Megasquirt Idiots Guide and Brainstorming Thread

[OlberJ]

Right, well it's definitely something i want to get a 3VZ working on as it could path the way for us homebuilders (read cheapskates) to get some mapping onto these beasties.

So, in the interests of us all learning, i'll ask the stupid questions (am good at that).

1) Megasquirt, what does it do?

The way i understand it, in basic form, the MS ECU controls the amount of fuel the injectors lob into the engine at any given rate and when the spark is fired. That way you can optimise you're engines performance. Is this right?

2) How does the kit come? Do you have to build the circuit boards for the ECU? Do the circuit boards come ready built, with a general layout and you adapt your wiring to suit?

3) What can the latest Megasquirt control? Fuel, ignition...?

4) What does it cost for the kit?

5) What can Megasquirt NOT do that other ECU's can?

6) What do you need to fabricate to make the Megasquirt work with your engine? Trigger wheels etc.

7) How do you control the ECU in the first place? A serial connector and programme on your laptop?


I'll think of more questions but i'd like to keep this all in one thread and see about taking it forward, using people's input and finally mapping a 3VZ on this piece of bargain brutalness.

I know some of you are about to do/doing this right now so if you don't mind sharing, that'd be ace.


Cheers,
Olie

[Marksman]

A very good thread OlberJ :thumbsup:

The MS can be bought as a bag of bits or a fully configured and built up system. I think Alan (experienced solderer with a understanding of electronics) said it took him about ten hours to build the unit. However even minor mistakes can be hugely time consuming to track down. Hardware rigs and diagnostic software to test a newly built MS is available though. I believe when his 4agze is done a spare unit will be used to experiment on our own 3sgte's and 3vzfe's so there is a potential for a pre-built, base map equipped, self tuning product from Alan and possibly in partnership with SWAT. It's all early days and I don't want to speak for the guy as that's his business not mine...

There are a whole host of features available which I'm sure Alan will expand on.

Exiting times,

Owen.

[OlberJ]

I guess a base mapped ready built unit would be perfect but i wanna get in and about it myself, my patience is thin :mrgreen:

Am proper interested to see what we can do with it, and if it goes tits skywards then not a lot lost but a whole heap of info learned.

[Marksman]

Amen to that.

Owen.

[biteme]

For those who want to use a carPC, they have a nice digital dash for it called MegaTunix
http://megatunix.sourceforge.net/

[AlunJ]

Heya Olie, sorry just spotted yer post on my thread.

I'll chip in with what I already know about the MS, but remember that there's still a fair bit I'm learning as I go along. I had to write my own air / fuel tuning software this afternoon due to probs with one of the standard MS programs, but I think I'm getting there slowly.

1 - what it does

Megasquirt is a fully programmable fuel and ignition control computer, capable of acting as either a full standalone ecu or as a piggyback unit controlling additional injectors & spark.

2 - the kit

The kit comes with a pre-made PCB and a lot of well-labelled bags of component parts (quality of labelling may vary depending on who you buy your kit from). Optional configurations and modifications require additional components to be purchased and fitted.
Pre-built units can be purchased, but double check that any modifications that have been carried out by the builder have been done correctly. Many of the issues I've had running the original toyota ignition and programmable outputs have been traced to faults in the purchased pre-built unit. I lost two days work down to the SC engagement failing until I found a 10k resistor in place of a 1k in the programmable output circuit (on both output circuits).

3 - what does it control

This depends on megasquirt version and the code you are using. Some ECU codes are optimised for specific applications, a general overview is provided below. The code I'm using is the megasquirt and spark extra variant.
There is a version with upgraded processor and hardware (called MegaSquirt II) that expands on these capabilities.

MAP sensor replacing AFM (stock sensor ok to 20psi boost, upgradable to 44psi w hardware mod)
2 Fuel maps (144 manifold pressure / rpm points per map)
2 ignition maps (as above)
2 wideband AFR maps (96 point per map, closed loop control)
Ability (depending on hardware configuration) to control up to 12 cylinders
Support multiple injector banks, high + low impedance injectors and injector staging (via rpm, throttle position, boost etc)
A varying number of programmable outputs. These can be configured to activate on any engine parameter (eg using throttle position to control a 4agze SC clutch or RPM and manifold pressure to control TVIS)
Programmable rev limiter and type (spark cut, fuel cut, ignition retard)
Multiple ignition systems supported, from stock toyota units to wasted spark coilpacks etc.
Launch control & flatshift (via clutch switch input) with integrated nitrous control (cuts nitrous on launch / shift with programmable delays)
Option for mappable boost control (36 point map throttle position vs rpm)
Tacho output (not functional on my 4age dash yet, but there are apparently ways to get it working)
Shift light
Uses stock temperature sensors
Datalogging to laptop
ISCV control (still working this one out)
Cold start control (so you can ditch the cold start injector)
Knock sensor input
(think it does a few other things, will edit tomorrow)

4 - what it costs

my built unit cost £330 (and many hours tracing mistakes), my kit form cost approx £230 and a good 8-10 hours of building and checking. Extra costs can be incurred if ordering parts for upgrades (additional ignition coil controllers for wasted spark etc).

5 - what can't it do

traction control isn't fully integrated yet
I dont think it can yet control variable PWM systems used in some variable valve timing systems (edit: might be possible if you did something clever with the second fuel injector map etc, might be worth looking into)
it doesn't come with a huge number of additional inputs and outputs, there is scope for adding some additional inputs (EGT sensors, vehicle speed sensors), but these require additional modifications and are not always 100% supported depending on software versions.
Will probably come up with more to add as people ask

6 - fabrication

This depends very much on how the megasquirt is configured. Some engines require no fabrication at all and can be run as a direct plugin (research into the 3sgte & v6 are going on at the mo as to whether a zero-fabrication setup can be created).
My ford coilpack based configuration required the purchasing of a trigger wheel to mount on the crankshaft (due to the removal of the dizzy and therefore ignition system trigger), and a bracket for a ford VR sensor. Custom leads were made up from ford escort leads (from the scrapyard just for the end connectors) and a set of magnecor 4AGZE leads.
Anyone wishing to use a screw-in wideband sensor on a standard toyota exhaust manifold without permanently welding in a boss (at least on the sc, turbo or v6) will need to fabricate a sensor adapter as the stock toyota oxygen sensors all seem to use a flanged fitting.

7 - controlling the thing

laptop with a serial cable, or a USB to serial adapter. Bluetooth is also possible using a plugin dongle, megasquirt boards provide a power supply for this on a pin of the serial port.
MegaTunix and MegaTune are the two main programs to look at.
VexMe apparently lets you tune the fuel map using datalogs, but I've had issues with it and have made my own excel based version.

That's about all I can think of for now, will edit this tomorrow and add more info about the above and go into some details when I'm more awake :rofl:


NOTES: Things you NEED during building and setup.

DECENT usb to serial cable, not some unbranded crap that'll cause you loads of problems (or old cheap lappy with serial port).
Fuel pressure gauge (which seem to be harder to buy than unicorn horns around here), so you know you're getting correct fuel delivery.
Oscilloscope. Even if you have to go and beg / borrow / steal one.

[OlberJ]

That's fantastic Alun, cheers.

Any pictures of the component parts cos that's where am failing to understand the level of "building" that needs done.

[Paff]

here ya go Olber....

From empty board and bags of small components.....
http://www.woodsport.org/forum/images/recovered/2008/08/258.jpg

to
http://www.hainesengineering.com/rhaines/corvair_080203c_ms.jpg

someones thread on the build below (includes the simulator construction)
http://www.hainesengineering.com/rhaines/corvairms.htm

[OlberJ]

Brilliant Paff, so you get the board and then fit the biuts to suit.

Makes much more sense to me now and it wouldn't be hugely outside my capabilities then. Would just take a long time to work it all out.

Right, that's the basics out of the road.

[Limeymk1]

Ollie you can get ready built ones from several sources if you don't want to DIY.

If I was to get one from any one it'd be this chap (fellow Mk1 owner).

http://www.diyautotune.com/products.htm

[Goldy]

I may be able to give you a hand building if you want... i've no megasquirt knowlege but I do work in electronics...

[OlberJ]

Aye that would be ace Goldy, have heard you're pretty handy with the soldering iron.

[OlberJ]

Ollie you can get ready built ones from several sources if you don't want to DIY.

If I was to get one from any one it'd be this chap (fellow Mk1 owner).

http://www.diyautotune.com/products.htm

That looks good prices too.

[TbarTurbo]

I remember reading that 1MZ engine uses a 60-2 flywheel trigger... if thats the case i think V3 boards work with that out the box, its the same as pugeots, and i know they dont need the ford edis system.

I guess this depends on the trigger being on the v6 engine or the mk2 flywheel...

megatunix rocks BTW , had it for ages even though i have no MS hardware :(

[OlberJ]

Jus building a 1MZ at work and noticed the trigger wheel right there, already setup. It's jus behind the crank pulley.

Megasquirt would be pretty much plug and play for you 1MZ guys.

[TbarTurbo]

Can you utilise the 1mz pulley on the 3vz ?

[supersi]

Megasquirt can utilise any tooth wheel IIRC. i.e. you just need to tell it in the software what you're using. Well that is with the V3 board anyway.

[Stu]

nice thread guys

has anyone on here megasquirted a 3s-GTE ?

very interested in the idea

how do you get on with mapping these?

[robwsurf]

a few people have if you look on the megasquirt forum dont think anyone has on here yet

[AlunJ]

has anyone on here megasquirted a 3s-GTE ?
Not yet, but have been asked to do one in the coming couple of month. The install should be the same as the 4age though: blanking off the dizzy, fitting a trigger wheel and coilpack then going from there. Tuning's done with a wideband O2 sensor.

1MZ would need some mods to run MS as a plugin option I think, MS can't use a 60-2 trigger without a secondary trigger indicating when no1 cylinder is at TDC (a 60-2 with the missing teeth 180 degrees apart just tells the ECU that A cylinder is at TDC). A second VR sensor input circuit would need to be constructed and I believe the signal from one of the camshaft position sensors would give ya what you need.

[OlberJ]

I think the 1MZ has 2 teeth missing together, not opposite each other.

[Barronmr]

Hey guys,

Im pretty sure Im going to run megasquirt in my mk1 1st build.

I've noticed the place linked to, to buy them from is in the states, but i don't fancy getting hit for tax's does anyone have experience of any uk suppliers?

ta.

[Marksman]

Alun and Podge have both ordered from the UK, and in each case service was dire. Not sure who they ordered through though, so there are certainly places worth avoiding. Hopefully there are ones who are good too!

Owen.

[Barronmr]

Alun and Podge have both ordered from the UK, and in each case service was dire. Not sure who they ordered through though, so there are certainly places worth avoiding. Hopefully there are ones who are good too!

Owen.

I've been looking at 2 suppliers, one through ebay and another found via google.

ebay
www.mtechautomotive.co.uk

google
http://www.extraefi.co.uk/

Don't suppose Alun and podge could pop on and let me know if either of those are the two?

ta

[Marksman]

Might be worth your while sending them a PM as they're not on the forum very often.

Owen.

[Barronmr]

Will do, which forums do they frequent the most?

[Marksman]

This one I think, just not enough hours in the day to be around much.

O.S.

[AlunJ]

extraefi.co.uk - Phil Ringwood (the guy I bought mine off)....
sold me a mis-built megasquirt board complete with incorrect programmable output hardware (incorrect resistor sizes causing relays to not pull full 12v), completely arsed up toyota VAST modification (it never worked, he later admitted that although he wrote the instructions for the modification he'd never performed it), miswired idle control valve wiring (burnt a trace outta the board) and didn't equip the board with the 2 spark outputs I paid for (only came set up for one). Oh, and it took 4 months to turn up.

The board ended up being completely rebuilt to run on a ford EDIS system instead, as this bypasses the areas of the ECU where his mistakes occured. Megasquirt was restored to stock harware configuration, and all modifications re-done by myself.

Mtech automotove should not be selling megasquirts, they've been banned by developers from selling MS hardware due to the poor quality of their work (link from MS forums).
http://www.msextra.com/viewtopic.php?f=108&t=27075

My kit form one came from DIYAutotune.com - again, based in the US but faster and more reliable than the UK distrubutors / manufacturers. Came with everything needed, nicely labelled and easy(ish) to build, though you may need to visit yer local maplins for a few bits and pieces for mods (bag of assorted resistors would be handy). Import duty will suck though, so don't bother paying for the fast delivery. Mine got to the UK in 4 days (use the parcel tracking though, as customs wont tell you for a week if it arrives where the DHL tracking will let ya know when it's at the depot to go and collect).