GM Stand Alone ECM Swap

[Edub1]

I'm really getting tired with the pathetic state of ECCS tuning and I'm starting to consider this swap that a local GM specialist turned me on to.

The swap uses a GM ECM that I believe is a speed density type. The thing is, this can be sourced from a junkyard and all the ECM's functions are well known. Plus, it is designed for turbo apps up to 3 bar (MAP). And it supposedly will work on any car.

Check it out.

http://www.diy-efi.org/gmecm/ecm_info/1227749/

Here is one guy using one in a supercharged 928http://p-928.home.comcast.net/749.html
Modified by Edub1 at 6:51 PM 3/27/2007

[KATwo40]

THANK YOU EDUB! This is the exact same emotion I have toward ECCS. Anyone who DOES know about the ECCS is super cryptic about it. And the real kicker is, it's not like people WANT to stay with the ECCS because of it's amazing capacity to run the engine better than anything else out there.

Sheesh.

I'm gonna look into this Edub. Thx for the link.

[Chezedik]

So the advantage is that all functions are known, how hard is wiring everything up? I would guess it is all about using GM sensors too. How hard is this hardware to get? What kind of cost?

[Edub1]

I think most of it is just a matter of matching appropriate pinouts. It uses a MAP sensor. The ECM is fairly universal GM, used on the turbo Sunbird and the Cyclone trucks as well as a number of other cars. Also, this is a hugely popular swap because it adapts to any motor and yes, the full function and code are known. Rumor has it an engineer at GM absconded with the source code. There is a guy on Ebay with 49 of the ECMs for sale cheap. The rest could be sourced from any junkyard I am sure.

If we got a handfull of people together, I would be willing to do mine (with supervision) and then provide a base tune for 460cc injectors. My guy has done many of these swaps but he doesn't work cheap ~ $1,000 for a dyno tune. So, I'd need about 10 people or so to help keep the cost down. Once we have the base tune 90% of the leg work is done - I will buy a camera, do an all inclusive write up and we can all go from there.

[WDRacing]

There was a guy in here a long time ago that swapped in a DSM ecu, sensors and injectors. Worked great and ran 12's IIRC.

Swapping a new ECU is fairly staright forward if you have the wiring diagrams. Swapping the sensors is as easy as aquiring them. Any ecu thats been used and tuned alot will be a good choice.

Good Thread

WD

[Chezedik]

Edub, why can't we take the known existing timing maps and fuel maps and install a tune. Does it use a direct number for PW? Can't we just use TunerPro and use the addresses for the ECU we get the ECU from, then wire it up to ours?

Or is there something else I am missing.

BTW, shoot me a link on that ECU guy, maybe I will pick one up if it is as cheap as you say. Afterall, I am about to have a spare harness, and I still have my Burn1.

[Edub1]

Edub, why can't we take the known existing timing maps and fuel maps and install a tune. Does it use a direct number for PW? Can't we just use TunerPro and use the addresses for the ECU we get the ECU from, then wire it up to ours?

Or is there something else I am missing.

BTW, shoot me a link on that ECU guy, maybe I will pick one up if it is as cheap as you say. Afterall, I am about to have a spare harness, and I still have my Burn1.

Cheze, check out some of the links I've provided. I don't know jack about tuning this system. Timing probably could be copied to a degree but nobody knows what the values in our fuel map represent. There is a lot to learn. This is why I'm suggesting pooling resources and paying an expert to get the ball rolling.

Here is the last email I got from the Ebay guy. I don't want to bug him too much though.

If you check out http://www.thirdgen.org technical articles you will find a article on repinning the harness from a 1227730 TPI car to run the 1227749 computer system. Then find a 4.3L turbo memcal, I have 2 but I am not ready to part with them yet as they were next to impossible to find. AYBN 16164174 or BBZB 16181579 would be the 2 latest releases for the prom codes and part numbers so you can check with http://www.gmpartsdirect.com and see if you can still buy one of these new. You will need to check with http://www.diy-efi.org on modifying the programming for a 3 bar map as I have only used them with the stock 2 bar map but I know some of the SYTY guys run more than 15psi boost but I don't know what they do to the programming to run the 3 bar map.

[Chezedik]

I am thinking about this. I know that no one knows what the stock #'s mean, but we can do the very same thing the tuner will do for fuel. Set the #'s across the board and add/pull fuel accordingly. The real nice thing about the GM setup is that it will only require one emulator.

Why can't any ECU work, why does it have to be a turbo GM? Wiring the harness won't be that tough, and chips are cheap. The only problem I can see with using the non-turbo computers is that the Memcal will be for non-turbo. But at this point it will run like a dog turd anyway (Memcal is like the backup ROM provided on ECCS, it is good for limp home function in the event of a computer failure).

The GM ECU is actually really easy to understand, and I like the idea of this simply because the adaptive strategy is much more advanced than this crap we have on ECCS. You can change injectors without changing tunes (within reason), and it can figure it out.

I may go to the boneyard and see if I can get an ECU and harness clip. Does the turbo ECU offer wastegate control, or is there some other reason we need it over a non-turbo. In fact, now that I think about it, in their golden years, GM only had about 6 ECUs to control all of their models. That's why they created the PROM system, rather than this crap we use, and that Ford and Chrysler (worst engine management ever!) were using at the time. I may start collecting sensors now.

I am on board with this.

[Chezedik]

Check Mark Manur's Tuner Pro. You can set # of cyls and all sorts of other tune information. This means that we would be able to set the engine up for DIS also. VATS can be disabled, and I think you can even wire certain dash lights to operate as shift lights.

The functions of the GM ECU seem already much better than those of the ECCS. This might work well.

So much to learn...

[180sx]

ISN'T CYCLONE A V8? how are you going to disable the other 4 cylinders. But 1000$ is steep, rather get motec, haltech or sds , even megasquirt.You can run any motor of any ecu pretty much. I myself would steer away from gm and if you want quick easy Map-based tuning get honda p28 ecu with hondata or dsm ecu and chrome and a harness plug. Than just match pinout wire to wire.Plug and play.Eccs is fairly basic , people make it more complicated than it acctually is.. But yah it lacks functions and for rookiees Map is easier to understand than MAF.

[Chezedik]

Motech and Haltec ARE GM ECU's. Just different packaging. All of the sensors and programming are GM. Also, you don't disable 4 cyls. The ECU has a cyl # setting. So you tell the ECU that it is 4 cyl, and it is. You have the wrong mindset about the GM ECU, it isn't like ours where you have 1 ECU for 1 motor with 1 trans option in 1 year. They used 4-6 ECUs during the late 80's and early 90's. So they had to incorporate a ton of options into 1 ECU.

I also disagree about MAP being easier than MAF. MAF is way easier to use, but MAP is a little easier in boost. I don't think it would be any easier or more benefitial to get the Honda or Mitsu ECU. In fact, I think this would be cheaper and more functional.

You don't have to do it if you don't want to, but I think I will.

[TheOne]

the cyclone was a V6 with a turbo & AWD truck(pickup).(also typhoon)

thats a nice option, does this also include the ls1(ls1edit) ecm's?.

[Chezedik]

I just thought of something, what do we do for IAC? Do you expect that the Bosch unit on the mani now is a stepper? I thought I remember it being duty cycle modulated.

The GM uses a stepper motor.

[Edub1]

I think the IAC operates independant of the ECU. You guys really should have a look at some of those links, there is a lot of info there. This ECU is fully cracked, it can run 4,6 or 8 cylinder motors and is a speed density MAP system. I guess we will have to find the turbo module or buy new ones. As for the price, the guy is talking putting the car on his dyno and doing a full tune. Maybe it can be done for less, maybee we can figure something out. I don't have all the answers but this guy tells me this is the way to go and that no other system is as well deciphered. Do some Googling and see what you can find.

See this link under schematics service infohttp://www.diy-efi.org/gmecm/ecm_info/1227749/
Modified by Edub1 at 6:56 PM 3/28/2007

[Chezedik]

Nope, the IAC is fed voltage and is called a stepper motor because given a certain number of "steps" it is turned in by the computer is how much it controls the idle given certain inputs such as the PSP switch, A/C Control switch, and the Alt Load switch.

Each step is 31 degrees of outward rotation towards it's seat. It is fully seated at 255 steps (FF hex) and is open anywhere from 40-100 steps during normal operation.

It is a computer controlled system, and this will have to be addressed since, given what experience I had with consult, the stock unit is duty cycle. This means probably using a GM TB, which will require machining a special adaptor or making an all new manifold.

EDIT: Here is a link to Tuner Pro, play with that and see if you still think we would have to pay a tuner:

http://tunerpro.markmansur.com/downloadApp.htm

[Edub1]

I have Tuner Pro and I've seen a bin for these ECUs. There is a list of like 100 things that can be adjusted.

Check out this link under schematics & service documents.

http://www.diy-efi.org/gmecm/ecm_info/1227749/

Guys are putting this swap into everything with wheels.

[Florida240sx]

Just send your ECU to scott at enthalpy $500 your good to go. need a retune 150... how much are goign to spend just in sensors??

[Chezedik]

I think this is about a little more than this.

[Edub1]

Here is an xdf file for tuner pro.

syclone58_2_3bar.xdf - 0.31MB

[Florida240sx]

Looking at as: hey universal device for any project.... just need sensors... Depends on how much sensors will be... wait what would be needed?? just tps and mafs and spark.... and emissions crap for you tree huggers j/k

[Chezedik]

Dude, it's a GM! Crank sensor - 18buxIAC - 30buxTPS - 23buxMAP - 20-100bux (depending on 2 or 3 bar choice)Cam Sensor - 20 buxKnock Sensor - 40 bux

Maybe my prices are a little off, but point is that GM sensors are cheap. Again, what do you think you use if you get Haltech, Motec, Megasquirt, and many others? GM engine management.

[Edub1]

Enthalpy only tunes DE motors. But even so, download the xdf file and view it with Tuner Pro. I don't think anybody has that much control over any Nissan ECU.

Regardless, please don't disrupt this thread - I'd like to keep this going in a positive direction for those of us that want to explore this option.

[Poor_S13_Driver]

By your last post EDub1 sounds the SOHC can be run off this? Me likey If i read right any car could be run using this systems. (So essentially I answered my own question) Im watching this thread like a hawk. A lot of spoils are going to be avaliable for the taking

[Florida240sx]

Scott can do different ones. But has lots of experience with ka's and sr's

[Chezedik]

Any car can be run off of any system if you are willing to put in the time, and you can see benefit enough to do it. Remember an engine is just a chunk of metal that needs 3 things correctly timed to run.

Any engine management system is capable of doing that (if it is standalone), the GM is just the most cracked, with a lot of features.

The Delco EMS was years ahead of the jap systems. It is just typical ricer mentality that keeps us using ECCS (or maybe lack of understanding/funds).

[Edub1]

The GM unit is made to adapt to 3, 4, 6 and 8 cylinder motors both N/A and turbo.

I would suggest that we make this a goup effort and that everybody interested start doing some research and posting your findings. There is tons of info on the net about this swap. See the one about the supercharged 928 - awsome. Anyway, instead of wasting time speculating, let's all start Googling. BTW, check out that XDF file - holy shiite!

[Chezedik]

Right, my other concern besides the IAC setup, which I think could be resolved by use of an adaptor on the IACV line on the Nissan mani, would be the '800' line.

The 800 line is the multiplex line used in GM cars and trucks that allows the ECM to share data with the BCM, PCM, and ABS modules. My concern is can this be turned off in TunerPro or will it even throw a check engine light at all?

As far as having to use the 1227749 ECM, because of it's capability to use the 3 bar MAP, why not just use the 3 bar map on another ECM, by changing it's lookup tables? Afterall the principle difference between the 2 and 3 bar maps are that the 5v signal occurs at 14.5psi and 29psi respectively. If you adjust the lookup to indicate that 5v represents 300kpa, then you are golden. The downside to doing this is the loss of resolution. But if you intend to run more than 15psi, it may be worth it to you.

Also, a Holy Shiite is just a righteous muslim.

[Edub1]

Cheze, did you open the XDF? It sounds like you know quite a bit about these systems, how about researching your questions and letting us know as I don't think anybody here has an answer for you. All I know is that my understanding is that it's supposed to be a breeze to adapt this to any motor. My local guy said guys were running it on turbo 5.0 Mustangs and blowing people away untill word got out.

My neighbor is a CAD guy and said he can make a short CNC run if we need an adapter bracket, so that's covered.

[Chezedik]

The machining is the hard part, I will look to see if 800 can be eliminated, but I doubt it would.

I will look and let you know what I come up with.

[Edub1]

Another Good link with schematics and other tech info.

http://www.cruzers.com/~ludis/p4xref.html#1227749

Also, I think Moates.net sells a memcal adapter so we can use a standard EPROM chip.