Please elaborate. That does not seem to jibe with what I have pieced together.

That sounds somewhat engineerish. I will assume you meant ... average pressures... at the times... the valve[s ] are open, otherwise I have to think you refer to the minute amount of time both valves are off their seats at or around TDC between the exhaust and intake strokes (wherever the median of the lobe centers is and depending on total durations). Aside from the appearance that you have factored out the piston displacement from the equation you leave me puzzled by that snippet. Please elaborate further. If you have attempted to simplify the statement for my sake, I would take it as a personal favor if you would not hold back, I am fairly confident I can fully grasp anything you want to throw at me and this all could ultimately take fewer words.

Pardon me for finding humor in that sentence. I always consider air to be the gaseous envelope we live in which is comprised chiefly of ~80% N and ~20% O, and which I have found in personal practice to be entirely unburnable

But I know what you are saying, though not necessarily how it correlates with what you had said just previously (maybe it will fall into place when you flesh that out for me).

Again, more flesh please. My sources of information and experience would lead me to believe that intake absolute pressure is factored in (the somewhat simplistic, tight-lipped, and perhaps even misleading language in the SERT manual from last year could even cause one to believe they are somehow getting values from both sides of the butterfly [which maybe only happens initially regarding ambient pressure at engine startup, maybe also somehow considered during WOT?]).

I agree that TPS is a poor singular quantifier, but do not understand or believe it to be used that way currently. Please enlighten me further! Rest assured I want to be right about this, but not at the expense of anyone else. I want us all to be right. Lets get to the very bottom of it.

 

Rider, I answered your most recent PM just before I started on that previous reply above.

I do not want to derail the discussion onto this topic only, but does anyone with access to a Digital Technician setup know what the AFV does for a cylinder immediately after throwing a lean/rich code? Does it stay at its limit and work its way back down or does it immediately revert to a previous, or maybe a preset value, like maybe 100% or something? Please try to catch one live by disconnecting a sensor or maybe increasing or decreasing fuel pressure and let me know, okay?

Thanks.

 

Speed Density by definition&nbsp\\;uses the absolute air&nbsp\\;pressure in the intake times a VE value (correction)&nbsp\\;that is RPM and MAP&nbsp\\;based table.&nbsp\\; The primary component of this VE is a correction to account for the gasses that were left behind by the previous combustion and exhaust event.&nbsp\\; At low RPM this unburnable&nbsp\\;gas (as the o2 has been used up) is fairly significant.&nbsp\\; So at low RPM the VEs are in the 40% range in most true Speed density systems.&nbsp\\; As you get close to the torque peak a motor tends to get real close to 100% VE.&nbsp\\; At high RPM the pumping losses in the intake and exhaust tend to roll this VE back off to about 90% VE&nbsp\\;right before the rev limiter normally sets in.&nbsp\\; Harley for some reason elected to use a RPM and Throttle position VE map.&nbsp\\; The MAP pressure either comes from the MAP sensor or from one of the hidden tables known as the Map_Default_Table.&nbsp\\; The reported MAP value on some of my data loges exceeds the ambient air pressure and unless this is from ram effect of the intake it appears the bike may even be using some sort of synthetic MAP value based on a MAP lookup.&nbsp\\; Who knows?
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The air flow into and out of the cylinder is indeed a wild calulation based on pressure differential accross the open valves.&nbsp\\; Not just the valve overlap.&nbsp\\; Most EFI systems have a correction table for backpressure in the exhaust that is aggrivated by ambient air pressure.&nbsp\\; I am working on a system now that goes way past these basic assumptions.&nbsp\\; It all has to do with "engine modeling".
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I would love to&nbsp\\;see&nbsp\\;a new thread started to allow us to take this up a few orders of magnitude.
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AW
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So if i'm not getting codes, my Xied's are not working?&nbsp\\; I have seen no codes, but i'm getting some popping on decel only.&nbsp\\; I'm running stock a/c and rush 2.0's on my FXDF.&nbsp\\; I have 1600 miles and put syn3 in for my 1000 mile service.&nbsp\\; Runs much better, but that popping has been bothering me.&nbsp\\; I ordered the PCIII and a big sucker A/C.&nbsp\\; Can i run the PCIII and Xied's together?
Thanks.

 

Okay, I am following you so far. Looking forward to some face time.

Several orders of clean magnitude!

About the wild calculation, all my handheld calculators use either RPN or RPL. Bring it on! I will save a bunch of keystrokes over an algebraic-entry-laden device...

 

You can, but if you are properly using (making the best use of) the PC-III they will not be hooked up to the ECU.

In one sense this site is really, really, unreal. Sorry, MNrider, nothing personal. There are relatively few fundamental things to learn about this engine management stuff and there is no way in hell I would personally even try much of what I see being talked about here without first learning the fundamentals. To me, $20,000 for a motorcycle precludes wild speculation concerning its well-being.

 

MNrider,
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Just because your not getting codes does not mean your XIEDs are not working.&nbsp\\; You should be able to tell the difference in ridability when they are on.&nbsp\\; If you do suspect they are not working see nightriders website.&nbsp\\; He explains a test to do to check them.&nbsp\\;
As far as the PCIII goes, it may be possible, but the way the PCIII is designed to work is by eliiminating the 02 sensors alltogether, with the use of supplied 02 eliminators.&nbsp\\; Since the XIEDs go inline with the 02 sensors, you would be negating the whole design of the PCIII.&nbsp\\; Unless your a whiz at mapping and have your own dynometer it probably is not recommended.

 

JLB0038
I see that you have done AC, mufflers and XIED's, no SERT or fuel management system? I am contemplating just doing that. Does it work OK? You drive a lot out of closed loop?

 

I have a Digital Tech here in the lab.&nbsp\\;A 131 or 151 code does no correction the the AFV. Disconnecting a sensor does. Sensors that have been disconnected will correct the AFV to 90% value and a CKE light. These sensors are the IAT, MAP, CHT and either or both O2 sensors.

 

The AFV goes to 90% Does that mean the the entire map is leaned out by X times .9 or you end up leaner with any one of those inputs disconnected?
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That matches what I got when I disconnected my o2s and data logged the results.&nbsp\\;The&nbsp\\;PW did get leaner by about 90% of the original PW. I wonder why they do that?
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&nbsp\\;
AW
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