Mods To My Megasquirt

[madspikes 41 1 Cars]

Following a few thread about how much you need to learn to use the Megasquirt ecu, I thought I'd post a pic of my modified board. I've spent 2hrs tidying the wiring yesterday, as neat wiring is normally reliable... All the extra wires are mods.... and this is just the back of the main board, I have 4 other boards else where that do other things to support the ECU functionality. So thats 2hrs tidying, lets not get into how long of actually researching the mod, building the other boards etc...

 

My ecu now has...

 

* Off board signal conditioning for the crank sensor.

* Exhaust temp sensor support

* Modified to support coil packs

* Off board 3 wire idle valve support

* Tacho driver circuit

* Knock sensor input

* Offboard Map sensor

* Change cooler pump control

 

Shes quite a different beast to the standard v3.0 MS.

 

 

 

 

This shows its not easy, but can be done.

 

Mad

Edited January 16, 2011 by madspikes

[hcmini1989 16]

Nice mate is that supposed to be charge cooler pump control?.And when you say offboard do you mean running through another board ? for safety reasons?

And your a better man than me i got so pi**ed off assembling mine espeicialy when i got it all together and there was a problem with th board

 

Edit if it is a charge cooler pump do you have the schematic ?

 

cheers

Edited January 26, 2011 by pug_ham
Please just use the Addreply or fast reply instead oi quoting the previous post as requested previously.

[madspikes 41 1 Cars]

Indeed it is charge cooler pump control. This a simple bit, only a lower power transistor that controls a relay in the engine bay.

 

ma.d

[hcmini1989 16]

Ah right so do you have a temp sensor in the chargecooler system to monitor or is it controlled by inlet temps? very interesting stuff btw mate and you`ve got alot more patients than me .I could play with wiring all day but not printed cirucuit boards

[madspikes 41 1 Cars]

I quite enjoy it, when its working! But its something I can do inside where its warm to progress the 205!

 

The pump was control is rpm based, basically I turn it off at idle due to there being no flow through the rad. But could change how the MS controls the pump to inlet based temps if required.

 

Mad.

[pugpete1108 62 1 Cars]

nice

 

do you need the crank signal conditioner then?

[madspikes 41 1 Cars]

do you need the crank signal conditioner then?

 

I think as a general rule you dont, but ever since I built my MS I've always had issues with it running below 1000rpm. Sometimes I managed to get it to idle below 1000rpm but it was no way stable. There was a total back whole of running around 900rpm, this turned that I was losing crank sync, only took me around 4 years to work this out, and this use to play havoc with any idle valve I had installed. But with the crank signal conditioner (design, built and supplied by the Mad Professor - Top Bloke!) she runs a treat, idle valves work great, idle at any rpm!

 

The conditioner by-passes the original MS conditioning circuit and replaces it with a new circuit. As far as I'm concerned its total black magic, but it works and thats all I'm concerned about.

 

If you have a sync problem and have tried all the normal routes then its something to consider.

 

Mad.

[pugpete1108 62 1 Cars]

luckily mine idles pretty well at about 9-1000 rpm it does hunt a little but i think it could be a little rich anyway. it can be lumpy when cold but im not running a icv so its not supprising.

 

i would like to fit an icv at some point just wouldnt have a clue how to set one up tbh

 

i was ready your other thread and was interested in using a palm pda as a logger?

 

been doing some reading up on it and it seems though that the 3x may not be compatible with vista and i use a serial to usb lead as im using a laptop so not sure if that would be a problem or not?

Edited January 16, 2011 by pugpete1108

[madspikes 41 1 Cars]

Not a problem as I use XP! I havent had,much of chance to really play with it yet, and want to modify the code slightly as well.

 

I was going to the stepper motor idle valve route, but decided it was too much of a mare to connect into the air stream. The 3-wire works a treat, again that to another board from the mad professor and was easy to connect into the air stream.

 

Mad.

[pugpete1108 62 1 Cars]

cheers. i'll get a 3x and work it from there, if all else fails i'll use my daughters laptop which is running xp.

[madspikes 41 1 Cars]

Link to Palm code.

 

There is a thread somewhere on the MS forum that goes through all the compatible palms. I cant find it at the moment i'll post when I do.

[pugpete1108 62 1 Cars]

i have been looking at the model you have (IIIx palm) and this appears to be supported for logging and even tuning using palmtune.

 

very cool

[madspikes 41 1 Cars]

I have a palm IIIc - the 'c' being colour! Not tried the tuning software.

[pugpete1108 62 1 Cars]

Ah right I couldn't make out the last digit so thought it was a x. On the ms forum it says the IIIx is compatible and tbh I don't need a colour one anyway

[madspikes 41 1 Cars]

I've been finishing up the mods to my MS. I have now finished and tested the link to the extra box that contains the crank signal conditioner and the thermocouple amp circuit.

 

The thermocouple circuit is for logging exhaust temps, I have some probes tapped into the manifold. The circuit is basically the same as this MS Manual link The output resistor values are just slightly different, due to what resistor I had in my box! Ok, so using an AD595 is slightly over the top, giving me something like 1c to 2c resolution with a fixed cold junction reference, as all I want to for is to tell me if I'm going to melt my valves or not - eg about 900c or about 600c, prob could have got away with just using an op-amp! The EGT will now be logged with all the sensors, which then all can be reviewed together which should aid in the tuning process.

 

The circuit on the left is the conditioner, the right hand circuit is the thermocouple amp.

 

 

It attaches to the MS via a flying lead, which exits through the old MAP sensor hole.

 

 

Getting there!

 

Mad.

[pugpete1108 62 1 Cars]

looks tidy mate, nice one