VEMS is a DIY fuel injection system for automobiles, motorcycles, boats or other gasoline driven applications.

Former, simpler featureset version (from mostly the same authors) was MegaSquirtAVR. MegaSquirtAVR was an implementation with similar basic featureset (though extended in significant ways) as the B&G MegaSquirt design (or any other injection controller, like the GM design that gave the idea to B&G),

No parts of the MegaSquirt firmware were used (obviously, since the MegaSquirt assembly code does not run on the more advanced processor), and no parts of the MegaSquirt PCB were used.
It was decided that one of the configuration interfaces is made compatible with MegaTune, with a customized profile. MegaTune is an easy to use windows, GUI based tuning-software (released under GNU General Public Licence), by no accident the same is used by MegaSquirt.
Stepper motor or PWM solenoid based idle air control was a basic feature from the start, as well as directly attached PS2 keyboard and LCD interface.
8 channel Ignition and embedded wideband oxygen sensor controller was added in 2003, along with knock sensing, multiple versatile configurable outputs, and other advanced improvements that were not available in the MegaSquirtAVR.
Interestingly, MegaSquirt advocates spread false claims that VEMS "stole MegaSquirt". This has no basis: not a single line was used (it would be impossible, because the more advanced microcontroller does not run MegaSquirt assembly language!), and not a square-cm of PCB was copied either: a from scratch hardware and from scratch firmware. Actually, MegaSquirt only had a very small subset of the functionality of the 2003 VEMS design (some of VEMS extra functions were added later, and some are not available in megasquirt, even today). MegaSquirt authors (instead of competing in functionality) killed and continuously keep killing any reference to VEMS (eg. when mentioned by a helpful user) in their user forums to prevent users from discovering (and migration to) the more advanced system.
The opensource MegaTune tuningsoftware is used, and the documention is also opensource. Consult the licence of each part to find out details.

The power of the VEMS design partly comes from the

Fetures under construction
  • Even more versatile configuration
  • Ion-sense feedback based closed-loop ignition control for knock avoidance and optimal power.