Standalone ECU from Scratch

[Andrew7dg]

So I have been working on this for a while now and it has been enjoyable. I thought I should share this info and later I will make something like a how to for this system because there isn't very many for the MSII system.

After lot of people telling me I should go with DSMlink with going standalone, I kind of took a side step and went with a less traveled route. I took the plunge and bought a MegaSquirt system. DSMlink sounded tempting because of the ease of just putting the system in and go however I checked my ECU and I have a non Eprom and not only would I have to find an ecu with an eprom I would have to go and get the DSMlink upgrade. Megasquirt so far hasn't come close to the cost of a DSMlink. However the Megasquirt need a lot of time to put together. I am going to see if I can break even by selling the MAF-T and the ECU.

For those people who don't know what a MegaSquirt is, it is a standalone ECU that you can buy as complete or as a kit to solder together.
More info:
http://www.megasquirt.info/

The kit that I bought was the new Megasquirt 2 processor which has a lot more features then the original processor. The board version that I have is V3.0 There is only a handful of dsms that are running the MSII processor but the ones that have been running it have had great success and I have heard very little complaints about the system. I bought parts from DIYautotune.com. Very good people to work with.

Assembly of V3.0:
http://www.megamanual.com/ms2/V3assemble.htm

So far in the assembly, I am almost completed with the kit and just have to do the modifications to get it to work for a 4-2 CAS (miatas almost have the same cas or code). I will post pictures of what it looks like later. All the test along the way have been proving successful and megatune (software for tuning the megasquirt) is fairly user friendly.

Main reason I went with this system is the idea of building the ECU from scratch sounded fun to me. Most of the parts I have on my car have been from scratch. Also building the system would give me something to do over the winter.

[User Name]

Dude, you should be going to M.I.T. or something.

Good luck though, sounds fun! I've seen a few people running this MS on Toonerz now.

[crazy_skier]

are you planning on having a shop tune it or doing it yourself? My buddy wired his turbo 420a up with this and has it running decent, but wont spend the money for an hour of dyno tuning and you can definatly tell. other than that I think its cool, plus you can ditch alot of the wiring and clean up under the hood a TON!!!

[mdost03]

Turbo 420a's have been using MSnS for years, seems to be the most cost-effective and most indepth standalone on the market for the money.

[Jungy]

ryan i dont ever member you riding in my car since i went MS? ohh well i"m still just as fast as your old car when chris got it back from LSE wit the gt3076r. Are you gunna get a dsm again or what?

[Jungy]

I'd love to go msII, when I built mine the neon/420a code didn't work wit msII. Are you planning on just tapping into the factory harness for all you sensor signals?

[Andrew7dg]

Originally Posted by crazy_skier

are you planning on having a shop tune it or doing it yourself? My buddy wired his turbo 420a up with this and has it running decent, but wont spend the money for an hour of dyno tuning and you can definatly tell. other than that I think its cool, plus you can ditch alot of the wiring and clean up under the hood a TON!!!

Well most of the wiring underneath my hood is cleaned up already. My battery is relocated in the back and that gave me much more room. What is nice (depending who you talk to about MAP vs MAS) is that I don't have to mess with a MAS sensor. I have the MAF-T sensor but that is coming out and I am just putting in a section to replace that. In the replacement section is where I am placing the GM IAT sensor. Should be close enough to the intake to get a fairly good reading.

I am going to try to get a good tune on it first by the instructions. Someone on the msextra is going to give me a starter MSQ file that should be simmilar to what I will be running but there is always differences between engine and it would have to be finer tuned. There is a software program that will look at the data on a given run and suggest changes that can be made to the tune. I am more interested in tuning it my self but if it gets too overwelming I will probably take it to a tuner. However all the instructions are very well laid out to tune it. It really shouldn't be that big of a problem.

Originally Posted by Jungy

I'd love to go msII, when I built mine the neon/420a code didn't work wit msII. Are you planning on just tapping into the factory harness for all you sensor signals?

I don't know when you bought yours but I think it can support it now. I think it is in testing yet but here is how to take over ignition

http://www.msextra.com/ms2extra/MS2-Extra_Neon.htm

It wasn't long ago that MSII could be run on dsm and it still in testing.

To my surprise is that the modifications to the MS board is very different from MSI to MSII for the DSM. So if you think about just changing the chips, it will probably cause problems. The instructions are fresh for the DSM 4g63 but later I want to post a how to that will simplify the instructions.

For the harness what I am going to try to do is find a bad ECU and take the clips off of it to plug into the stock harness. From there just match wires from ECU to sensors. I figure if I didn't like the system or if I have a problem, I can always switch back.

Something kind of sexy about this system is the flex fuel sensor option

http://www.megasquirt.info/flexfuel.htm

To sum it up short, a flex fuel sensor can be used to determine the ratio of ethanol to gas and compensations can be made. Think about that, have the option of putting E-85 one day and Regular unleaded fuel the next day

[Jungy]

Yeah msII works with the neon/420a code now there are guys on 2gnt.com that have been runing it for a little while now. Msextra.com is very useful there are alot of experienced ms tuners on there, there really wasnt anyone that had run e85 on the 420a when i started tuning and I got alot of help to start me off from the guys at diyautotune over on msextra.com. With mounting your ms in an old ecu case make sure there is no way the ms can make a ground loop, you arent even supposed to mount the ms case to metal. Sounds like a tough project with connecting the ms to the factory ecu plug but i know the ford, bmw, and miata guys have done it!

[Pushit2.0]

What is the rest of your setup? Maft and an AFC can go a long way if setup right.

~John

[Andrew7dg]

Originally Posted by Jungy

Yeah msII works with the neon/420a code now there are guys on 2gnt.com that have been runing it for a little while now. Msextra.com is very useful there are alot of experienced ms tuners on there, there really wasnt anyone that had run e85 on the 420a when i started tuning and I got alot of help to start me off from the guys at diyautotune over on msextra.com. With mounting your ms in an old ecu case make sure there is no way the ms can make a ground loop, you arent even supposed to mount the ms case to metal. Sounds like a tough project with connecting the ms to the factory ecu plug but i know the ford, bmw, and miata guys have done it!

Just to clarify I am not going to use the old ECU case, I am just using the connectors to plug into the harness. I will solder wire from the old connectors to what the MegaSquirt plugs into. It should work out pretty well. I haven't figured out where to mount the ECU though... I need a place that I can hook up a serial connector.

Originally Posted by Pushit2.0

What is the rest of your setup? Maft and an AFC can go a long way if setup right.

~John

Well I know they can but I kind of wanted to go standalone instead of piggy back. I kind of wanted to get into real tuning with the ECU and make the most of my modifications. Plus I wanted to run the bigger injectors for maybe E-85 and take control of the timing. As you know piggy back systems don't have that possibility.

So it was between DSMlink, AEM, and Megasquirt. I am not saying that DSMlink and AEM aren't bad systems. It just seemed like Megasquirt seemed to be the ECU for me because you can build it from scratch and I love building thing from scratch. Plus the MSII system and processor has huge possibilities. Plus I can't beat the price so far...

I am really not that happy with the MAF-T. I think the old MAS did a better job of reading air. Especially in this cold weather I am finding out. I was going to switch to a 2g MAS and AFC but realized my goals are too large for that combo.

Modifications are pretty light right now

Before I did real big modifications to the car, I wanted to make sure this system will work with the car that I have. Kind of establish a base tune and then tune every modification from there.

The modifications are going to get big...
Remember a couple post ago
I found a 4g64 in an expo not that long ago.

[Pushit2.0]

Going big? I doubt that. 2.4s are good for street cars and breaking drivetrain. If you want to go fast 2.0 is where its at. Last I checked Shep or Brent do not have a 2.4. Yes the MS2 is a standalone but the resolutions and tuning ability on startup/idle/cold start/warm start suck vs the AEM or Link. I hate Mafts with a passion but they can work for making power if setup right. And you can vent your BOV just like in F&F. The only down side to staying 2g mas is the restriction befor the turbo.

~John

[JET]

Originally Posted by Pushit2.0

If you want to go fast 2.0 is where its at. Last I checked Shep or Brent do not have a 2.4.

~John

Those 2 guys don't have a 2.4, so that means you can't make them fast. I don't think he meant going 8's when he was talking big. There are plenty of fast 2.4's out there.

[Pushit2.0]

I am sorry that my idea of going big is not at the newb level anymore.

~John

[Andrew7dg]

Originally Posted by Pushit2.0

Going big? I doubt that. 2.4s are good for street cars and breaking drivetrain. If you want to go fast 2.0 is where its at. Last I checked Shep or Brent do not have a 2.4. Y I hate Mafts with a passion but they can work for making power if setup right. And you can vent your BOV just like in F&F. The only down side to staying 2g mas is the restriction befor the turbo.

~John

wow... where did this come from... I got a quote from F&F and blow off sound
But since you work for LSE how many DSMs have you tuned with not a MSI but with a MSII? I am just curious on how they liked them? This doesn't count the 420a running them. So far everyone on msextra have loved their system and wouldn't use anything else, even DSMlink. Am I in the wrong direction? Computer to computer the resolutions of MSII are faster then the stock ECU. This is why it is able to run bigger injectors. Still the injector size that I want to run is way too big for just a simple AFC. By using a AFC and a huge injector, it throws the whole timing off. Best to go to something a little more standalone.

The Cold, Idle and warm up "suck" because it is only till recently that someone was able to make the stock IAC work with MSII. MSI couldn't do that. Even then people can adapt another IAC from another car to work with it. No one has taken the effort to do that and just let it run cold. This is probably what you seen.

it was said that going big, I meant 2.4L level not HP...well that will come with it...


Please explain more if you are going to say
"MS2 is a standalone but the resolutions and tuning ability on startup/idle/cold start/warm start suck"
and 2.0L is where it is at because of Shep and Brent...
and please don't use POWER as a term. I HATE that term because different people have different perceptions of POWER. For example 300hp seems low to me and 600hp seems high but someone else might find that 300hp is REAL POWER.

I am looking for technical feed back.

[Shane@DBPerformance]

A lot of people don't like the Megasquirt software. But it's isn't as bad as it could be. Most MS users are going to rave about it, since they probably haven't dealt with many other real standalone systems. A lot of shops won't deal with installing and setting up a MS system because they end up spending much more time/money on the install and setup than if they just went with a tried and true solution. That might not be a problem for a guy doing it all himself who can a lot of his free time installing, researching, etc.

The speed of the MS has nothing to do with being able to run bigger injectors. The stock DSM ECU can handle big injectors without problems and can handle huge injectors like 1600s better than a lot of standalone because of it's good injector drivers. Engines run at an extremely slow speed compared to computers, it doesn't take much processing power to run an engine. Most of the time an ECU is just sitting around waiting for the motor. Big injectors are very slow to open, that is their main problem. You can make them work better by using a real peak & hold injector driver, which gives a big initial voltage spike to pull the heavier/big injector open quicker and then uses a smaller voltage to hold it open.

The MS is a good option for you though. People like DSMLink because of it's ease of tuning and the DSM factory knock system is just about the best out there.

[iceminion]

Ok, I need to sit down with you and pick your brains, I am the "project manager" of a DSM with a 2.4/gt35R, the works....

We ran out of money for an AEM, so we went megasquirt (MSII v3)

Its not over my head, but I just want to make sure I am doing everything right.

As for the ECU placement, its going in one of two places.

Center console or under the stereo.

with all the wires from the stock harness gone, bolting it directly to the bottom of the stereo unit will probably be the best option, giving access to the data port for easy tuning.

I also want your base maps.

I will buy you beer if you want, to let me tag along for the wiring, if you need a heated garage/well lit to install it, i have one.

[Pushit2.0]

I was saying an up side to the Maft was the BOV venting, not directed to you. I will not lay out the whole reason behind what I said, what would I gain, nothing. It will work and if you want to spend the time on your car with it, good luck it should be a fun project. I have not delt with a MSx in a DSM I have delt with it in a turbo ford probe.

~John

[Swifty1638]

that turboed ford probe is also...uh..yea. Not anyone's favorite vehicle in that shop to work on that I remember! lol

-A. Swift

[niterydr]

Yeah once all the miss-install was figured out, life was good...

Good luck the the Megasquirt. They are alot cheaper (to the tune of around $1200 pending sensors/used vs. new, etc) and if your labor/time is free, then it is a likely good investment. Be VERY careful assembling the board as they are really prone to bad grounds/bad connections, and mis-guidance by "experts".

I personally think the resolution is very poor, especially considered to other standalone ecu's, but for the poor-mans ecu upgrade, it is a good option.

It is personally my last choice solution for a DSM, but everyone one is different.

[Andrew7dg]

Well I I finaly have it finished and I bench tested it to make sure it is in working condition. It is running fine! I even hooked up a spare 4-2 CAS on a drill to make sure that everything was working OK.

The box is the ECU itself

The circuit board is the tester that I can control simulations like RPM, Coolent temp, TPS, O2, MAT






When the weather warms up a bit, it will be installed into the car.

I am still thinking of how I want to install it however.

There are two ways,

I can use this as a fuel controler, or I can use this for both fuel and spark.

If I hook it up just using fuel I would have to splice into the harness for all the signals. I would however have the ability to just run fuel and not have to worry about tuning the spark for right now.

The other route is just take control of fuel and spark. That way all I would have to do is remove the stock ECU and just hook up to the existing harness. No splicing. This also means that I won't have to deal with a MAS or what I am running right now a MAFT


Here it is in action:
http://s217.photobucket.com/albums/c...t=DSCN1830.flv
The lights are alternating with the flashing in real life. I think the cameras resolution didn't quite capture it well enough. On the board the lights on top are the injector banks firing and on the front cover and on the other lights on the test board are the spark outputs

This is sweet as hell. All it started out was with little resistors, diodes, chips and other stuff. All soldered together and it is alive! Kind of like rebuilding your first engine, you never would think that it would run and suprised when it does...