Anyone have aftermarket ECU tuning experience?

[exdeath]

Looking for programming/tunning guides/tutorials/examples, etc.

Basically if I wanted to do a brand new standalone ECU out of the box on the 'start it up and drive it to a dyno' default tune on a new engine build and then do all the tunning myself, what would be involved?

I'm sure its more than just fuel and ignition maps. What else is involved, and can you actually write microcontroller program code, triggers, etc.

This would be for a 3S-GTE, but anything in general would be cool

Thanks

 

[natto fire]

Hi,

I did the same thing on my friend's '92 Integra. We started out using a Hondata system, because it was easy to tune. Then AEM came out with the autotune feature, and we have been using that ever since.

The most important thing, if you are planning on tuning on-the-fly, then you will need a wideband O2 sensor. We were using a NGK sensor, with an FJO controller. This is not important which brand you use, (essentially, only NGK and Bosch make wideband O2 sensors, and each have their advantages/disadvantages, which I could go into further detail.)

You could just go to a tuning shop and rely on their O2 sensor, but street tuning is so much more accurate as far as final result.

The spark table is really easy to set up, but the fuel, not so much. To do real tuning, you will need a wideband O2 sensor to monitor your AF:R. From there it is fairly simple, try to keep full-throttle in the 10-12 AFR range, and partial throttle in the 12-14 range.

Also, as a warning, some states are really gung-ho about their emissions laws. Keep in mind that most stand-alone ECU (like the AEM EMS system) are labeled for "off-road" use only, and are essentially illegal in panty-waist states. (California and others with stricter emissions laws)

The options with the AEM system are so numerous it might make your head spin. There is the "launch control", "traction control", and various other options that can be triggered from the various sensors...

 

[exdeath]

Thanks for the info. Yeah, wideband goes without saying.

But the fuel table itself really is the focus of the tuning after everything else is set up once on the initial config?

Could you describe what the tables are like? I'm guessing its typically 32x32 with RPM vs. load (via MAP or MAF signal), etc, but I know there are also secondary tables and offsets for special conditions like WOT vs. cruise, knock detection, coolant temp, etc, I've just never actually watched what goes into a tuning session at the computer itself. And what do the values represent when you see the table on the screen, raw injector pulse widths? I can see how that would be trial and error trying to relate something as arbitrary as 'pulse width' to a real number like AFR.

I'm thinking it goes something like drive with a WOT pull in a 1:1 or near 1:1 gear from as low as possible to red line with a AFR datalog (and a real time gauge so you can back out if need be) and then go in at each RPM and +1 here, -.75 there, etc.

The table is the final actual injector pulse width right? ie: it's never adjusted on the fly, but rather the index into your table is what is modified according to external parameters (temp, TPS, etc) ?

I'd really like to get into that aspect of it myself being that:

a) there aren't any performance tuning dyno places here in Tucson, I think there is one but they specialize in Subaru's or something, and
b) being a programmer and computer person I should be doing it myself anyway. Kinda embarrassing that me, who codes in assembly blindfolded, has to seek out experienced tuners to work on the computer in a car...

I'm looking at putting a 3SGTE and E153 in my Camry in the future and figure it would be a great opportunity to get some complete electrical and tuning experience under my belt. I'm thinking AEM or Motec M4 at the moment, but the Motec is probably overkill for my performance goals (400 WHP on pump gas with 2.2L stroker and most likely a TD06 or GTxxR turbo) and a waste of money.

 

[iamwiz82]

I have a Greddy ECU and it does fuel based on default plus a percentage. I can program it from of of 5 or 6 different sensors. I use a pressure sensor. I then made runs and watched the datalog of the AFR. Since i have a modified stock ECU also, it tries to keep AFR at 14.7:1 until I hit boost, when I then adjusted it to keep around 12.5:1.

As Captain HOwdy said, the number of parameters are crazy.

 

[steveox]

I'm in the same boat as I'll soon be working on tuning my G-Reddy E-Manage for my Turbo Matrix project... that install should begin in a week or so... I have a tuner to do it for me but I would really like to learn how to make some changes myself if the time ever came around...

 

[exdeath]

I think the best thing for me would be to just plug it all in with a relatively stock engine where nothing can really get hurt, and just play with stuff until I get the hang of it. I'd be first putting in a stock 3SGTE with 200-255HP just to get it to fitted, mounted, wired, and driving and get the hard part out of the way. Once the mounts and harness are good, then the engine comes back out and gets built and upgraded, etc. I could use this opportunity to swap a plug and play AEM on the factory harness and learn the complete process on a safe and conservative power level and get experience tuning the stock setup for maximum power within safety constraints (detonation, etc).

Basically just change a value and see what it does and then try to correlate what it means It would be a project car so I'm not worried about down time or messing things up in the name of learning.

I just hope it comes with a comprehensive programming manual or data sheet that describes how everything is computed under all conditions and what each table is for, etc.

 

[Toastedlightly]

Well, I am currently trying to help tune my brother's SRT4. We have an AFC NEO (I think that is who makes it.. same people who make the safcII). It is difficult, even with a wideband O2 sensor, to get the mixture right. Then again, we are running 750cc injectors (and on the Neons, you can only take fuel away, not add it). Overall, get a wideband O2 sensor and have someone to watch it as you pull in 3rd gear (w/ a manual), and make slight adjustments from there. See if someone also has similar equipment to you, and tune from a little bit richer than their settings.

 

[exdeath]

"can only take fuel away"

That sounds more like a piggy back fuel computer that just plays tricks with the stock ECU to adjust the fuel trim. The point of a complete stand alone after market EFI computer is that you can control absolutely everything by replacing the factory ECU completely. But then you are starting from scratch with absolutely nothing save for an "initial start" tune or a self learning "just to get it up and running and drive it around in the yard" tune.

Some systems even come with a blank harness with like 10 feet of cut end terminated wire that you have to wire yourself completely from scratch. Gives even more flexibility of adding your own sensors, actuators, etc, and being able to program a number of aux inputs and outputs to do whatever you want. Like turn on water injection or intercooler sprayer automatically at a certain boost, temp, or rpm, then retard boost and timing if the level indicator in the meth bottle is low, etc. Very powerful and flexible stuff, but takes more skill to work with. Basically, heres some injectors, a MAP or MAF sensor, an ignition controller, and some wire and a blank box to program yourself to control them, what do you want to do?

 

[natto fire]

Yeah, tuning a piggyback system is nothing compared to a standalone solution.

Sorry for the late response, but to answer your questions, yeah the number you see is raw data, but you can do percentage bumps for each cell in the table, which helps out a lot. Also, when I quit tuning, AEM had just released an auto-tune feature, which would adjust fuel tables according to your target AFR for that RPM/load range. The initial problem was that any other data was extrapolated on any spot you did not hit on the auto tune. Also, the AEM comes with pinouts for various other functions (like boost control, and launch control), so it is very handy especially for boosted FWD vehicles. (3S-GTE )

There are tons of base maps, especially for popular engines, that allow for different injectors, etc.

As you noted, the stand alones provide so much more functionality that they are a must for even the lowest of super street tunes. If you are planning on upping the boost or changing to a bigger turbo, and want more than 275+ WHP, a standalone is the way to go.

 

[imported_Truenofan]

got a question in the same direction as his, which one of these would suite my purposes best, im trying to make a 300whp fc3s with a reubilt motor.
this one
http://www.rx7store.net/product_p/aemems.htm
or this one
http://www.rx7store.net/product_p/interceptor%20x.htm

i plan on running this car on pump gas(which is more than easily done, even up to 420hp). im just not sure which one would suite it better.

 

[Toastedlightly]

Originally posted by: exdeath
"can only take fuel away"

That sounds more like a piggy back fuel computer that just plays tricks with the stock ECU to adjust the fuel trim. The point of a complete stand alone after market EFI computer is that you can control absolutely everything by replacing the factory ECU completely. But then you are starting from scratch with absolutely nothing save for an "initial start" tune or a self learning "just to get it up and running and drive it around in the yard" tune.

Some systems even come with a blank harness with like 10 feet of cut end terminated wire that you have to wire yourself completely from scratch. Gives even more flexibility of adding your own sensors, actuators, etc, and being able to program a number of aux inputs and outputs to do whatever you want. Like turn on water injection or intercooler sprayer automatically at a certain boost, temp, or rpm, then retard boost and timing if the level indicator in the meth bottle is low, etc. Very powerful and flexible stuff, but takes more skill to work with. Basically, heres some injectors, a MAP or MAF sensor, an ignition controller, and some wire and a blank box to program yourself to control them, what do you want to do?

That actually sounds easier than the piggyback system I am trying to deal w/. Also about 1000-1500 more (for this car anyway) than the standalone

 

[exdeath]

Originally posted by: Toastedlightly

That actually sounds easier than the piggyback system I am trying to deal w/. Also about 1000-1500 more (for this car anyway) than the standalone

Yeah thats the idea. It quickly becomes impossible to do much when you have 15 piggyback modules spliced into the stock harness all fighting over control of the stock ECU functions, etc.

Better to just replace the ECU and harness and do it from scratch from one box like its supposed to in the first place. The most expensive one I know if is the Motec M4 Pro and thats like $2,500+ but thats like top of the line. I haven't looked at them in a while but I think they even come with a built in wideband O2 and onboard datalogging, etc.

If you know what you are doing (and I've never worked with a ECU like that before), it is much easier, but there are probably many trivial things that the stock ECU takes care of that you take for granted until you go to a standalone and have to program it from scratch and half the accessories on your car don't work anymore