Nightrider O2 IED's - Field Test
#2942
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.
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.
#2944
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
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
#2947
@realbob. Do you mean that you think the stock version is too rich? That is new in this thread! On the decel-popping. I think you have to define what this is. Are you cruising at f.e. 80 miles per hour close the throttle or accelerating at WOT and abruptly closing the throttle immediately afterwards. Decel popping must mean that there is an unburned fuel mixture in the exhaust is it not. if you are cruising along and close the throttle there is very little change of being an unburned mixture in the exhaust, especially since the ECM will likely cut off the fuel until 1200-1500 rpms (same as with modern cars?) When increasing rpms at WOT and suddenly closing the throttle I can imagine that some of the very rich mixture can get into the exhaust pipe unburned and explode there because of a better AFR. Again how you define decel popping also determines whether one should look at it as a problem in my opinion. Suggestions any-one?
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.
Last edited by REALBOB; 08-28-2008 at 05:06 PM.
#2948
#2949
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
You know, I don't understand how this engine management stuff works, but I had a couple of specific problems, or at least operational characteristics that I didn't like, and by doing [fill in the blank] they are no longer present, near as I can tell. Maybe I've introduced other "problems" but so far they have not presented themselves to me at my level of understanding and/or knowing what to even look for. All I can say is that if you have the same "problems" I originally had, at least doing what I did may help you with yours, too.
Here's how our system works and what doing what you did with it will bring about as a result.
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.
Last edited by glens; 08-28-2008 at 04:24 PM.
#2950
glens I'm going to hate myself 4 this. post 2922 how do u know? my son has a softtail standard 2004 air cleaner kit and vance & hines long shots we took it to a dyno they ran it! conclued it would not bennefit from any fuel management device PERIOD they said that the bike could not be dailed in any BETTER. my point well guess it just doesn't matter does it
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?