|
Title: Tune fuel cut at low rpm Post by: wayne on December 14, 2016, 05:00:09 PM Hey everyone,
I tuned my A3 1.8t (AUM 032FC) for running on e85. Fuelwise, it has a 4bar fpr and scaled krkte and full load target lambda to match with e85. The fueling is perfect everywhere except for one thing that bother me on daily driving and fuel economy... The fuel cut only appear when above 2.2k rpm and most of the time when it's downhill. (lambda stays at 1) Ideally I'd like to cut the injection as soon as I lift the throttle and as long as I'm above for example 1400rpm. I think it would decrease my fuel consumption a lot doing that and get a better driveability since I have no engine brake below 2k rpm except in very low gears... Any ideas on where to start ? If you have any idea on how to tune for economy with e85 on partial throttle low loads, I'm interested for my daily driving and long trips. Not because e85 consumes more etc but to get the most out of it in every situations. Where I live it's more than half the price of gas and for the performance I get out of it there's no point running on crappy 95. Title: Re: Tune fuel cut at low rpm Post by: vwmaniac on December 14, 2016, 09:44:17 PM Believe it or not this thread has the answers your looking for http://nefariousmotorsports.com/forum/index.php?topic=7174.0title= you just need to set these items opposite of what everybody in there is doing
Title: Re: Tune fuel cut at low rpm Post by: wayne on December 15, 2016, 04:31:21 AM Thanks Good idea !
I did'nt see it that way... I have some questions about KFNWEGM (see linked photo of my current map) What are the value on the Y axis (0 1 2 3 4 5 6 7) related to ? my fuel cut seems higher than the rpm mentionned in the map even if I lift off the throttle for a long period... Should I decrease these values ? They seem already low... Title: Re: Tune fuel cut at low rpm Post by: spacey3 on December 15, 2016, 04:55:52 AM The values on the Y axis are gear numbers. As you say, they're low enough already... Have you checked out the fuel cut delay time?
Title: Re: Tune fuel cut at low rpm Post by: wayne on December 15, 2016, 04:59:10 AM If it's KFTVSA, it's all set to 0.5
If not I have no idea what map it is... Title: Re: Tune fuel cut at low rpm Post by: spacey3 on December 15, 2016, 05:18:24 AM That's it yea.
Do you have any logs of it happening? Title: Re: Tune fuel cut at low rpm Post by: wayne on December 15, 2016, 05:34:32 AM NO,
I just monitor the lambda staying at 1 when I'm below 2200. However, I forgot to tell that when I'm decelerating from for exemple 2500rpm the lambda goes to full lean until the engine reach to 1300 to 1500rpm. But not when I decelerate from 2000rpm Title: Re: Tune fuel cut at low rpm Post by: spacey3 on December 15, 2016, 06:21:13 AM I had a look at my definition file and KFNWEGM the rpm to reinstate fuel after fuel cut only.
There must be some other variable/table (that I do not know of myself) to state the minimum rpm before initiating fuel cut. I've had a look around but can't see/find anything obvious. Title: Re: Tune fuel cut at low rpm Post by: wayne on December 15, 2016, 06:33:22 AM That is making more sense and seems to follow what I'm seeing as for when the lambda get back to 1...
Anyone ? |