Megasquirt
- this is very outdated information and should only be used as a guide to fit a newer ECU or repair***
The following article follows the installation of a Megasquirt 1 ECU onto a RB30e. Running a
Megasquirt 2 ECU should be very similar to setup, so it would be up to you to weigh up the pro's
and con's of each to determine which is best for you.
You will need to read most, if not all of the information in the official megasquirt site as well as consult the megasquirt forum. This is
an invaluable resource. Below are links of where you can purchase megasquirt hardware. In
Australia you will most probably have to order from a US site. I bought all of mine from
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Please note this article under construction and not complete.
Please doublecheck all information you use to ensure it is correct.
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My apologies for the formatting, I will endeavour to make it more readable asap.
What to buy
I bought, built and installed a MS1 v2.2 board and loaded it with "Megsquirt and spark extra"
firmware which supplies the spark output via the Fast idle pin on the MS.
Currently I have had it running a half decent tune using on road tuning using Megatune, the WB02
Linear input and MSLVV (log viewer).
The v2.2 board does not have the improved flyback circuits (for low impedance injectors like on
RB30e). I have successfully run RB30E and now RB30E+T for about 6 months but it is not driven
every day. There is potential for the flyback circuit to draw too much current and die so I
highly recommend the improved flyback circuit of MS1 v3.0 board.
Megasquirt v3 kit
OR
megasquirt 2 kit - if you wish to try Megasquirt 2
MSnS Extra daughter board - I ran successfully for 6 months without the MSnS (Megasquirt'n'Spark)
Extra firmware without the need for the MSnS Extra daughter board but have now ordered it because
it neatly combines the extra outputs (boost control, launch control, water spray etc etc) in one
board.
Wiring Loom:
I am running the original loom and ran extra wiring where I needed (for air temp sensor, TPS etc)
I got a old ECU and desoldered the plugs out so I could use existing loom and plugs. One issue I
have had is that the pins fatigue and break easily when you move the ecu around, and unplug it
etc.
One Idea i had was to make a mini pcb to mount the plugs on. You could put this in a little jiffy
box and it should be fairly robust and look quite neat.
Basic explination of the wiring:
== Air temp - VN commodore air temp sensor - about $32 new from Holden or wrecker. You will need the
plug (from wrecker most likely)
== Coolant temp - using existing temp sensor. Can be calibrated, see below.
== TPS signal - use XF Tb with POT TPS switch. It will run fine without TPS but If no TPS then
needs to be earthed via 1k ohm resistor
== 02 sensor - Using WBO2, wired with a old lan cable, solid blue pin 23, blue/white to ground.
Otherwise pin 24
== CAS sensor - Using original CAS signal 1 (pin 17 with 1k pull up resistor to +12v pin 34)
== 5v TPS - wired to TB using existing loom hopefully TODO
== Power - Wired to Pin 34
== Spark signal - to Pin 5 with 1k pull up resistor to +12 pin 34
== Injector 1 output to pin 101, 102, 103
== Injector 2 output to pin 104, 105, 106
== Fuel pump, needs to be rewired with a relay using a 20A fuse straight from the battery. Then pin
37 of the Megasquirt grounds the relay to activate it.
Fuel pump:
TODO: Describe wiring pins for fuel pump and relay setup.
CAS/AFM relay rewiring:
AFM/CAS green power relay, behind the original ECU, is activated by the original ECU earthing pin
6 when it powers on. This will need to be rewired so that it is activated by +12v from pin 34
(igntion on). Pin 26 of original ECU loom is the AFM/CAS ground. Earth this. TO CHECK
TPS wiring:
Earth TPS pin xx via 1kohm resistor if not using a TPS. If you do not do this you may notice the
light "Flood Clear" in Megatune is on. This means the injectors are not firing because the ECU
engages Flood clear mode when full throttle while cranking.
CAS timing settings:
You should be able to leave the distributor in the current position. Then using a timing light modify the timing offset with the Megatune software so it brings the timing to the correct position. I will add more information on this later.
Calibrate the coolant temp sensor
TODO
Initial software settings.
TODO
Tuning:
I tuned so far on road using a WBO2 wideband sensor, Megatune and MSLVV (MegaSquirt Log Visual Viewer).
Its around $200 for the DIY WBO2 kit and you will need to buy the wideband o2 sensor as well.
Sample RB30e and ET tunes
Upload here
Links:
General: official megasquirt site megasquirt forum WBO2 wideband sensor Megasquirt'n'spark extra
Megasquirt hardware:
Glens Garage
DIY Auto Tune
RS Autosport