A guide to adding megasquirt to your m10 (56k death)

[BoomerDJ]

This will be a write up to the best of my abilities of my megasquirt build. I decided to make this write-up because I know how much the forum loves project threads, as well as the fact that I have not seen anyone go into depth of the process of megasquirt. This will be a lot of reading with some pictures. However if you and curious as to how I did something and would like some better pics, please do not hesitate to ask. I want this to be a guide for the average e21 enthusiast like myself, with very limited time and resources. *Please keep in mind this is my opinion of what’s needed and is in no way a direct play-by-play of what to do. There will be some reading and learning to be done on your own*.

First a little history on the car and why I chose to switch to a standalone ecu

as many of you know I was running the cis system for my boost setup. It worked very well under boost, but when I was not using boost the afrs were all over the place, sometimes so lean the idle would stumble. I decided since I couldn’t afford a second car as a DD I was going to build my turbo e21 into my DD, with great fuel economy and enough power to drive with today’s factory cars. I have had several friends do megasquirt so it seems the right stand alone setup for me, along with the fact that bmw already made the efi manifold for the m10 (thank you bmw).

STEP 1
You will obviously need to start out by collecting all of the parts to start your swap. It’s a very short list of needed things, but a huge list of optional parts. I will cover what I believe are the basics and also add what I used on top of that. So off to the junkyard with tools in hand, you will need:
-early e30 318 m10 intake manifold
-the fuel rail and fuel pressure regulator together
- Depending on whether or not your going to build NA or FI you will need different injectors. If you are NA I would recommend pulling the injectors off with the intake manifold. Because I am boosted I chose to buy new ford racing 42lbs injectors off eBay for really cheap.


-you may also want to grab the 318 coolant filler neck, although I didn’t. I believe people grab it to use the stock coolant temp sensor, although I do not have the resistance values for that sensor
-A TPS, grab the one off the 318 TB or another one of your choosing, as long as it is an actual sensor and not a switch. You can test this by taking a volt meter and checking the resistance between two pins for smooth change in resistance while you turn the sensor. You will need to play around to figure out which pins are what.
-I also grabbed an m52 TB. The reason I choose the m52 was because I was using an m30 but the m52 was a bit shorter and it accepted the small TPS off the M42, which I also grabbed.
-I also grabbed a stepped IAC valve off a jeep, but I haven’t gotten that to work yet. Ill update this when I do. If you go this route 02again.com sells a very nice e30 318 manifold adapter.

-also, before you go to the yards, you will want to ask yourself what type of ignition setup your going to run. If your are going to the stock ignition setup then you do not need any more parts. However if you are going to run EDIS, then you should go find yourself a ford escort with the edis components. You will need the trigger wheel, which will need to be unpressed by a machine shop, so you’ll have to take the whole crank pulley. They usually aren’t too hard to remove. You will also need the sensor. Cut the wires are far up as possible. You always want to leave yourself some slack, especially if this is going to be your first big wiring job. You will also need the coil pack and plugs which is located on the top left of the engine I believe. Again, cut the connector to the coils with as much slack as possible. And last but not least you will need the EDIS brain. It is located on the driver’s side fender in the engine bay. I would familiarize yourself with what all of these components look like. If you decided to use edis you will need some sort of distributor plug, as you will no longer need the distributor and either buy or fabricate a sensor mount for the trigger wheel. You can buy these at 02again.com

STEP 2
You will then need to get and build your ecu. There is a step by step instruction on the megamanual website under the appropriate assembly guide. I personally like DIYautotune.com because they have pretty much everything you’ll need. I purchased this list of stuff
1 x Megasquirt-II Engine Management System w/PCB3 - Unassembled Kit
2 x 3/8" NPT Stainless Steel Weld-On Bung for IAT or CLT Sensor
4 x Fuel Injector Connector - Bosch EV1
1 x 12' Megasquirt Wiring Harness (MS1 / MS2 Ready)
1 x GM Open Element IAT Sensor with Connector
1 x GM Closed Element CLT Sensor with connector

Many people also get the Relay board, but I didn’t think it was needed. I just went to kragens and got some inline fuse holders, they don’t look terrible. Not super clean, but better than an extra 150 bucks. You could also buy an assembled megasquirt kit instead of the unassembled but it is a whole lot more expensive and not nearly as much fun as staying up till 6 in the morning slaving over a hot solder pen haha. You should also get a stim to bench test. There are several stims. I borrowed mine from a friend who had already done his setup. All of the information you will need to get headed in the right direction is on the megamanual.com. I would strongly advise poking around the manual to get a feel for everything before you dive into the project.



STEP 3
Once you have gotten all the parts to start your megasquirt it is time to look at your e21. Whenever I know I am going to be making a bunch of changes to my car I put it in a spot where it will not hinder the flow of traffic in the driveway. Some of you who have been to my house will know that I have a huge driveway. This part of my build will be slightly different from yours, but only because I was using a century intake manifold. However, start by removing everything from your engine that was used for CIS; ECU, FD/AFM, WUR, Frequency valve, Fuel lines, Air box and Intake manifold. You will also need to choose to remove the stock wiring harness or keep it in and add wires on top of it. I removed it completely and cut out the 5 or so wires that needed to stay.




STEP 4
You will then need to install everything. This part is entirely up to you. I will just put up my pics and shortly explain what I did.

STEP 5
Tune. Tune. Tune. I will supply my maps as a go along, however I am running 10 psi of boost and much larger injectors. Tuning is pretty easy. First read the configuring megasquirt section of the megamanual then move on to read the tuning part. This is where I am in my build so from here on out I will update this thread as I go

I hope this write-up helps the next average enthusiast with his megasquirt build and once again, please do not hesitate to ask questions or request pictures.




how i mounted the trigger wheel. i ground like hell and it turned out better than i thought








and how i mounted the sensor. i dont remember why we put it here but it seems to work good







stock wiring harness, i studied a wiring diagram and took out everything CIS related. all that was left was the temp sensor and the starter and alternator wires and the fuel pump relay. however i am still working on that. it seems the ms board is not turning on the pump during cranking so the car wont start unless i jumper the relay. all i did to make the relay work was wire the ground to ms and the power to the start/run bus






tried to drill and tap a stock e21 coolant neck for the gm temp sensor...fail






when wiring the VR sensor i decided to to leave myself some options since previous expirence with the ford vr sensor is that the wires tend to be backwards so i left the ability to switch them and sure enough i needed to


As the car sits now (minus a charge pipe from the intercooler to manifold)



and the car was idleing very rough and i figured it was because the stock CIS injectors stuck in so far and they were blocking the spray path of the efi injectors, so i turned them into plugs

[cheechthechi]

Great Job! Your install looks really clean and I love the way you did the edis trigger wheel mounting (I'll have to copy that). You can also use the OEM bmw coolant sensor with megasquirt, you just have to use easytherm I think and make a file for it.

[Layne]

Is that a ground clamp on your pulley while you are welding the sensor bracket? I hope not, that would be an epic fuck up. Your bearings would be ruined.

[hdriven]

Nicely done! Megasquirt is the way to go

Make sure you have a wideband for tuning, it makes everything so much easier.

[superj]

i loved building a megasquirt. i built one for my e30 but am not copmuter litarate enough to actually get it running. it worked great fro the guy who got it from me. he said he plugged it in, set up a map and it started right up. so if you guys want one cheaper, buy the kit and i'll build it up for you. i have the grounding mat, wrist strap, three irons, and a laptop to test it on. just be sure to buy the stimulator if you want me to build it so i can make sure it runs right

[EFreak]

Nice to see a DIY for megasquirt finally hit the boards. Good job!

[epmedia]

Fingers crossed on the arc welder grounding.

They are tough engines, probably (hopefully) ok.

Spin the engine by hand a few rotations before trying to start it... Robert

[BoomerDJ]

oh the engine runs and the car drives. it pulls like nothing ive ever driven before, but im going to finish tuning tomorrow. the afrs are good under boost, i just need to tune off throttle, cruise and idle

[epmedia]

oh the engine runs and the car drives. it pulls like nothing ive ever driven before, but im going to finish tuning tomorrow. the afrs are good under boost, i just need to tune off throttle, cruise and idle

Wew!

I once saw a person try to use a rotating component on a $100K + steam turbine pump as a ground with an arc welder to repair the mounting foundation. Talk about jumping quick !!!

Glad to hear your project is running nicely, Robert

[BoomerDJ]

hey josh, i was hoping this would be FAQ'ed

[jrcook320]

Nice to see a DIY for megasquirt finally hit the boards. Good job!

Read the faq much? Maybe it should be in the fuel system troublshooting/tuning section rather than engine/drivetrain.

Megasquirt/EFI

megamanual.com

DIYautotune.com FAQ page

Steve's m10 Megasquirt ITB conversion

Ken Danielson’s m10 Megasquirt conversion

02 Again – M10 Megasquirt Parts
02 Again has lots of parts for using the E30 318i intake manifold for Megasquirt including:
- TPS adapter
- EDIS VR sensor bracket
- Idle Air Control Valve adapter
- Throttle body adapter
- Distributor plug

Jester323's m20 Megasquirt Thread

Boomer's Turbo m10 Megasquirt Thread

Injector Hole Plugs

hey josh, i was hoping this would be FAQ'ed

added.

[BoomerDJ]

a question. what do people do about the tach when using MS and EDIS, i did the diode thing and the tach works but only till about 1500rpm then it cuts out

[Layne]

a question. what do people do about the tach when using MS and EDIS, i did the diode thing and the tach works but only till about 1500rpm then it cuts out

On my 320i using MegaJolt I used a .68uf capacitor inline between the MJ's square wave tach output and the tach and it worked. The same thing has not worked on my 6er using MegaSquirt. Haven't figured that one out yet. Some EDIS4 connectors have a tach output on pin #2. I believe it's the same type of square wave, so the capacitor fix should make it work as well. All modules have the tach pin, but not all connectors do.

[oldstylebimmer]

r u still running the 911 turbo fuel pump? would the stock fuel pump work?

[BoomerDJ]

On my 320i using MegaJolt I used a .68uf capacitor inline between the MJ's square wave tach output and the tach and it worked. The same thing has not worked on my 6er using MegaSquirt. Haven't figured that one out yet. Some EDIS4 connectors have a tach output on pin #2. I believe it's the same type of square wave, so the capacitor fix should make it work as well. All modules have the tach pin, but not all connectors do.

is there a way to test the output of the pins? ill look into that, thanks layne

r u still running the 911 turbo fuel pump? would the stock fuel pump work?

yes i am, as far as i understand, the stock pump should work fine, but when you start needing high volumes of fuel, the stock pump wont give it to ya

[jrcook320]

yes i am, as far as i understand, the stock pump should work fine, but when you start needing high volumes of fuel, the stock pump wont give it to ya

JDB is fueling 240 hp on the stock pump running k-jet. I don't know what his system pressure is set to, but with fuel pumps, flow rate goes up as pressure decreases. That means when you set it to 40-45 psi it will be able to flow higher volumes and support more HP than it would on a higher pressure k-jet system.

I'm running the 911 pump because my system pressure is set at 90 psi. At that pressure the stock pump's flow rate is too low to fuel that kind of power.

[oldstylebimmer]

Dj what's the status of your car, you get it tuned?

[BoomerDJ]

im still tuning, i recently blew the head gasket, the cause was that i installed the toothed trigger wheel to the Dynamic timing mark on the flywheel not that TDC mark wich added 25 degrees advance to whatever the computer was doing. so under 10-12psi, full throttle in 4th gear about about 4k rpm, i was advance nearly 50 degrees, can anyone say problems? i got that fixed and OMG it idles better then it has ever idle since i have owned the car. i will keep more updates as i get them.

[pommeree]

How much boost are you making out of curiosity?
Did you have to do anything to secure the injectors to keep them from popping out under boost?

[BoomerDJ]

How much boost are you making out of curiosity?
Did you have to do anything to secure the injectors to keep them from popping out under boost?

between 10 and 12 psi. and the injector rail bolts to the manifold, they are not going anywhere

[oldstylebimmer]

sounds good, im glad its working out! keep those updates coming

[BoomerDJ]

ok so i got alot done today. i grabbed a stock throttle cable and wow the throttle is buttery smooth now, huge difference over that cheap spectra cable that was there. also fixed some exhaust leaks and bought some 1awg welding cable to replace the peice of poo wannabe 4awg wire that was there. now the car starts perfectly. i also bought a mangaflow muffler and im going to order the cat on monday, hopefully have those on end of next week.

ive been doing some tuning and so far everything is going well, but id like to put out a request. does anyone have an ignition map for a boosted m10, id like to compare what im using to some other people. when i am happy with my maps ill post up my msq and maps

pics will be coming soon

[FranzE21]

Very impressive, nice to see that thing go hard, post up some drifting videos, or a launch (slip the clutch to preload so you can spinem hard from the line). This is all on a 1.8L motor right? did you rebuild this thing? I always thought my 1.8L was a little rough when compared to a 2.0L

[superj]

find goodntight from e30tech. i think he is on bimmerforums also. he megasquirted his m10 and turboed upto 400hp, if i remember right

[n8orange51]

Hey u wanna do this to my car I have a 83 320i m10 I would like to chat with u about your kit

I wanna do this to my car