First time squirter :) Megasquirt Info Thread
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Im about to order some goodies from Diyautotune to build a Megasquirt V3 (MS from now on). Basically i want to try and run everything from it for my TT V6 build . So including boost control, spark cut etc. Ive heard from some people that the big boy ecu's like the hydra and link are more suited but they just aren't brutal enough :icon_biggrin: Ive got some soldering experience, but mostly connectors and specific parts for weighing bridges, not a lot of pcb stuff, so that will be a nice challenge.
Since this is my first experience with ECU's in general, i thought it might be a good idea to put everything on here, and bomb the (MS) ecu guys (yes im talking to you alunj :blabla:) with questions. In the end i will make a solid write up so everyone running a 3VZ-FE (with or without FI) can have a go with a proper manual. Ive linked most of the products and terms used, so people interested can look up the meaning of certain words immediately. This is mostly going to be about 3VZ-FE, because that is what i'm using. But if anyone has something to add to the list, that is specific to other V6 engines (1MZ/2GR) please do! :thumbsup:
General info links:
http://www.diyautotune.com/faq/faq.htm
www.msextra.com
3VZ-FE with MS (Edis) build on mr2oc
3VZ-FE with MS build on twobrutal
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-First the shopping list, this is what you basically need for a V6:
*Megasquirt 3 with pcb 3.0, unassembled kit --> Specs and features ($373.00)
This is the UNassembled version, if you don't trust you're soldering skills get the assembled version. To see what involved i've found a nice thread here. They do come with a very good assembly manual.
*JimStim v1.5 MegaSquirt Stimulator w/ Wheel Simulator -Unassembl ($59.00)
Even the simulator can be scrapped, but i would very much advice against it. With the simulator you can program the MS and test it before if even gets close to you're car. You don't want to clown around learning the system with you're engine on the line
*Innovate Standalone Gauge Kit w LC-1 & XD-16 - 3781 ($299.00)
This is a very popular wideband O2 air/fuel ratio meter, you don't need this if you're not planning on doing any tuning yourself. If you take it to a dyno and let a professional tuner do the work, he has his own anyway. But then again, people that do that probably wont buy a MS
There are some parts that make it easier, for example:
12' MegaSquirt Wiring Harness (MS1 / MS2 / MS3 Ready) ($65.00)
I'm not bothering with extras, i've got all the cable and db37 connectors i need at work, and i want to create a new wiring harness anyway.
There are however some extra parts i need, since im using COP and FI (more on this further down):
MegaSquirt-III MS3X Expansion Card ($90,-)
Like the description says, this is an expansion board to the MS. This will add functions like boost control and all the sequential and extra I/O capability of the MS3 processor.
*PCBv3 -- PWM IAC Valve Control (TIP120) 'Mod-Kit' ($7.50)
Not sure if this is needed. The 3VZ-FE im using has a IAC valve, but when using the MS3X expansion board this function might already be on it, still waiting to hear from Diyautotune on this subject.
*EBC Electronic Boost Control Solenoid Kit ($39.00)
This is used to control the pressure going to the wastegate actuator on the turbo, basically controlling the amount of boost that is fed to the intake manifold. You can do this manually by plumbing a line from the intake to the actuator but this has several disadvantages. More info here (might need 2 of these, , but first im trying to split this up using a T piece, so i can control 2 actuators with one solenoid)
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-Ignition,there are a couple of ways to do this.
1: Run the standard ignition, and use the wheel inside the distributor + VR sensor
This probably the easiest en quickest method, no fabrication work needed etc. But also more crude. Wasted spark and COP have long since superseded this ignition type. With this type of setup you cant use advanced functions like launch control or flat shifting, as you can't mess around with the spark timing.
2: Wasted spark, the spark plugs fire in pairs even though one is on its compression stroke and one is on its exhaust stroke. The extra spark on the exhaust stroke has no effect and is thus "wasted". (Ford Edis-6 ignition uses this method), this means installing a 36-1 trigger wheel on the crank + VR sensor but gives a better controllable spark, and gets rid of the distributor all together. You still need plug wires though.
3: COP (Coil on plug), this means you are running 1 coil per plug, controlled directly by the ecu. You will need two signals for this, a crank signal + a cam signal. Both can be found in the distributor or you can use 2 different VR-sensors. Removes not only the distributor (unless you're using the signal from this off course) but also the plug wires. So no more problems with crappy wires or worn out distributor caps. You need six outputs so this method can only be achieved by using the MS3X Expansion board.
4: COP + Waisted spark. This is a bit of both, you can still use 1 coil per plug, but you fire them in pairs meaning you will only use 3 outputs on the MS3X, making for a simpler installation and a cleaner look. You could even run this without the MS3X expansion board, since you only need 3 outputs, but this means you will loose those outputs for other options like nitrous etc.
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COP Parts list:
Ford Edis 6: You will need the 6 coils + igniter, and the 36-1 trigger wheel + VR-sensor.
COD/Wasted spark: You can get new coils and igniters from diyautotune, which are directly controllable by the MS. Or you can use other coils that are supported right now by the MS, like the US LS1/2 coils, or the Mazda RX8's.
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The LS style coils are of a "coil near plug" design, they are also logic level. They are fairly easy to obtain used (in the USA) and are available new from OEM or aftermarket. The truck coil (mostly listed as LS2) gives the most powerful spark and is easily identified by the heatsink. There have been some measurements done and it seems the LS1 coils give 40ma, while the LS2 (truck) coils give a whopping 120ma. Dont think however that the LS1 coils aren't suitable, they have a very short dwell (charge time), and are powerful enough to drive almost anything.
There are many different coil on plug coils used by the OEMs. Some are logic level, some require high current drivers. If a coil has two wires it is certainly high current. If a coil has three or four wires it is almost certainly logic level. Mazda rotary coils have integral ignitors and can also be directly connected to the MS3X logic output.
Another option is to use the oil pump from the 5vzfe, this has a 36-2 toothed wheel and a provision for the VR sensor. You can use an ignitor from efisource.com to power the 5vzfe coils. This makes for a clean and relatively cheap solution, keep in mind though that this system does not have build in igniters, so you still have coil->wire->igniter.
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-Injectors:
Stock injectors for the 3VZ-FE are 200cc. The 1MZ has slightly bigger injectors, 270cc.
The best upgrade for the 3VZ-FE are the supra injectors: '90 7M-GTE [part nr:23250 42010] - 440 cc's @ 43.5psi 2.7ohms, low impedance.
The MS can handle both high and low impedance injectors. To use the low impedance injectors you need to limit the current. This can be done by using ballast resistors, or using the MS's pulse width modulation.
MS pwm settings for low impedance injectors:
PWM Current Limit to 30% in most cases (all V3 main board with active flyback installed)
PWM Current Limit to 75% if and only if you have you impedance injectors and have NOT installed: the active flyback circuit on a V3 main board
Both these methods aren't ideal however. Limiting the current to 75% has the effect of lowering the injector maximum flow rate at the top end. I would imagine only having 30% of total saturation would limit the speed of the injectors ability to open. The ideal solution is to use the Peak&hold injector driver board, which uses a high current short peak burst to open the injector quickly, and a small holding current to keep it open, thereby using the maximum injector flow rate.
Here we have the original 3VZ-FE and the 7M-GTE next to each other: picture link. If you want to try other Toyota injectors, Paul has provided us with the big list of injectors, and their respective specifications here.
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-Sensors
Im using the LC1 (see shopping list) as a wideband, so i can keep an eye on the AF ratio, and do some road tuning. The MS has a 2.5Bar MAP sensor, which is around 36PSI. Keep in mind that this is 2.5 bar absolute reading, the first bar of that is used for NA operation (the range under vacuum). So the sensor's range is from 1 bar vacuum to 1.5 bar (20 or so psi) boost. The MS can run the engine solely using the MAP sensor, which means you can remove the AFM!
I will not even reach 10PSI with my current setup so this is more then adequate. (If you want to go very mental, you can upgrade to a 4Bar sensor). Most of the other sensors like temperature and oil pressure will work on the MS so no need to change them.
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Originally Posted by AlunJ
