I'll kick in some info,... oh and some pics for views.
I'll try to get some more info in here once I get to work,...it *is* Fri after all!!
This is a group for everyone who is installing the Megasquirt system onto their Audi or VW to share information and ideas.
-real-time fuel calculations up to 16,000 RPM!
- instant re-programming of constants, enrichments, etc. while the vehicle is running
-supports rev limiter by fuel cutoff. RPM limit and reengage RPM can be
adjusted. Pulsewidth at fuel cutoff can be adjusted.
-on-board Manifold Absolute Pressure (MAP) sensor (Motorola MPX4115)
-MAP sensor is additionally used to obtain the barometric pressure during engine startup, in order to determine a barometric pressure correction factor.
-Air density corrections as a function of manifold air temperatue (MAT) and barometric pressure effects on VE are pre-computed as lookup tables and properly used by the ECU in the fuel calculation. Most aftermarket EFI controllers allow the user to set the air temperature correction - MagaSquirt uses the mathematical equation for air density to generate this correction, so no user intervention is required. More importantly, many aftermarket EFI controllers do not take account the effect of barometric pressure change to volumetric efficiency. This correction comes into play at high altitudes (i.e. low barometric pressures). MegaSquirt uses a lookup table to determine this correction, and is consistent with OEM systems.
-specific RPM and MAP range points are adjustable by the end user
-There is an output control signal (current sink up to 500ma) designed to drive an idle bypass solenoid (open/close solenoid, not a stepper), which allows the addition of more air at idle during warmup. The activation/deactivation temperature is set by the user.
-A relay drive circuit (up to 500 ma) is provided to control power to the fuel pump. Signal is active while the engine is cranking or running, and will deactivate 2 seconds after the last ignition event.
-option of using either SD or Alpha-N.
-Can handle throttle-body injection, can control individual port injectors
-Other people have developed and shared helpful freeware / hardware for MegaSquirt, including:
MegaTune - for tuning and datalogging MegaSquirt with a laptop
MegaTweak3000 - for refining your volumetric efficiency table from datalogged data
EasyTherm - to simplify the substitution of non-standard temperature sensors and to upload software revisions.
MS Palm - to tune and datalog with a Palm
MegaView - to provide a dedicated dash display
-The TPS sensor tells MegaSquirt what the current position of the throttle. This variable is compared to the most recent readings to determine if the throttle is opening or closing rapidly. If so, extra fuel can be added for an opening throttle to compensate for transient conditions. This functions the same as an accelerator pump in a carburetor.
-The TPS also does two other important functions. First, if the throttle is open more than a specified amount during cranking, it invokes the “flood clear” mode by reducing the injected pulsewidth to 0.3 milliseconds. Second, if the throttle is open more than 70%, exhaust gas feedback is shut off.
-options to shut off EGO correction below a specified coolant temperature or below a specified engine rpm.
-works off of signal from coil or dizzy hall sensor for ignition,..no need for special toothed wheels or magnets.
-capability to fully exploit a wide-band sensor by incorporating full time, all conditions closed loop feedback for fuelling with real-time updating of the VE table
There is now a software interface to tune/datalog MegaSquirt from Unix/Linux