socketed ECU, stock ECU, whats exactly the difference?

[DustinsDuster]

so Colton offered to sell me a socketed ECU with spare chips.

what im really not too clear on is what the difference between a stock ECU and one that has been socketed. im assuming that a socketed ECU can take different chips to change the tune? are there any other options as far as what you can do to an ECU to be able to change the tune of the car? whats "better" to have so to speak?

[krustindumm]

The tune is stored on an EPROM chip, that's what the socket is for. So there really is no other way to change what is stored without changing the chip. There are emulators that can replace the chip, and devices which modify input or output signals, but the only way to really change the tune, is to socket the ECM.

[DustinsDuster]

So say i was to have Trevor or someone else tune the motor when its in the truck- how exactly is this done? Where does the laptop hook up to? Would the changes made to the tune be saved to the chip or what? Please excuse the "noobish-ness" of the questions, ive just never dealt with tuning\modding computer-controlled cars.

[Drifte]

if you wanted to say go from 50cc injectors to 550, then use maybe a gm maf instead of the stock maf or the 2g maf. you can buy the chips pre tuned, and have a lot less work on your hands.

theirs more to it, i'll have to find you some links maybe.

[logans dad]

basically what the chip does is give you a way to get home if you loose battery connection. It has to match your injectors.

Trent unhooked my battery and lost the tune so it went to default chip tune and runs but not well runs rich.
I don't know what truck brand your putting this motor in but with my car it has a connection from the factory for the Mitsubishi shops to hook up their electronic stuff. I think its kind of a universal thing between cars. I might be wrong.

[krustindumm]

The *plug in* is called a DLC (data link connector) or OBD port. OBD-II is standardized (96+ only), OBD-I (92-95) and pre-OBD are not. I started typing out OBD-II standards, but this http://en.wikipedia.org/wiki/OBD-II_PIDs will be easier. You can see that you can not tune most car's through the DLC, and the few that can generally require the manufacturer's equipment.

In most cases you do not hook a computer to a stock ECM to tune. You have another device (such as a wideband controller) which will log the A:F values while your driving, you then make corrections to your program, and burn that to another chip with a EPROM burner, then swap the chips out. Some chips are erasable, some are not. Since the ECM is socketed, you can plug in an emulator, the emulator is a device that allows you to make real time changes to the programming because it is connected to the computer. Once you have everything correct, you would burn the program to a chip, and remove the emulator.

There is usually a set of base instructions stored on the ECM somewhere, so incase you install a bad chip (or no chip at all) the car will run, but not well. The fuel maps you program on the chip do not have to be perfect, because the ECM still has the corrective ability that it had with the stock chip. When you disconnect the battery you loose these corrections, but not the maps themselves. IMO you should be able to get the maps close enough that you can't really tell when the ECM has been reset.

If you want to play with a program, download one of the many GM or Honda tunning programs available for free. They are very easy to use, and some of them do offer built in datalogging.

[DustinsDuster]

so is a "DSM Link", and the other devices like that i hear people talk about, an emulator like Krustin is talking about? if not, what are those used for?

[logans dad]

if worse comes to worse you could use mine to tune it until you get something. Once its tuned it will stay unless you loose juice to battery or unhook it.

[krustindumm]

I have tuned with DSMlink, but I've never looked into how it worked until now. I just flipped through the site and it looks like they replace the eprom with one that permits tuning through the DLC.

The idea is great, but from my experience with it, I would not recomend it. It worked very well, no crashes, instant adjustments, but it is only 2 dimensional. I was using it with a MAF-T, which may not have been setup correctly, and was suprised by how limited the tuning range was.

[TbTalon94]

Alright Dustin here is a little view in the DSM tuning world. Since your basically going to have a DSM in a truck this is your options and tuning availabilities.

One thing you can get no matter what you do is a Pocket logger. This is just a program and a chord that you install on a Palm of some sort, and you can log any data comming through the DLC like krustin said. This can be very usefull if you are tuning with an AFC, gm maf-t, chips, etc. This can view timing, knock, airflow, rpms, tps, etc. etc.

Permitting you have a eprom/socketed ecu:

1. get a chip from keydriver.com that includes a very decent tune, 2-step, injector correction, idle correction, rev-limit set, etc. These chips do wonders and really make the car run good. They go for around 125 new. You can also ad an AFC to this combo to add some adjustability to the tune. The only thing you can adjust on the chip is 2-step limit and i think rev-limit. I have a keydriver stage3 chip in my Talon right now along with an AFC.

2. get DSMlink. This lets you adjust anything you need to an extent. Fuel, Timing, Airflow, Injector sizing, rev-limit, 2-step, anti-lag, idle control, etc. etc. This is one of if not the best tuning option in the $500-0 range. With DSMlink you can do anything you need and it's fairly easy to tune. I can tune it for you and walk you through it to teach you how to make adjustments when needed.

Permitting you have a non-eprom ecu:

1. Get an eprom ecu and revert back up to options for eprom ecu :)

2. Get an AFC. This will let you adjust fuel via airflow. You can control 550's and 650's with a good tuner (i'm capable) but the downside is your messing with airflow so it will also change your timing. Less airflow = less fuel but also means more timing. More airflow = more fuel but also less timing. It can get kind of tricky. Not that hard to use and great for just fine adjustments that you need.

3. Get a GM MAF-T. This is a little control box that translates the signal from a 3" or 3.5" GM maf to the signal of your stock maf. This reduces A LOT of restriction and you can also vent your blow off valve without negative effects. This is if you have it in the "blow-thru" configuration. The MAF-T is just like the AFC though, except it has no screen. Just knobs. It does have a little higher range of adjustability, meaning the afc can go -/+ 50% depending on what afc you get, and the maf-t can go to -/+ 60%. Those may not be exact but you get the idea. You can also add an AFC to this combo and get even a finer tune. But with the price of both you could just get DSMlink and not have to worry about timing issues.

4. Get a "stand-alone management system" such as Megasquirt, AEM EMS, Haltech, etc. All of these are usually really expensive, very difficult to use for a beginner, and usually not so user friendly. They do have a GREAT range of tuning and can do anything you want, but again aren't for the beginning tuner and require a good deal of time to get a tune right.



There are a few other options, but those are the basic principles. If ya got any more questions ask away.

-Trevor

[DustinsDuster]

Thanks Trevor, ive kinda been hoping youd pop up in here with a big list like that.

how hard/expensive is it to convert a stock ECU to eprom?

[TbTalon94]

eh you can't really convert a non-eprom into an eprom. Some 1g's came with them and most all 95 DSMs came with them.

You can find eprom ecu's all over the place. Some are cheaper then others, but they usually go for 150-250 range. Depending on the condition of them, capacitors replaced, sockets, etc. etc.