Megasquirt.............
Turbo Mini Forums

What do I need to get???

I see a few peeps on here are running with siamese code, what do I need to get other than the MS2 V3?? Ive built one before, but its passed on since and I think Robert has it now?!?!?! (on here)

Engine it will be going on is a 998 bored to 1043, M45 SC and blowing through an intercooler, then MPi manifold with just 2 injectors (prob not the original ones though)

Schrödinger's cat - so which one am I ???

Using the siamese code with 2 injectors doesn't require much more than what you'd need for another 4 cylinder with a cam sensor. So, as Rod says, you need the 2nd trigger modification and the needed modifications to fire the coils (which depends on which coils you use and how many: 2 or 4).

The main additional cost will come from the 2 WBO2 sensors you should get to correctly set the injection timing. I guess you could do it with a single sensor that you'd move from the inner to the outer cylinders but that would be a pain and would be difficult to have tests done in the same conditions.

But do have a look at the different posts on the subject here and you should have a pretty good idea.

Jean

http://www.jbperf.com/

Could I use the fuel pump lobe as the cam sensor??? Obviously Ill have to have it machined like the MPi one yes???

2WBO2? Can you not use a single one located where all the cylinders meet or does this not give as good feed back to the MS??

That will be me doing a search on here at lunchtime then! Cheers for the starters guys :)

You could use the pump lobe provided you don't need that hole for anything else - on a turbo install it is usually used for the oil return. The other issue is I think the MPI setup used a VR sensor in the split lobe.
I'm not 100% certain but I think so.... (you will need to check). If so the modification to the MS for the second trigger is more complex - you will need to build (or buy) additional VR conditioning circuitry as the VR circuitry inside the MS will already be used by your crank 36:1 wheel.

Paul and I have made a "digital" input (Paul used a Hall switch and I used an optical switch) for the phase sense and there is "spare" circuitry already in the MS to accept this.

The point about two WBO2s is pretty fundamental to the siamese code - the whole point of the code is to allow different injection pulse widths and timings between the inner and outer cylinders to get the AFRs correct on them individually - not just get the average right.

So during setting up at least, you need to be able to monitor inners and outers seperately.

Schrödinger's cat - so which one am I ???

You can convert a dizzy into a cam sensor. I did that for my B, made a 1-slotted wheel to work with the Crane/Allison opto sensor that was already in the dizzy. Then use the Hall/Opto input on the Megasquirt for the cam signal, and the VR sensor input for the crank signal.

So wheres the best place to get a MS in the Uk then??

My last one I ordered as a kit from the US, easy to build too so will go for a kit again!

If you want a kit, the DIYautotune in US would be your best bet.

ExtraEFI.co.uk does built units in the UK.

You will need at least an MS2, plus the cam sensor input.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

On the subject of widebands- AEM's can now be got for £140-ish in the USA. I bought 2 back with me last week, one for the DON, and another for the MOP.