A popular thread in this forum called "Performance Upgrades"
discusses such modifications as turbocharging, supercharging, header and exhaust upgrades, transmission swaps, cool air induction and other power increases. It also explored the idea of replacing the Bosch D or K jetronic with the MegaSquirt EFI controller and several users (myself included) had done the conversion or were in the process of doing so and there seems to be some interest from others in this specific MegaSquirt project.
In the interest of keeping the original thread on topic about the many possible performance upgrades to vintage Mercedes I'm starting this new thread to discuss specifically the MegaSquirt conversion. I will post to the other thread only when my MS project is completed and can comment on its merits as a "performance upgrade" or when I finally get around to fabricating headers and completing other non MS modifications.
MegaSquirt is a stand alone user-programmable control (via laptop) for spark and fuel and can be adapted to any spark controlled engine with the right choice of components. The conversion can be seperated into two phases (fuel and spark) and each phase can be done completely independently of the other while maintaining vehicle driveability. Here's a summary (vastly simplified) of the conversion from the Bosch K-jetronic CIS to MegaSquirt EFI in my 1978 450 SEL:
Phase 1. FUEL
-- Remove the Bosch CIS components consisting of mechanical fuel injectors, fuel distributor, air flow sensor assembly and miscellaneous warmup and enrichment devices; they will no longer be used.
-- Acquire MegaSquirt II v3, relay board, wiring harness bundle, wideband O2 sensor and controller, set of 8 Bosch 19 lb/hr fuel injectors and fuel pressure regulator (used from Ford Mustang), fuel rail from earlier Mercedes EFI, coolant temp sensor, intake air temp sensor and throttle position sensor (all cheap, stock GM parts).
-- Install all of the above (there will need to be some fabricating of brackets and other "adaptive engineering" to accomplish this) and use the MS software with a laptop to load the default fuel maps to get the engine runnning and then drive around to datalog. Software will revise fuel maps to optimise for peak power at or near WOT and for maximum fuel economy at other times.
Phase 2. SPARK
-- Remove distributor, coil and ignition control module; they will no longer be used.
-- Acquire EDIS 8 module plus coils and wires (used from Ford Mustang), 36-1 trigger wheel and sensor and the necessary wiring.
-- Install all of the above (also requiring "adaptive engineering") and use the MS software to load timing tables. Datalog and revise map for optimal performance.
User 'oughtsix' has succesfully done phase 1 of this conversion
and I invite him to post a summary here on this thread. He's done a lot of pioneering work for this particualar setup and has extensive and very useful pictures. I've been documenting extensively as well, and as soon as I can set up a place to host, I'll post pictures, too. Others who are now doing or are interested in doing the MegaSquirt conversion should start posting their projects.
note: MegaSquirt has a large support community and forums for many applications. MegaSquirt EFI :: Index
I have no affiliation or relationship whatsoever with MegaSquirt.