My tune is MAP and it starts at 15. It increase in increments of 5 until it gets up to 75. Then it increase at 10 to 100 %.


Looking at my log file I see where the kpa sank as low as 13.6. So say I had a decel pop at 2800 rpm. Then I would go to 2875 rpm and 15 MAP and increase that number on the VE tables for both cylinders? How much would you start with, 5%, 10%? First going richer and if that didn't get go leaner than original settings by that much?

 

The second one he show's is DE, the description clearly says that "DE causes transient fuel to be removed for a short period of time. This effects 'popping' and backfire when backing off the throttle".

Key words - short period of time and transient fuel.

Short period = momentary. So if you decide to coast from 4500 RPM down to an idle DE is totally taken out of play. So if you have bad decel popping at 1750 RPM and let off at 4000 RPMs you'll still get the decel pop at 1750.

Transient fuel = During positive throttle (MAP) additional fuel must be injected than to account for the fact that not all the fuel injected will make it into the cylinder. If additional fuel were not injected a lean condition would result as more fuel is puddling on the valve and port walls rather than entering the cylinder.

Conversely, during negative throttle (MAP) transients, less fuel needs to be injected than commanded to account for remaining fuel that is still boiling off the walls. If less fuel was not injected a rich condition would result.

So basically DE shuts off the additional fuel for a millisecond when you let off the throttle to stop the additional un-burnt fuel from igniting in the exhaust.

Like I said earlier, right or wrong this is what I have learned over many years of doing this, I can't speak for Lonewolf but it appears he is under the same thought process I am. I don't get where you thing adding fuel to the decel part of the VE tables is a lengthy process though, you grap a bunch of cells and raise or lower the value globaly, takes seconds at most. Seams like adjusting the DE, then riding it and maybe adjusting it again would take a lot more.

I hope you don't take this personally, I respect you knowledge and what you contribute here, i'm not saying my way is right or wrong, i'm just saying that my way has served me well for a decade now, I don't have a clue how many bikes i've tuned in that time, but I do know last year when I was at Roeders it was 264 full tunes in 8 months. Your way works for you , my way works for me, in the end all that, matters is that the people's bikes we work on are satified.

 

Mac, I tried using the decel enrichment table on my old 08 and it helped it for shifts and very low rpm, but didn't stop it. I ended up raising the afr to 13.5 at 20 tp to stop it in the lower rpm range. I just got the small pop pop at 2800 rpm and never really tried to fix that.

 

Sorry I missed this earlier. I'd take your 15 and 20 columns in your VE tables from 1500 and up and raise them by 10. Remeber, in those two columns anything above 1100 RPM's is only reached on decel. Just don't go into any of the columns to the right of that. After you make changes I always suggest you "save as" and name it something else, go in sequential order if you want, that way if you get worse results you can always go back to a previous MAP

 

I see now. Looking at my log files I see my bike at idle is in the 30 kpa range. So to stop a decel pop I would richen the 15 to 20 kpa columns in the range where the decel pop occurred. That is sort of what I did in the AFR table to stop the pop on shifts originally. I am not having any decel popping on my 2015, but I have not really started tuning it as of yet and I just wanted to understand what everyone was saying here on this subject.


Thanks everyone, you are never too old to learn. You may forget it.......

 

I haven't said anything about short period or momentary or Transient fuel. The jpg I posted and got my information from is from the TTS manual. I attached it again. It says "temporarily removes fuel when the throttle is closed" and not what the throttle position or map Kpa is. Temporarily is not a measurement of time. To me it means until something is done to change the temporary position. It also says this table effects exhaust popping when backing off the throttle. It also says it stops decel enleanment when the throttle is advanced above 3% again. Incidentally TTS built the tuners for Harley until early 07.
I too have already said if it works for you keep on doing it. This way works for me and I have done it on over 100 bikes and never had an issue. If the VE in the first column is excessively lean I change it to a more realistic number before I put the map on. I have seen VE's in the 50's on some maps and no amount of DE adjustment will fix that.
I may be mistaken but I thought the intake runners were dry on the Harley fuel injection system as the injectors spray directly at the intake valve, and the valve is slightly tulip shaped to prevent the puddling and cause a smoother transition for the incoming fuel and air mixture. I guess you could get some reversion and get fuel droplets on the walls at low speed, but don't think that would happen above 2000. On Carburated and wet throttle bodies then this is an issue. Port injection not so much. That is why when you port the heads and match intake or enlarge the runners you don't polish them on carb or wet throttle body systems. If polished they attract fuel droplets. If left slightly scratched it will create slight turbulence and break up the fuel droplets and keep them from sticking.
"Quote from Watchfuliz
Mac, I tried using the decel enrichment table on my old 08 and it helped it for shifts and very low rpm, but didn't stop it."
I suspect that would be the VE tables weren't set right to start with. I looked at a ve table from a stock 08 touring and it was in the low 70's and high 60's in the decel area. I would change that to atleast high 70 and low 80's and if you got a pop then the decel table could fix it or you could adjust the VE table. We are all saying the same thing, just hung up on the momentary or short time. AE is definitely momentary.

 

Guys... you are scaring the sheep.

I'm not the Master Sensei of anything here but seems to me that you guys are talking about the same thing but working both ends to the middle on an Octopus. It's not that complicated, use paragraphs wisely and remember that each of us has our own way of doing things, yes?

 

You are right I have been beating a dead horse. I had to look up what a Master Sensei was. Now I understand, it is one of those Wax on Wax off teachers. We don't have any sheep where I live so that one went over my head.
Mac

 

I have an Aussie (heard dog as per my avatar) They run around in circles herding sheep. "Spooking" to keep them in order.

 

I'm looking for some help with my tune. I have been getting popping between shifts so I made the changes on page one. I didn't get as many pops but still get some mainly between 2nd and 3rd. Also my Mpgs have been around 35 and at best 37. I would like to be getting at least 40 mpg.

Any help would be appreciated.