As I have been promising this is the complete guide to megasquirting your m50. Lets begin
For the other e34s see http://forums.bimmerforums.com/forum...d.php?t=856880
Next up will be the m60 if there is any interest
First you must gather all the tools and supplies
From your local radio shack
Soldering Iron
.030 Rosin Solder
Solder Wick (for your **** ups)
Male and Female DB9s solder cup style
Various colors of 20g stranded wire
A few feet of 2 core (minimum) shielded wire
Maybe a “third hand” or a nice girlfriend
Assorted ¼ watt resistors (330, 1k, 2.2k, 4.7k, 10k, etc…)
Two potentiometers (10k and 100k)
Some 1n4001 diodes
A package of npn type transistors (2n2222a for example)
If you have vanos you need a relay too
From DIYAutotune
MS 2 v3 board with the black case (silver is for losers)
External USB adapter
Innovative LC-1
From Glensgarage
The 3 wire PWM idle valve board
5 extra vb921 ignition drivers
From your local hardware store
A few nuts and bolts for securing the MS and grounding points
1/8” electrical shrink wrap tubes
Some sort of electrical insulation (hot glue, caulk, etc..)
Crimp style ring connectors (yellow)
Digital multimeter
Grinder/dremel tool
Screw driver set
You will obviously need an ECU (preferably junked) but that don’t happen often
Because of space constraints I have built mine externally unlike the motronic 1 units. If you got MS1 and are a very confident builder, an in box design could be done.
First we are going to strip the ECU of its brains
Remove the outer cover and all of the screws on the bottom. The boards should come free of the aluminum housing. Where the screws go through the board to the connector there will be a small metal ring. Grind it off the surface but don’t go too deep, we want to save the threads. Clip the leads on the other side leaving about ¼ inch still on the connector. Just remember the longer the pins are, the more brittle and easily bent they become. The connector should come free from the board. This must be done to both sides but don’t put the top piece back in right away. It is easier to get to the middle pins without the top pins in yet.
Next we will build the Megasquirt
-not so intimidating, is it.
Follow the build instructions from the megamanual with a few exceptions
-You do not need to install the coil driven tach signal, or the hall circuit so skip step 50. (on some of the later I6s a hall sensor was used but to my knowledge not on the e34)
-on step 52, jumper VRIN in to TACHSELECT and TSEL to VROUTINV
-Skip step 65, save the vb921 though
-Also in the proto area, you must build the tach out circuit. Use the diagram from the MS1extra manual and send the signal wire to the IAC1A output near the DB37
From the top side of R26,27,28 run a wire from each to the other 3 IAC ports by the db37 labled SPR. SPR1 is Spark A, 2 is B, 3 is C
The Megasquirt is now complete. Next we will build the harness adapter.
If you want you can buy the pre made harness but I think it could be a little hard to stuff it through the hole in the fire wall.
If you are building your own (I recommend it) you will need about 24 wires cut about 2ft. in length and the shielded wire. Solder the wires to the db37 first. The 2 core shielded wire should be grounded on this end. I use pin 1 and 2 for the VR shield ground and sensor ground and the second wire connects to pin 5. It is important to remember which one is which. This is probably the most important wire of the bunch. . You need to use all of the bottom row (20-37) except for the IGN port (Pin 36) and two if the ports (29 & 31). On the top row almost all of the ports are grounds (except for 3-6). You don’t need to use all of them but at least 5 should be used, they will be combined to form the common ground. Pin 3-5 are spare outputs and will be used for spark. Pin 3 is A, 4 is B, 5 is C.
Orient the DB37 the way that it will be mounted in the car. The MS case won’t fit very well front to back so I mount it sideways. The harness must be twisted to one side to fit through the hole any ways. Also, I decided to mount mine on the top of my glove box so that the harness wouldn’t be moved every time I open it. Bend all of the wires in whatever way you want to mount the box. Remember though, it can’t be any wider than the hole it has to go through.
Before you solder the harness to the back of the 88pin you need to build a circuit to control the relays
These diagrams should help in the construction of the relay circuit
-The emitter connects to the ground wire
-The base connects to pin 56 with a 4.7k ohm resistor in line
-The Collector connects to pin 27
-Solder the 1n4001 (D1) diode across Pin 26 and 27 with the banded end towards 18
Secure the transistor to the case with hot glue or silicone caulk. It would be a good idea to cover the entire back side of the 88 pin connector in silicone caulk once the harness is complete. This will also help wires from accidentally breaking loose if they were not soldered very well (shit happens, plan accordingly)
Next cut another 10 or so wires about 10 in. long. These will be for combining the grounds on the stock harness. Connect one to every GND point on the 88pin and combine them all in a ring connector. Pick one of the holes (or drill your own) on the base plate and put a bolt through it. This will be your common GND.
Then we will solder the coil driver wires to the 88pin. I use 3 different colors (RED, GRN, BLK)(two of each) for the ignition component because we are firing the coils in pairs. Cyl 1 & 6 are paired on RED, 2&5 on GRN, 3&4 on BLK. Just leave these wires on the harness with about 8 inches of slack. We won’t build the IGN circuitry until later.
Cut another three wires about 10 in. for the IAC open and close. These will go the board from glensgarage. You will also need to bring out 12v from the same place the MS gets power.
For the injectors you need to combine cyl 1-3 into one bank and 4-6 into another. Cyl 1-3 get connected to the first two injector wires and 4-6 to the second pair.
The rest are fairly straight forward. Just solder the wires straight to the corresponding pin. Try to keep all of the wires going straight to the MS box as close to the 88 pin as possible. You still need room for the idle board and 6 vb921 ignition drivers.
First Number is the Motronic connector and 2nd is where it goes.
M50 NON VANOS
1- 37
2- Idle Board (ISV2)
3,4,5 Fuel Injector Pin 32,33
6 GND
12- 22
23- Coil 2
24- Coil 3
25- coil 1
26- Constant 12v- Banded end of 1n4001
27- Relay control Circuit (other end of 1n4001)
28- GND
29- Idle Board (ISV1)
31,32,33 Fuel Injector Pin 33,34
34- GND
36- GND (optional, evap purge valve)
37- GND
50- Coil 4
51- Coil 6
52- Coil 5
54- Pin 28 and idle board
55- GND
56- Switched 12v- Relay control circuit
59- TPS 5v- 26
67- VR sensor (24)
68- VR sensor (7)
70- 23
71- GND
74- Tach o (one of the IAC ports)
77- 20
78- 21
M50tu
1- Fuel Pump relay -37
2- Idle valve close (ISV2 on glens board)
3,4,5- Fuel inj 4-6 (34,35)
6- GND
7- Vanos activation (grounded via relay)
13- O2 sensor -23
14- MAF GND (optional)
15- GND
16- crank sensor - 7
23- Coil 4
24- Coil 6
25- Coil 5
26- constant 12v - banded end if 1n4001 in main relay circuit
27- Main relay CTRL - other end of 1n4001 and leg of 2n2222a
28- GND
29- Idle open (ISV1 on glens board)
31,32,33- Injectors 1-3 - (32,33)
34- GND
38- O2 relay (GND)
40- o2 GND
41- MAF signal (optional)
43- crank sensor (24)
44- GND
45- GND
47- Tach out (whatever pin you used, 25 if you followed my directions)
50- Coil 1
51- coil 2
52- Coil 3
54- +12v (28) (and glens board)
55- GND
56- Switched 12v (resistor in line with 2n2222a in relay circuit)
59- TPS 5v (26)
71- GND
73- TPS signal (22)
77- IAT (20)
78- CLT (21)
Once the main wires have been completed mount all 6 of the vb921s in a row on the right side of the case. Combine all of the dumps (when the pins are facing you, the right one, or "pin 3") to the common ground. Solder one coil pin to the middle pin (pin 2) going in order from top to bottom (spark 1 at top and 6 at bottom). Then on the left pin (pin 1) pin solder a 660 ohm resistor. On the other end of the resistor is going to be the signal wire from megasuirt. You will need combine the paired cylinders here. Combine 1 & 6 for spark A, 2 & 5 for spark B, 3 & 4 for spark C. I would also highly recommend you place a modular connector (mollex or db9) in the line to megasquirt for the spark outputs. When you flash firmware you need to unhook the coils and it would be a lot easier here than doing every coil individually. I hope this isn’t too confusing, I will get some pics up soon.
This Should help
This one was for an m52 so the coils are on the wrong side but you get the idea
Next you need to mount and wire the idle board. You need to ground it to the central ground and get a 12v feed from the same pin MS gets it. ISV1 goes to the Idle valve open pin and ISV2 is close. The signal from MS goes to FIDLE. If this sounds confusing on paper it is very obvious when the board is in front of you.
The last step is to install the relay for the VANOS solenoid. Wiring is simple and mounting will vary with the relay chosen.
Long story short, pin 7 needs to be grounded on cue. Build a relay control circuit in the proto area with the control wire coming out pin 27
Use this diagram
O2 sensor.
As stated earlier, i highly recommend th LC-1. Place it in the stock sensor location and hack off the pigtail from your old sensor. If you ever want to go back to motronic, the LC-1 can simulate a narrow band.
Wire the LC-1 straight in to the pig tail and seal it with heat shrink
Pin 1- Sensor GND- GRY
Pin 2- Signal - BLK
Pin 3- GND- White
Pin 4- 12v- White
Use an ohm meter to determine which white wire to use for power
From LC-1
BLU and WHT are both GND- combine them with a spare black wire about 4 ft long and conect them to the GND wires on the Bosch connector
RED wire is power, conect it to the 12v white wire
BRN wire is output 1 and will go to the BLK wire
BLK wire is the calibration wire. Connect about 4 ft of RED wire to it
YLW wire is output 2. It can be used for a guage or leave it there and tuck it in out of the way
The spare BLK and RED wires you attached are for the calibration button. Run them into the cabin of your car ( i ran them up through the shift boot and keep them hidden under the shifter. Connect the switch and LED to the two wires as outlined in the LC-1 manual. The Red wire on the LED connects to the RED wire you brought in. The switch wont matter. If you want you could use any led and switch you want and make a nice mounting plate for in front of the shifter for other switches and gauges. I made a plate out of wood and put my launch control, LC-1 switch and LED, and a USB port for easy access and will add things as i go. It looks very nice.
Tap into the vacuum system for your car with the T connector. The best way is to use the lines from either the FPR or the one running to the underside of the intake boot above the harness. Cut the hose and place the T in. Run the Vacuum line into the ECU box.
Now you are ready to power it up for the first time. After you have installed and configured Megatune you can download your firmware. Do not use the base codes. Go to MSExtra.com and go to the MS2 development section and download the latest beta (unless you have MS1). In the file there will be 2 .ini files. Double click both of them and follow the instructions (make sure you disconnect the coil first)
Ryan Nimick (Goathumper)
Nov 24, 2007
Me:
Last edited by Goathumper; 04-22-2008 at 04:05 PM.
More pics coming soon, and ive still got a few things to add when i get home.
Holy... crap. Nice...
E82 135i: Alpine white on black leather; ZSP; ZCW; iPod/USB
Previous Bimmers owned (from last to first): E46 M3, E34 540i/6, E30 325iS, E34 525i, E30 318i
HELLA. SICK.
Orders all placed. Bless you man .
holy bawls, the safety police already got me
They censored meeeeee.....noooooooo
Holy shit, props on that write up, that's killer. The diagrams are great too, easy to follow, Ill have to try this. That looks like my voltmeter, and weak R-Shack solder iron.
Oh and your post count is 666
Goathumper
1 question....: any motornic box or M50 specific? like I have a M50 NV that is apart right now and this is an awsome way to go....I will be contacting you off thread if that is okay with you.......
My props to you younster the write up is great....just like 'UM'
Great write-up, thanks!
1986 BMW 735i Turbo, 5-speed
2010 Mazda5
1966 Corvair Sedan
Nice. Very Nice.
Don
wow awesome writeup, but most of it flew over my head, since I have no electrical experience.
OBD2 plugs require slight dremal fixes, it took me all of 15sec to make an OBD2 motronic box fit my OBD1 harness.
Ryan, so how did you deal with securing the pins in the motronic box, how yours wires are routed, I would worry about breaking the pins off the connector. Also I think some of the wire gauge you used may be under size, do you have a chart for what you used? As well as perhaps pictures of the MS unit?
Freaking looks clean tho, good work!
-Roman
wires are 20g and 18g. When i am worried about over amperage, i double up the wires. To secure the pins, i covered the back in silicon caulk when i finished. I still have a few things like these to add.
More pictures to come, these are just the ones i already had uploaded. The rest are on my main pc back home.
I was considering a miller maf because i feel my car should be able to atleast squeel its tires..(it cant) However i have been following your thread on the ms. The MS seems like a better choice and if i read this correctly if i should turbo at a later date for more power it would be easy to recalibrate for this? I already have a laptop in the car for windows media player. But i am a technotard do you build a unit that can plug in to the harness with minimal mods. and would the car start and run (be drivable) with minimal programing?. Finaly is it reliable enough for daily use? Thank you
yes, it is daily drivable. I dont have another car and dont feel the need. The ONLY mod you need to make to your harness is to accommodate a TPS. If you want, you can run an external line for one so you wont have to make any cuts at all. The units i make are built with ease of install in mind.
The tuning is up to you but yes, it wouldn't be hard at all to accommodate for boost.
This is speaking of the m30 (not to confuse anybody)
A little update. Tis is how i ran the cables for the LC-1. I had way too much slack but you get the idea.
Everything plugs in as stock.
Damn man killer write up. How different is this for the MSI v2.2 set up?
THANKS!!!!!!!!!!!
-Chris
the board version is not so important, but i would sugest the MS2 chip and version 3 board (or 3.57, the surface mount board) The version 2 board should work but i am not familliar with it.
woo woo
power supply portion passed all tests
loopback test work also... yesss...
should be ready to test as soon as i finish up and my ecu arrives sometime this week to make a harness
up for an update ryan ?
working on it right now
Cool, I'll be glad to share pictures and any other info I have... Unfortunately, I don't get back to my ms2 and camera at school until Jan 14th.
Going to make the harness and install some goodies while I am home though.
And that pesky .msq setup... good times!
there ya go, all better
Hey Ryan, I was wondering if perhaps you had the idle settings for an M50 idle valve?
Thanks,
Roman
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