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]

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.

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]

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

~John

[Andrew7dg]

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.

:pc:
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. :sasmokin: