Megasquirt and megajolt

megasquirt= injection and ignition.
gives you a fully mappable ignition and injection system, irrespective of what each part came from. has lots of uses, from eliminating troublesome stock engine management that cant be separated from immobiliser systems on modern engines, to running injection with aftermaket throttle bodies.

megajolt= ignition only. typically used in conjunction with carbs on an engine that has distributorless ignition.

yep, pretty much. its tied into using a few specific components as far as i know, like 36-1 trigger wheels, but aside from that, its pretty adaptable. it is entirely possible to use it to get bike throttle bodes to work on a modern efi engine, providing you can get all the sensors talking to each other. i struggle to get my head round some of it, ive been doing a few megajolt setups to get used to that before i 'move up' to megasquirt, but as far as i understand it, the principles are the same except megasquirt uses a 'proper' ecu to control the sparks, whereas a mejajoint unit basically piggybacks with a ford EDIS unit to control ignition.

Megasquirt started as a purely fuel injection thing to be used with the sparks provided by the car's existing ignition system.

There are several variants of the hardware. The original processor (and standard software) - called an MSI - only does fuel and doesn't do sparks. However, you can use "MS Extra"* code on an MSI processor to do sparks as well. The later processor - MSII - is more powerful and does sparks out-of-the-box. in addition to the different processors, there are a coupe of different circuit boards floating about as well - the V3 is more flexible for modifications than the V2.2, but is a little more expensive (if you can still find a V2.2 - dunno, haven't looked in ages).

In order to calculate the amount of fuel required, several sensors are required (air temp, coolant temp, lambda, etc.) - the MS design uses GM sensors as standard, but others can be supported. In fuel-only guise, you connect an input to the ignition coil so it can read the engine's speed. There's a Manifold Absolute Pressure (MAP) sensor built into the MS ECU to detect how much load the engine's under - more load requires more fuel so it doesn't melt at what.

When adding spark control as well, you can either use the Ford EDIS (Electronic Distributorless Ignition System) setup - which uses a module and a 36-1 trigger wheel to generate the spark itself but receives a signal from the MS ECU to control the amoutn of advance - or you can run a speed sensor (doesn't have to be 36-1) directly into the MS ECU and use that to control the ignition coil(s) directly.

All the fuelling maps etc. are adjustable over a PC-based interface.

You'll have to set up the "injection hardware" yourself - that's throttle bodies, manifolds, injectors, fuel pipes, fuel pressure regulators, etc. - but there's plenty of information out there.

It's well worth reading the MegaManual from Bowling and Grippo (the originators of the MS) - it goes into great detail about the principles and practicalities of DIY EFI. You can probably skip the "assembly" section until you have it on the bench in front of you though.

www.megasquirt.info/

The MS Extra site has a lot of information covering different options for reading engine speed and producing sparks - after all, adding ignition control is one of the main reasons it exists:

www.msextra.com/doc/index.html

Megajolt is basically an offshoot project - a stripped-down megasquirt intended to only provide ignition control. It's much less 'open', so there are fewer options: it's designed to be used with the Ford EDIS setup and basically needs a few wires and a bit of pipe to install it - but it can't do fuel.

I'm not aware of any projects on here using it yet, but I do have a V2.2 MSI to control the fuel (via Yamaha R6 TBs) and sparks (via EDIS) for the hairy engine I'll be building for my Clan. Eventually.

*In years past, the MS Extra code had various silly long names such as "Megasquirt'n'spark Extra." You might still find information under those headings, but TBH all you need to know is in the 2 websites above.

Thanks very much, very useful


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So, if I was to install mega jolt onto my k10 micra (cbr600 bike carbs and turbo) what would I need?

Ford edis4 ..........and,.....?




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In your experience, is this worth buying?

Will do, thanks for input chaps. It all helps.

You could buy a scrap value saab turbo (with Trionic T5.5 engine management) , strip all the bits you need , sell on the rest as scrap (for the same as you paid for it) and end up with a very, very good, mappable turbo engine management system for little to no cash.

Sounds good, little bit out of my comfort zone tho as I really wouldn't know where to look/start