with a pre-assembled ECU. The traditional Megasquirt range originated as fully DIY products, while today fullly off-the-shelf units are available to suit professional race teams and tuners.
This is an archive page. Click here for full details of the Megasquirt product range.
Megasquirt-3 with MS3X
This is the present top of the range ECU in the 'traditional' Megasquirt range. It has 8 fuel and 8 logic spark outputs offering full sequential fuel and spark for hi-z injectors and logic level coil-on-plug coils (or high-current coils with suitable external ignition module.) This supports full-sequential on a V8 or semi-sequential with wasted spark on a V12. Spark and fuel are fully trim-able per channel and injector timing is mappable for optimum power (~1% gain available) Six relay or solenoid outputs for nitrous, boost, fan control, shift light, tachometer outputs etc. Switch inputs for launch, idle-up, nitrous-in etc. and additional sensor inputs for external MAP sensors or measuring pre/post intercooler etc. On-board SD-card datalogging allows fast datalogging without the need for a laptop while logging. Built-in USB-serial adapter eases connection to modern laptops.
CAN communication ability to interface with extender boards for more inputs and outputs on the more complex installs - e.g. multiple EGT, multiple widebands, speed sensors etc. Calibration to adapt to OEM temperature sensors is straightforward and numerous wideband calibrations are supported.
Initial setup is aided by test modes for the fuel and spark and by built-in tooth loggers to help diagnose incoming tach signals.
The MS3 software includes many 'race' type features, two stages of progressive nitrous, water injection, closed loop boost control etc. Vehicle speed sensing, logging of EGT (with external hardware.)
In most configurations, the MS3 + MS3X +V357 can be used by setting a few configuration jumpers inside the box. It requires little or no DIY effort inside. (Other Megasquirt options are far more DIY intensive.)
Megasquirt-3 without MS3X
This gives all the software features of the full Megasquirt-3 but does not include the driver board to support 8 channel fuel and spark, relay outputs or switch or analogue inputs. Included is batch-fire fuel, SD card logging and USB-serial.
This option may be of use to the more DIY orientated user who wants to add their own options or as an upgrade from Megasquirt-1 or Megasquirt-2.
Megasquirt-2
Megasquirt-2 gives many options, but most will require DIY customisation by the end user (or builder.) Up to 4 cylinder sequential fuel and 6 cylinder coil-on-plug are supported, various race features and CAN communications. Much of the tuning interface is very similar to the Megasquirt-3. No SD-card logging and communication are serial only as standard.
Megasquirt-2 uses the same calibrations, test modes and diagnostic loggers as Megasquirt-3.
Microsquirt
Microsquirt offers similar features to Megasquirt-2 but comes pre-assembled in a case and is half the size. It offers two fuel outputs, four ignition outputs and two crank/cam tach inputs as standard. However, it requires an external add-on to support 4 wire stepper idle.
Microsquirt module
The Microsquirt-module comes as a bare PCB and is most often used to form the core of a packaged ECU. For example, the DIY-PnP range from DIYAutotune use the Microsquirt module at the heart. The module is specifically intended to form part of your product with licensed B&G hardware and firmware of your choice. It is not intended for novice end-users.
Megasquirt-1
Megasquirt-1 offers a cost effective entry level to the aftermarket ECU market. Coupled with an EDIS module, the Megasquirt-1 V2.2 was cheap but gave mappable spark and fuel. For direct coil control (non-EDIS) the Megasquirt-1 V3.0 is still a cheap and simple ECU. As expected Megasquirt-1 lacks many of the features of the newer ECUs. Few OEM wheel patterns are supported, temperature sensor and wideband calibration is more tricky and there are fewer diagnostics. All features require DIY modifications to the circuit board.
The processor used within the Megasquirt-1 is now obsolete and will become
unavailable once supplies are exhausted.
It is strongly recommended that you consider Megasquirt-2, Microsquirt or Megasquirt-3 products instead.
This table shows the maximum features available for each option.
Feature / Version |
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Product Picture |
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Summary |
Single board, with plugin CPU, can be DIY assembly. Lowest cost entry level. Limited features. Complicated trigger wheel configuration. Difficult temperature sensor calibration. Obsolete processor chip. |
Single board, with plugin CPU card, can be DIY assembly. Better tunability, driveability and diagnostics than Megasquirt-1. |
Single pre-assembled board, no DIY. Similar to Megasquirt-2. Four ignition outputs. |
Module forms core of an ECU that you buy or build. Same technology as Microsquirt, but more outputs accessible. |
Main board, can be DIY assembly, plugin CPU card, plugin extension card. All MS2, plus more I/O, SDcard logging, USB. Expandable to sequential fuel and spark. |
Main board, can be DIY assembly, plugin CPU card, plugin extension card. All MS2, plus 8cyl sequential fuel and logic spark, more I/O, SDcard logging, USB. |
Connectors |
Standard D-type |
Standard D-type |
AMPseal |
Pin header |
Standard D-type |
Standard D-type |
Built in Hardware |
|
|
|
|
MS3 on V3.0, V3.57 board |
MS3 with MS3X on V3.0, V3.57 board |
|
2x fuel channels hi-z, low-z with PWM limiting |
2x fuel channels hi-z, low-z with PWM limiting |
- |
- |
2x fuel channels hi-z, low-z with PWM limiting |
2x fuel channels hi-z, low-z with PWM limiting |
|
- |
- |
2x fuel channels without PWM |
2x fuel channels without PWM |
- |
8x fuel channels without PWM |
|
2 wire PWM idle (mod needed on V3.0) |
2 wire PWM idle (mod needed on V3.0) |
2 wire PWM idle |
2 wire PWM idle |
2 wire PWM idle |
2 wire PWM idle 3 wire PWM idle |
|
- |
4 wire stepper idle |
4-wire stepper add-on available. |
4-wire stepper add-on available. |
4 wire stepper idle |
4 wire stepper idle |
|
Fuel pump relay control |
Fuel pump relay control |
Fuel pump relay control |
Fuel pump relay control |
Fuel pump relay control |
Fuel pump relay control |
|
CLT, MAT, TPS inputs |
CLT, MAT, TPS inputs |
CLT, MAT, TPS inputs |
CLT, MAT, TPS inputs |
CLT, MAT, TPS inputs |
CLT, MAT, TPS inputs |
|
2.5 bar MAP sensor |
2.5 bar MAP sensor |
- |
- |
2.5 bar MAP sensor |
2.5 bar MAP sensor |
|
Magnetic (VR) , hall, optical, points tach input (No VR on V2.2 board) |
Magnetic (VR) , hall, optical, points tach input (No VR on V2.2 board) |
2 x Magnetic (VR) , hall, optical, points tach input |
2 x Magnetic (VR) , hall, optical, points tach input |
1x Magnetic (VR) tacho input 1x hall, optical, points tach input
|
2x Magnetic (VR) , hall, optical, points tach inputs
|
|
1x high current coil driver |
1x high current coil driver |
- |
- |
1x high current coil driver |
1x high current coil driver |
|
- |
- |
2x logic level coil |
2x logic level coil |
- |
8x logic level spark |
|
- |
- |
2x medium current outputs |
2x medium current outputs |
- |
6x medium current outputs (e.g. nitrous, boost, VVT, fan, etc.) |
|
- |
|
1x spare analogue inputs |
2x spare analogue inputs |
- |
3x spare analogue inputs |
|
- |
- |
1x switch input (flex) |
2x logic input |
- |
4x switch inputs |
|
- |
- |
1x low current output |
1x low current output |
3x low current output (LEDs) |
3x low current output (LEDs) |
|
- |
- |
- |
3x logic output |
- |
1x logic output |
|
- |
- |
- |
- |
2x raw analogue inputs |
2x raw analogue inputs |
|
- |
- |
- |
- |
SDcard slot for datalogging |
SDcard slot for datalogging |
|
RS232 serial tuning |
RS232 serial tuning |
RS232 serial tuning |
RS232 serial tuning |
RS232 serial tuning |
RS232 serial tuning |
|
- |
CAN communications |
CAN communications |
CAN communications |
CAN communications |
CAN communications |
|
- |
- |
- |
- |
USB serial tuning |
USB serial tuning |
Optional hardware (DIY) |
|
|
|
|
|
|
|
|
|
|
|
User can DIY the same outputs as MS2/Extra if desired or use a combination of the logical outputs normally sent to the MS3X card. |
MS3X already provides most of these options so no DIY required. These options are for additional inputs and outputs. |
|
Up to 6 high current coil drivers |
Up to 6 high current coil drivers |
- |
|
Up to 6 high current coil drivers |
Up to 6 high current coil drivers |
|
2x spare analogue inputs |
2x spare analogue inputs |
- |
- |
2x spare analogue inputs |
2x spare analogue inputs |
|
Launch/nitrous/ tableswitching inputs |
Launch/nitrous/ tableswitching inputs |
- |
- |
Logic inputs can be used for switches |
Logic inputs can be used for additional switches |
|
Relay drivers for nitrous |
Relay drivers for nitrous |
- |
- |
Logic outputs can be used for power drivers |
Logic outputs can be used for additional power drivers |
|
Boost output |
Boost output |
- |
- |
All spare pins on MS3 card can be used for custom fuel and spark |
(Already provided on MS3X) |
|
Fan control output |
Fan control output |
- |
- |
as MS2 |
(Already provided on MS3X) |
|
Tacho output |
Tacho output |
- |
- |
as MS2 |
(Already provided on MS3X) |
|
MAP sensor upgrade to 3 bar, 4 bar |
MAP sensor upgrade to 3 bar, 4 bar |
External MAP sensor |
|
MAP sensor upgrade to 3 bar, 4 bar |
MAP sensor upgrade to 3 bar, 4 bar |
Firmware features |
|
|
|
|
|
|
Fuel table size |
12x12 |
12x12 or 16x16 |
12x12 or 16x16 |
12x12 or 16x16 |
16x16 |
16x16 |
Fuel table resolution |
1% |
1% |
1% |
1% |
0.1% |
0.1% |
rpm resolution |
100 rpm |
1 rpm |
1 rpm |
1 rpm |
1 rpm |
1 rpm |
Accel enrichment |
TPS, MAP, RPM |
Simple (TPS,MAP), Enhanced (wall-wetting) |
Simple (TPS,MAP), Enhanced (wall-wetting) |
Simple (TPS,MAP), Enhanced (wall-wetting) |
Simple (TPS,MAP), Enhanced (wall-wetting) |
Simple (TPS,MAP), Enhanced (wall-wetting) |
Spark table size |
12x12 |
12x12 |
12x12 |
12x12 |
16x16 |
16x16 |
Advance resolution (commanded) |
0.3 deg |
0.1 deg |
0.1 deg |
0.1 deg |
0.1 deg |
0.1 deg |
Injector phasing |
Bank/batch fire, pseudo random, crank based. |
Bank/batch fire Semi sequential for 4-cyl (DIY options for 4cyl sequential) |
Bank/batch fire Semi sequential (4cyl) |
Bank/batch fire Semi sequential (4cyl) |
Bank/batch fire (DIY required for more) |
Bank/batch fire Fully sequential (up to 8cyl) |
Injector timing |
Not adjustable |
Timed within crank pulses or timed for start, middle, end of injection pulse |
Timed within crank pulses or timed for start, middle, end of injection pulse |
Timed within crank pulses or timed for start, middle, end of injection pulse |
Timed for start, middle, end of injection pulse |
Timed for start, middle, end of injection pulse |
Injector trim |
Not adjustable |
Mapped trim table per cylinder when running sequential. |
Mapped trim table per cylinder when running sequential. |
Mapped trim table per cylinder when running sequential. |
Mapped trim table per cylinder. |
Mapped trim table per cylinder. |
Spark trim |
Not adjustable |
Not adjustable |
Not adjustable |
Not adjustable |
Mapped trim table per cylinder |
Mapped trim table per cylinder |
EDIS |
Y |
Y |
Y |
Y |
Y |
Y |
Distributor spark |
Y |
Y |
Y |
Y |
Y |
Y |
Trigger return dizzy |
Y |
Y |
Y |
Y |
Y |
Y |
Simple wheel decoding |
Y |
Y |
Y |
Y |
Y |
Y |
Every tooth wheel decoding |
N |
Y* |
Y* |
Y* |
Y* |
Y* |
Wasted spark |
Y |
Y |
Y |
Y |
Y |
Y |
Coil on plug |
Y |
Y |
Y |
Y |
Y |
Y |
Dual dizzy |
Y |
Y |
Y |
Y |
Y |
Y |
Cam / 2nd tach input |
Y |
Y |
Y |
Y |
Y |
Y |
Number of spark outputs |
6 |
6 |
2 |
2 |
8 |
8 |
Rotary trailing |
Y |
Y |
Y |
Y |
Y |
Y |
HEI7, GMDIS |
Y (with bypass control) |
Y (with bypass control) |
Y (with bypass control) |
Y (with bypass control) |
Y (with bypass control) |
Y (with bypass control) |
TFI |
Y |
Y |
Y |
Y |
Y |
Y |
Oddfire wheel decoder |
Y |
Y |
Y |
Y |
Y |
Y |
Oddfire dizzy |
N |
Y |
Y |
Y |
Y |
Y |
Neon/420A |
Y |
Y |
Y |
Y |
Y |
Y |
36-1+1 |
N |
Y |
Y |
Y |
Y |
Y |
36-2-2-2 |
N |
Y |
Y |
Y |
Y |
Y |
Subaru 6/7 |
N |
Y |
Y |
Y |
Y |
Y |
IAW Weber-Marelli |
N |
Y |
Y |
Y |
Y |
Y |
Mitsubushi 6g72 |
N |
Y |
Y |
Y |
Y |
Y |
4/1 CAS |
Y |
Y |
Y |
Y |
Y |
Y |
4G63 (Miata) |
Y |
Y |
Y |
Y |
Y |
Y |
99-00 Miata |
N |
Y |
Y |
Y |
Y |
Y |
Renix 44-2-2 |
Y |
Y |
Y |
Y |
Y |
Y |
Twin trigger (aka. dual spark) |
N |
Y |
Y |
Y |
Y |
Y |
Suzuki Swift |
Not with std code |
Y |
Y |
Y |
Y |
Y |
Suzuki Vitara |
N |
Y (Untested!) |
Y (Untested!) |
Y (Untested!) |
Y (Untested!) |
Y (Untested!) |
Daihatsu 3 cyl |
N |
Y (Unproven) |
Y (Unproven) |
Y (Unproven) |
Y (Unproven) |
Y (Unproven) |
Daihatsu 4cyl |
N |
Y (Untested!) |
Y (Untested!) |
Y (Untested!) |
Y (Untested!) |
Y (Untested!) |
Rover K Series 36-1-1 |
N |
Y |
Y |
Y |
Y |
Y |
Rover K Series 36-1-1-1-1 |
N |
Y |
Y |
Y |
Y |
Y |
Rover K Series 36-2-2 |
N |
Y (Untested!) |
Y (Untested!) |
Y (Untested!) |
Y (Untested!) |
Y (Untested!) |
Honda VTR1000 12-3 |
N |
Y |
Y |
Y |
Y |
Y |
Chrysler 2.2/2.5 |
N |
Y |
Y |
Y |
Y |
Y |
GM 7X native |
N |
Y |
Y |
Y |
Y |
Y |
Nissan 360 tooth CAS |
N |
N/P> |
N |
N |
SR20, RB25 |
SR20, RB25 |
Load methods |
SD, AN, MAF |
SD, AN, map/baro (load%), ITB |
SD, AN, map/baro (load%), ITB |
SD, AN, map/baro (load%), ITB |
SD, AN, map/baro (load%), MAF, ITB |
SD, AN, map/baro (load%), MAF, ITB |
Load blending |
Y? |
Y |
Y |
Y |
Y |
Y |
Load tables |
1 |
2 |
2 |
2 |
2 |
2 |
Staged injection |
Y |
Y |
Y |
Y |
Y |
Y Includes sequential staging and multiple banks. |
Over-run fuel cut |
Y |
Y |
Y |
Y |
Y |
Y |
Tachometer output |
Y |
Y |
Y |
Y |
Y |
Y |
Launch Control/flat shift |
Y |
Y |
Y |
Y |
Y |
Y |
Spark cut rev limit |
Y |
Y |
Y |
Y |
Y |
Y |
Dwell duty% |
Y |
Y |
Y |
Y |
Y |
Y |
Dwell battery correction |
built-in |
table of %ages |
table of %ages |
table of %ages |
table of %ages |
table of %ages |
Cranking pulsewidth |
table of pulsewidths |
table of %ages |
table of %ages |
table of %ages |
table of %ages |
table of %ages |
Alternate cranking injection |
N |
Y |
Y |
Y |
Y |
Y |
Specific cranking advance, dwell |
Y |
Y |
Y |
Y |
Y |
Y |
Fixed timing for setup |
Y |
Y |
Y |
Y |
Y |
Y |
Test mode |
N |
Pump, Inj, Coils, Idle |
Pump, Inj, Coils, Idle |
Pump, Inj, Coils, Idle |
Pump, Inj, Coils, Idle |
Pump, Inj, Coils, Idle |
Closed loop idle control |
Experimental |
Y |
Y |
Y |
Y |
Y |
Boost control |
Open loop |
Y (open or closed loop with PID control) |
Y (open or closed loop with PID control) |
Y (open or closed loop with PID control) |
Y (open or closed loop with PID control) |
Y (open or closed loop with PID control) |
Nitrous control |
Y |
Y (2 stage) |
Y (2 stage) |
Y (2 stage) |
Y (2 stage progressive) |
Y (2 stage progressive) |
Knock sensor (software) |
Y |
Y |
Y |
Y |
Y |
Y |
Realtime barometric correction |
Y |
Y |
Y |
Y |
Y |
Y |
Water Injection |
Y |
N |
N |
N |
Y |
Y |
Table Switching |
Y |
Y |
Y |
Y |
Y |
Y |
Configurable outputs |
Y |
Y |
Y |
Y |
Y |
Y |
AFR target tables |
Y |
Y |
Y |
Y |
Y |
Y |
Dual fuel tables (per bank) |
Y |
Y |
Y |
Y |
Y |
Y |
Synchronous sensor sampling |
N |
Y |
Y |
Y |
Y |
Y |
CAN communications |
N |
Y |
Y |
Y |
Y |
Y |
Built in tooth/trigger loggers |
Y (tooth and trigger) |
Y (tooth, trigger, composite, sync-errror) |
Y (tooth, trigger, composite, sync-errror) |
Y (tooth, trigger, composite, sync-errror) |
Y (tooth, trigger, composite, sync-errror) |
Y (tooth, trigger, composite, sync-errror) |
* = see notes below
Megasquirt 1 - B&G firmware - MS1/Extra firmware
Megasquirt 2 - B&G firmware - MS2/Extra firmware
Microsquirt - B&G firmware - MS2/Extra firmware
Microsquirt module - B&G firmware - MS2/Extra firmware
Notes on boards
The Megasquirt 1 and 2 may use a V2.2, V3.0 or V3.57 mainboard. The Megasquirt 3 may use a V3.0 or V3.57 mainboard. The V2.2 and V3.0 are available in DIY kit form. If you wish to DIY, the V3.0 is recommended as it has an inbuilt magnetic input (VR) circuit and better support for low-z injectors. The V2.2 is the simplest and cheapest option but is technically obsolete and does not include the VR conditioner or low-z support. The V3.57 is a pre-assembled version of the V3.0.
The features chart is based on using a V3.57. The only real difference when using the V3.0 is that a small modification is required to adequately support PWM idle. If you are considering adding circuits then the V3.0 is likely a better choice as it has a prototype area provided for the purpose.
When using the MS3, the MS3X expander board already contains many input and output options and the MS3, MS3X, V3.57 is a recommended package.
Notes on firmware features
For Megasquirt 1, the features listed are those from MS1/Extra code 029y4
For Megasquirt 2, Microsquirt and Microsquirt Module, the features listed are those from MS2/Extra code 2.1.0
Megasquirt3 are using their own latest firmwares.
Explanation of the terms in the table
Fuel Table Size: The number of cells in the fuel tuning table. Note that because the rpm and load values are adjustable a good tuner is unlikely to need more than 12x12.
PW resolution: The step size of increments of fuel pulsewidth. In theory the smaller the step, the finer the control available. Whether this translates into better engine performance is largely impacted by how well the engine is tuned and operating factors. MS1/Extra hi-res allows better injector resolution by using a timer for injector control but loses injector PWM control in the process. Note that the fuel calcs will often have a lot of inbuilt fuzziness, so the 0.67us hardware precision may not be useful.
RPM resolution: The MS1 codes only use rpm in steps of 100 internally, so this means you can only tune in 100rpm steps. Not a big deal.
Accel enrichment: There are various methods of responding to acceleration transients for best engine driveability.
Advance table size: All present Megasquirt versions with spark control use a 12x12 table for setting the advance at different loads and rpms. Megasquirt 3 extends this to 16x16
EDIS: Ford's standalone ignition control system
Distributor spark: Simple spark control using a single coil and typically a distributor mounted pickup, crank mounted pickups can also be used.
Trigger return dizzy: Some distributors with hall effect sensors have a shutter wheel that provides “cranking” and “running” signals on each edge. This can give improved starting ability and also better running precision.
Simple wheel decoding: The MS1/Extra wheel decoder can decode regular wheel patterns (36-1, 24/2, 60-2, 24/1) but gains no timing improvement from the additional teeth. The early MS2 wheel decoder worked in a similar way.
Every tooth wheel decoding: The MS2/Extra code samples the time between each tooth for speed data and sets the advance/dwell as a tooth number plus a time offset. Unsure what MS2 base does.
Wasted spark: i.e. multiple spark outputs. Without modifications to the MS2 card, MS2 base code can only do single spark output. The modifications also remove the ability to control low-Z injectors using PWM - resistor packs would be required.
Coil on plug: As above, but additional code is required to decode the trigger wheel.
Dual Dizzy: For engines like the Lexus V8 where a trigger wheel and two coils and distributors are used.
Cam / 2nd tach input: For any coil on plug install a phase sensor is required. Any engine with a non-missing tooth main wheel also requires a 2nd tach input. MS2 can do this with modifications to the card. Microsquirt has it as standard.
Number of spark outputs: This determines how many coils you can drive.
Rotary trailing: Specific code to drive the trailing coils with programable split angles.
HEI7/GMDIS: An ignition system from GM. The bypass output controls inbuilt timing or controlled timing. A dedicated output alleviates the need for an external relay.
TFI: An ignition system from Ford.
Oddfire wheel decoder: Using a regular trigger wheel to drive coils on an oddfire engine that requires an angular offset between the outputs.
Oddfire dizzy: Some engines such as GM V6 use an oddfire pattern and a distributor. This code detects and works with the uneven pattern.
Neon/420A, 36-1+1, 36-2-2-2, Subaru 6/7, IAW Weber-Marelli, Mitsubushi 6G72, 99-00 Miata, Suzuki Swift, Suzuki Vitara, Daihatsu 3cyl, Daihatsu 4cyl: These are all special wheel decoders for these specific engine and trigger wheel patterns. See the main page for links to pages about these wheels.
CAS 4/1: This is handled as part of the wheel decoder.
Twin trigger / Dual spark: This is often used on 4 cylinder bike engines. A single lobe is mounted on the crank shaft and two pickup coils detect it passing. MS2 and MS2/Extra support this with different code implementations.
Load methods: SD = speed density, standard MAP sensor input. AN = alpha-N - TPS and RPM. MAF = using a Mass Air Flow sensor. Map/baro = a variant on speed density that better allows for altitude changes.
Load blending: Combining multiple load methods for smoother transition from idle to full load.
Load tables: How many load tables operate at one time.
Staged injection: Inspired by RX7 and similar. For use where two banks of dissimilar injectors are used. e.g. you can have a bank of small injectors for idling and low load and a second bank of large injectors for full load operation. The code automatically enables the second bank as and when required. This can greatly improve the fuel regulation under low load.
Over-run fuel cut: A standard feature in most fuel injection systems since the 1980s. Fuel can be cut off totally under heavy deceleration conditions to conserve fuel.
Tachometer output: When using a complex trigger wheel or wasted spark a special output is often required to drive the tachometer.
Launch control/flat shift: A “two step” rev limiter primarily used for racing.
Spark cut rev limiter: A method of limiting revs. It is far harsher than a simple engine-preserving fuel cut, but works very well for launch/flat shift.
Dwell duty%: For some ignition systems like TFI or MSD a percentage dwell output is required instead of a coil charge dwell. This allows various percentages to be set in software.
Dwell battery correction: As the supply voltage varies, the required dwell time also changes. Different methods for achieving this.
Cranking pulsewidth: How the fuel injected during cranking is controlled. A percentage table is supposed to allow first time setup as the number is scaled based on the injector size. The latest MS2 codes also take X-Tau, air density and flex fuel into account.
Alternate cranking injection: The standard scheme is to inject fuel once per ignition event. On large cylinder counts this can result in low precision and difficult start. This option allows the number of injections to be halved to allow better control.
Specific cranking advance, dwell: A specific setting for the cranking advance and dwell instead of a table lookup.
Fixed timing: A setting to lock the timing for easier first time setup and confirmation that the ignition system is working correctly.
Test mode: Various modes for testing system components without running the engine.
Idle valve control: Options for different types of fast idle valve.
Boost control: Mode to control the wastegate on a turbo to vary boost levels.
Nitrous control: Control system to only allow nitrous when certain conditions are met, add more fuel, retard the timing etc. also delay nitrous after launch.
Knock sensor: Take feedback from a knock sensor and retard the timing
Realtime baro: Input from a second map (pressure) sensor for continual barometric adjustment. Useful in mountainous regions. Not much use in the Netherlands.
Water injection: Specific system to control water injection solenoids and pumps.
Table Switching: An external switch input swaps the fuel or spark tables being used. Note - this is not for “economy vs race” - that is a common misunderstanding of fuel injection systems and that is what your right foot is for. Valid examples are nitrous or swapped fuel.
Configurable outputs: Various on/off outputs for fans and warning lights etc.
AFR target tables: Using your wideband to target different mixtures and different rpm/loads.
Automatic Mixture Control: The ECU responds to the wideband input and adjusts the fuel VE table automatically. As an alternative use “Auto Tune” in the tuning software.
Dual Fuel tables (per bank): Another name is Dual table. Originally written for mapped water injection. Can also be used on V engines for different tuning on each bank. Do not confuse with staged injection.
Synchronous sensor sampling: The sensors are sampled at a particular crank angle. This gives far more repeatable response on the MAP sensor signal on most engines.
CAN communications: The MS2 and Microsquirt have CAN communications built in which allow communications with addon boards. ( See also here. )
Crank based injection points: MS2/Extra 2.0 can do a semi-sequential which has improved the idle on 4G63 engines for sure. MS3 can do fully sequential.
(C) James Murray 2009, 2010