Reducing Decel Popping?

[barbagris]

Won't hurt to lower temp a couple degrees , my fan cuts in at 98 . Also have the rev limiter upped whilst they are in there !

I dropped my fan to 95.

 

[kaivalagi]

Yep, doing some more reading and digging based on my decel issues between about 1400 to 4400 rpm, I can see looking at the default 20776 map that the F-L Switch is telling my bike to use the L tables for all the troublesome areas I've had...that is correct right? Even with O2 turned off L tables matter as the manifold pressure is also used right?

Using the graphic view for F L switch makes things a little clearer I think, anything below the line is L map based, above the line is F map based from what I understand now right?

So assuming I have got this right....this view of the default 20776 F L switch tells me that the L tables will be the issue for me where TPS is less than 20% and revs are below around 4500 (issues where TPS is up to 30% for upper revs too, but this is less noticeable cause the bike is f'ing loud!):

But looking at the same for Hans0 maps as he's zero'ed off the high rpms the L tables are less important in the higher rev range, and for anything under the line in the lower revs the L table will be used (below 2K rpm no throttle is the concern with L only):

The most important bit I think
To cope with the L table still kicking in Hans0 has positive fueling for zero pressure for all rpms which I suspect helps stop decel popping immensely...as I suspect with no restrictive can or cross over pipe I have pretty much nothing there top stop major pressure loss at the manifold when laying off the throttle...

Looking further into Claviger's maps he's zero all the F-L switch values so the L tables are effectively not used I am assuming...this would also address my issues I suspect...

Now, assuming I have that right, I hope that a de-enriched Hans0 map (as per my screenshots), to allow for standard air filter and headers, will be more appropriate for my bike....

Again, any comments/thoughts are most welcome...I'm still trying to get my head around it all Just hope I've got it right and not horribly wrong lol

 

[barbagris]

Using the graphic view for F L switch makes things a little clearer I think, anything below the line is L map based, above the line is F map based from what I understand now right?

That does make it easier - Now realise what it is telling you. At 3500 rpms in top you are doing ??? mph?

L is Manifold Absolute Pressure controlled.
F is Throttle Position controlled.

It has been a while since I bothered with the Narrow Band O2 - Either with a plug or adaptive disabled (o2 box unchecked) - But iirc even when the Lambda is tricked to being always 1 with a plug - the ECU will log 0.95 and 1.05 lambda. I never really resolved this but was leaning towards it being associated with L or F too.

 

[kaivalagi]

That does make it easier - Now realise what it is telling you. At 3500 rpms in top you are doing ??? mph?

L is Manifold Absolute Pressure controlled.
F is Throttle Position controlled.

Stay within the law and it's all L map and economical

 

[barbagris]

Stay within the law and it's all L map and economical

Even well outside it's often L. And NOT necessarily economical. I am currently deliberately running on L all I can - 35.31mpg (imperial) But smooth. And (shock horror ) - yes some popping.

 

[kaivalagi]

But do you think having zero fuelling for zero pressure in L would go some way to explain it running very lean and decel popping as a result?

I don't think I'll ever eliminate it with such an exhaust but it needs reducing, no one would put up with this much, no way!

Have I made some sense with all this?

 

[barbagris]

But do you think having zero fuelling for zero pressure in L would go some way to explain it running very lean and decel popping as a result? Have I made any sense?

Here's the thing - if there really is ZERO ABSOLUTE pressure - Then the manifold is at ABSOLUTE VACUUM - So no air is getting pulled in either.

 

[kaivalagi]

Here's the thing - if there really is ZERO ABSOLUTE pressure - Then the manifold is at ABSOLUTE VACUUM - So no air is getting pulled in either.

When I say zero I mean the zero column in the L table i.e. up to 220 hpa

If the throttle is zero'ed and the engine has nothing to do on an overrun other than engine brake couldn't the pressure drop to below 220 hpa / 20% atmosphere making the fueling zero for a very short length of time?

I am assuming Hans0 put some figures in there for a reason to add fuelling within these pressures? Why would he have done that?

edit: Here's the change in L table zero (0-220) pressure values to use +ve fuelling:

Maybe I am clutching at straws here but if nothing else there are major differences in the maps and it could be worth a shot using a Hans0 map, with reduced F table fuellings to align back to the TORS map, to see what happens right? I've compared 3 hans0 maps so far and all use the exact same L table values and almost identical F L switches.

 

[Nat67]

Stay within the law and it's all L map and economical

How do you do that ?

 

[kaivalagi]

How do you do that ?

I have no bloody idea...all I know is these tyres aren't cheap!