I'm just collecting the bits to convert from twin 40s to GSXR600 throttle bodies. I already have Megajolt running with EDIS and am getting increasingly confused by the choices available for MS. I have been looking at Microsquirt and cant work out whether it will suit EDIS or not. I won't be using MAP so not having on board MAP isn't an issue. What is the best option for me?

Also since the car will not be used for anything other than competition I presume 'closed loop' running is irrelevant but do I still need a lamba sensor and if so wideband?

Finally my plan is to fit my current Facet pump at the tank end and feed a Golf Mk2 GTI combined pump/swirl pot/filter unit. Will this work and should the Golf pump be fitted low down - ie under the car?

Welcome to the Forum. Essentially MS2 and Microsquirt are the same. Microsquirt was designed for Motorcycles and snowmobiles but can be used for car engines too.

The main difference between the two are the case, Microsquirt doesn't have a built in MAP and the Microsquirt has twin spark output.

I deliberated between the two for a while and decided to go with the MS2 V3, because it can be readily customised for any particular set up and I decided I wanted to have a go at building it myself which turned out to be quite straightforward.

I configured mine to operate a waisted spark set up without EDIS, I decided that EDIS was just another point of failure as most are 25-30 years old.

Megasquirt will run an engine without Lambda.

Unfortunately don't know the Golf pump, but essentially you have low pressure lift pump to swirl pot to high pressure circulating pump-does the golf pump regulate pressure and have a return to the tank, if it doesn't you may need a return fuel line and pressure regulator. Someone on here will answer in due course.

If you stick with EDIS then you can run MS1.
This is the cheapest option.
The downside is that you won't be able to do anything clever with the spark (i.e. no spark cut for RPM limit, or for other functions), although you can advance and retard and all that stuff to control ignition timing.


If you plan to drop the EDIS and still want to control ignition, then you could run MS1. MS2 is just a lot better and not that much more expensive. The benefits are complex and sometimes subtle, but the fundamental facts are that MS1 is on the limit when driving sparks and fuel but just about gets away with it, whereas the chip in MS2 is much faster and so there are loads of things that make the whole experience better in terms of usability (things like trigger logging, non-standard sensors, debugging problems, control of different things, different trigger wheels, acceleration enrichment and just general more precision and accuracy, written in C rather than assembler making DIY mods easier).


Microsquirt is a better packaged version of MS2. The benefit of microsquirt is that the unit and connectors are weatherproofed and the package is smaller. The downside is that you don't really have the flexibility to monkey around with the main circuitboard like you do with MS.

Finally, MS1 can be upgraded to MS2 with a daughter board upgrade (no expensive), you would have to retune because (as far as I am aware) there is no conversion software to do that job and the tables are slightly different.


You can definitely run without a lambda sensor. If you are not road legal then that makes some sense as you will have to tune on a rolling road. For me lambda sensor has allowed me to road tune, which is good if you are going to continually modify the engine.
One cheap option is a narrowband lambda, these don't need expensive drive circuitry and give you a clue to the mixture (often helpful when you aren't sure and the engine isn't running right), you will want to get a threaded insert in your exhaust anyway (I would have thought) even if it is just when doing the rolling road thing.

Matt

e went ahead and took the hardwork out of it, and built the V4. Its essentially an MS2 with all the features, better protection, and proper support, which may be a better option for you if you would like to get up and running with minimum fuss.

Give us a call and we can advise either way, but it depends how 'dirty' you want to get your hands, as to which ECU would be best suited for you..

Cheers
Matt

Thanks for the replies.

It looks like I may be best off going for Megasquirt 2 but I assume I need to specify EDIS when I order or is it easy to programme any MS2 for this setup?

I presume the relay board is a sensible addition and is required for the injectors and high pressure pump?

On the ignition side will MS2 allow me to have hard and/or soft cur rev limiters as per Megajolt?

I had been looking at buying secondhand with Stim and relay board but do I need EDIS specific set up as per my first question above?

Regards

Chris

Why nnot ditch EDIS and run VR and coil drivers??

Also, relay board is a big waste of money and time...