Because the oxygenated fuels will require a few percent more fuel to reestablish the correct AFR. This same percentage more fuel will be required the same everywhere. This is a linear change.

When you alter the exhaust, you change the breathing differently in different areas of operation. This is non-linear. When you alter the intake, you change the breathing differently in different areas of operation. This is non-linear. When you combine the non-linear changes, you have a more complex non-linear change from stock. The computer still thinks it is stock and will try to provide the linear changes necessary for the stock equipment it still thinks it is using. Therefore, your modifications will result in a non-linear operation as compared to stock. This non-stock-breathing situation requires specific non-linear correction to reestablish the equivalent of the linear stock condition. The engine management system makes linear corrective measures. At least more linear than would be required of your changes. Thus there will be areas of operation which will be incorrect.

To further complicate things, the linear changes provided by the computer will be based on non-linear input instead of something linear like oxygenate fuel, so the non-linear results can and will produce even wilder swings from what you really want or need.

On a stock engine package, the *IEDs produce non-linear results because they are linear when non-linear was required. Saying it from the other direction, you wanted non-linear results but linear ones were provided. You wanted more fuel in some places but not all of them. You are getting more fuel in all of them. This is non-linear net effect, even though the fueling changes were linear. But they should not have been to be correct.

When you put *IEDs on a totally stock engine package, you are rolling the dice. When you put different breathing parts on without appropriately correcting the fueling somehow, you are rolling the dice harder. When you combine that situation with *IEDs, you are rolling the dice even harder yet.

 

and

and

That one an entire response, evidently, to a question of where the *IEDs function, or maybe where the Adaptive Fueling functions, it is a little unclear.

Rider, you seem to be offering conflicting information. Between the first two quotes, which are all given in the order the posts were made, in the first you say the EMS will learn new breathing parts. In the other two posts you say the adaptive functions do not impact open-loop operation. If that were true, how could you say the EMS will learn the new parts? Most certainly there will be fueling changes required for open-loop operation with those parts. Would not you agree that the bulk of the fueling changes required with those freer-breathing parts would actually be in the open-loop areas?

True indeed. Especially when concerning the claims of the IEDs having limited effect or that the XIEDs allow the O2 sensors to function properly, much less ideally.

 

Disbelieve me if you wish. But do yourself a favor and have a look at the thread in this very forum, Advantages/Disadvantages with Closed loop ECM.

Doc 1 is certainly one of our forum members most knowledgeable with our current EMS. He works/tunes with them daily and travels to train other techs how to tune them. He rarely offers verbose input and seems to pretty much always stay out of stuff like this thread. Read the thread and what he says in it in response to the questions, okay? Consider carefully the questions and the answers. They have a direct relationship to what I have been trying to get you all to understand.

 

It was a reply and there in no conflicting statement except what you are reading into it.And the AI article was and is correct.If you truely knew the present ecu system you waould not be making the statements you make time and again.The AFV tables ARE NOT used in openloop.Openloop operation are&nbsp\\;SET VALUES..It WILL NOT CHANGE.The AFV tables change BUT ARE NOT USED IN OPENLOOP.

 

&nbsp\\;Glens, I finally think I get it re: oxygenated fuels and add on accessories.&nbsp\\;Thank you. Bottom line thou, do the XIED's or IED's cause any REAL harm other than some uneven fuel delivery thru-out the entire throttle span 0-100% using slip-ons and a/c. I wish I grew up 30 years later so I would understand computers&nbsp\\;(ecm) better, but than I would not be retired.

 

Someone in the know told me this re: XIED'S.
The open loop fuel map AFR's above 4k and 50% throttle start at 13.8:1 and
go to 12.5:1 depending upon RPM and engine load. A change in exhaust/ac
would only change these AFRs about .2-.3. So even at heavy/full throttle,
the OEM ECM is more than rich enough to handle the upgrades.

 

Glens is now stuck defending a idea that has no merrit.
And I still stand by my statement that he wont help anyone out in other threads asking for help on SERT questions.
But he will come on here boo-hooing a good product.

 

&nbsp\\;
So, my question still remains....
&nbsp\\;
&nbsp\\;

 

ViEDs is the best choice. Spend the extra $30 or so, and have whatever you need.

 

Rider57,&nbsp\\;How would someone accurately adjust VIED's (also ft. to back cyl)&nbsp\\; E mail/PM ??