As requested, the dyno chart I mentioned previously is posted in my album (yso191's)

Steve

 

Sandpa

I have yet to see hear even a remotely plausible explanation as to why an air filter change can have a effect on over-run mixtures. Now almost any change on the exhaust side of the motor can have huge effects. EFI tuning all about predicting air flow and resonant frequencies. As the AC is on the open air side of the throttle body that is closed at this point, it is hard to by either of these things are coming onto play here assuming the AC is plenty large enough to work at WOT.

Now a slight shift in the AFVs that have now pushed something over a magic limit may be believable.

Remember that popping out the exhaust requires three things to happen. Raw fuel in the exhaust, oxygen in the exhaust and a source of flame.

Bring this up in the EFI 101 thread and we can toss it around.

 

yso191, if I'm reading it correctly, it looks like the ied actually made the afr leaner.

 

aal,

It does appear that way. I just chocked it up to my lack of understanding or some reversal. I can't imagine: an increase in torque & HP by leaning the AF ratio, nor the factory setting being 13.8:1 (which is what the XiED is supposed to produce). If on the AF ratio graph you reverse the colors it reads as predictions say it should. Is there another explanation I am missing?

Steve

 

yso191, you're right; it seems like the colors got reversed. Hopefully someone with a knowledge about these things could comment.

 

The IED voltage divider causes an indication of being leaner than it actually is. The ECU sees this voltage as a lean condition and adds more fuel to return it to the original target.

 

No CR I'm not saying that the stock A/C is necessarily too rich. In theory, the K&N filter allows freer flowing air. This little difference may have been all that was needed to eliminate the decelleration popping above; it would not be uncomnmon. Most riders can tell when they are operating with a dirty filter = less gas mileage amongst other things.

Back to the Honda example above, the VTX has a valve in the exhaust port in the heads that will add air to ignite the unburnt fuel in the exhaust during decelleration. This causes the exhaust ignition to occurs in the exhaust port & in the exhaust pipe before the mufflers. The stock mufflers make the popping undetechable. When aftermarket pipes are added (that are freer flowing), the problems surface and are detectable with decelleration popping. A lot of Honda owners with aftermarket pipes remove this air induction system & MOST of the decelleration popping stops.

 

gs34doc, as far as the dyno goes, any explination of how / why the colors on the dyno chart could have gotten reversed? I assume the dyno afr is off of a probe inserted into the exhaust pipe, to show actual afr, not the afr assumed by the ecu.

 

That quote was in reference to my referral to post 2905 in this thread. In that referred-to post, I included a link to a graphic image I'd developed. The image shows, essentially, the fueling characteristics of two different types of exhaust plumbing. One is the touring model hybrid 2-into-1 / dual exhaust and the other is plain old dual exhausts. I'd originally developed the graphic for a thread in the touring forum where folks were talking about using a conversion kit to replace the wye pipe and make the system a "true dual" setup, with no need to re-map the EFI. As you can see, even if you don't understand what you're looking at, the "landscape" is quite different between the two types of systems. There's no way an engine mapped for one will run "fine" after changing system types and not re-mapping. It might run close to okay, but most of the EFI's adaptive features will be operating far from the center of their ranges.

If you already had a dual exhaust system and put a different one on, the changes would not be so dramatic. There would definitely be changes if one had an interconnect of some type and the other didn't, but those changes would not be as pronounced as the comparison in my image. Nonetheless, there is no denying that a re-mapping to match any breathing or operational changes is going to be the best possible route to take. Always and for every reason.

As to why folks are reporting what they're reporting, I usually conclude their level of understanding (thus ability to accurately assess the situation) is not good enough when they report things I know cannot be true in the strictest sense.

If someone came on and said something like then I would have not much different to say than I've been saying, which is Either it's merely informative as to why what happened happened, or it's informative as to why it might not be a good idea, decide for yourself, now, if you still want to do that.

Now in reference to the specific points you make in the opening quote, you make no mention of what type of exhaust system you switched from, and that is a major factor. You mention an alternate air cleaner assembly, and that, in and of itself, really necessitates a re-mapping, even if it's the only thing done.

Once you open the can of worms known as "needing to re-map the EFI" by altering the breathing in a fundamental way (different type of exhaust plumbing and/or different air cleaner assembly), as opposed to, say, (reasonable) slip-on mufflers and/or something like a K&N air filter element for the stock airbox, then these *IEDs become irrelevant. If you need to re-map these devices will not help you for two reasons. First, because they are not capable of re-mapping in any way except to raise the level of the entire fuel map the same amount. Second, because if you do re-map appropriately, you will no longer have a need for IEDs, period.

 

Hate yoursrelf how?

I'm in "quote" mode, so have lost all post-number designations. I'll assume post 2922 refers to my post about the differing Volumetric Efficiency values (common factor in fuel calculations) between two different types of exhaust systems.

My first clue towards "how do I know?" is that it's a 2004 model you're talking about. It did, and likely does not have closed-loop operation, so any discussion of any IEDs, pertaining to it, is totally irrelevant.

What else have you got?