How lean is TOO lean in the AFR Maps ?

  • Ken in Cairns
    Ken in Cairns
    6 years ago

    Have been looking into this whole EFI fuel mapping thing, I used to tune carbies years ago, but work on big diesels now, and while I understand the principles of it all, I haven't come across an actual example of what a "Good" fuel map and AFR table for a 103 actually looks like.

    I understand that every engine is an individual and has one fine band of tune that makes it really sing, but they also all fall into a range were the will be fairly happy, if not perfect, and this is the ball park numbers I'm after.

    I also understand that these engines run on the hot side, especially with the stock tune, so had fuel table ARF's set so the cruise was 14.3, but I was told by to run it at 13.2 and 13.8 in the cruise part, this just sound to be very rich especially as I know what my pipe and plugs looked like with a tune not as rich as he said to run.

    So I am asking the question of you guys that have a lot more knowledge about these engines than I do, what is the safest or recommended lean mixture I can run in the cruise part of the AFR table, the 1800 to 2500 RPM band and the first four or 5 columns in the MAP pressures ? Sorry I can't open up the race tuner software at the moment to give you the exact numbers, I'll edit this post when I get onto my computer later.

    As some of you guys know I have a big trip planned in about 5 weeks, Cairns to Moruya NSW and back, via the Western route going South, Injune, Roma, down to Parks, and via Bathurst, Goondiwindi etc on the way North, a bit over 5000 KM round trip.

    So I want to maximise the fuel economy while retaining the reliability and available power, but not run it so lean to the point were I cook the donk, or have other issues.

    I have just tried a new map from what I had, slightly leaner in the cruise part of the AFR from what I had been using as the discs on the exhaust were covered in black carbon fluff ( so it looked like it was a little rich, the plugs were on the rich side too, not grey or tan, more a very dark brown/black), I also advanced the timing in the Cruise part by 2 degrees (no spark retard events recorded in the runs either) , and the engine seems to like it, plenty of power, max cylinder temp recorded during my tuning runs after 20 minutes of running out to the highway and then several mid throttle and several full throttle and high speed runs was 205 as recorded by the Screaming Eagle Race Tuner.

    Engine is pretty stock, just the big sucker air filter and a Supertrapp 2 into 1 exhaust.

    She is not as sprightly off the line as she could be I guess, but she pulls very well from about 2400 all the way to redline, hardly any decal popping like I had with the old pipes and tune, but there was little bit (a couple of small pops) when I ride her hard, but I have also increased the decal en-leanment a bit on this new map and is sound pretty good to me now.

    The biggest problem for me is I don't have a lot of "Harley" experience, and don't know what these engines feel like in different tune states, I am learning, but it's not like I have a pool of bikes I can compare.

    So any help you guys with the tuning experience can give me would be greatly appreciated.

    Cheers

    Ken




  • steelo
    steelo
    6 years ago
    I hope you get an answer Ken. And if you do, one that won't cause your engine to break down. After all, this information is usually tightly held by blokes who made a big investment and make a living dynoing and tuning engines. As you said, each engine is different so what may be optimal in one motor may be too lean in another. Good luck though.
  • fatbat
    fatbat
    6 years ago
    Get onto the TTS mastertune website and download the TTS manual. Then read it over and over. It tunes the same tables as the Se tuner but has a much better manual explaining things. 
    I tuned this way two bikes ago but it takes a lot of time, patience, trial and error and reviewing lots of data. When I started screwing around with ignition timing I started worrying at which time I decided it was pretty sensible to pay $600 and get a professional dyno tune from somebody that does it all the time and can monitor data in real time. Especially ahead of a big ride. 

    Good luck with it. 
  • robots
    robots
    6 years ago

    Go and up your VE tables 10-15 pts globally go for ride and inspect plugs


    plugs are one of the best indicators for how any petrol engine is running,


    run bike at 14.60 all day long, will not blow up, there preachers running all around US on tourers with just slip ons

  • Ken in Cairns
    Ken in Cairns
    6 years ago

    Thanks for the replies guys, first off I agree with what you are saying Steelo, which is why I was only asking for a ball park range to begin my fine tuning.

    Thanks for the advice Paulybronco, I didn't release that about ULP, I only have "The Old Way" to go on, as well I'm oldish :) However the Supertrapp tuning guide does mention the black carbon build-up as a running rich condition. FYI I get a fuel range readout of 340 KM with a full tank, not filled to the brim, just filled up so to speak, she has the std 17 (?) litre tank.

    Fatbat I'll get a copy of that manual, I have a couple of the Screaming Eagle ones, but they answer everything except what I want to know :)

    As a Marine Engineer and old petrol head I'm quite prepared to do the research and put in the time and effort to do as much as I can, eventually I will have to ride it some distance to see a good dyno guy, but I'll need to be able to tune it good enough to do the trip, which will probably be a bloody long way :)

    As I say I would gladly spend the $$$ on a good tuner to do it, but alas no one up here that I have any confidence with, maybe in Townsville, and I will want to do the cams first, still researching that one, SE 204's, S&S M103's, Woods 5-6 or 6-6..........yada yada yada....not sure how far I want to build it up too yet, probably end up with a 110 with CNC heads knowing me, but funds are tight, and I need to do it in stages like most people else I guess.

    As to "Tuners" up here there are only two choices in Cairns, and neither use a dyno, only wide band O2 sensors and road testing up to 100 KM/hr. or a little above maybe, and to compound the confusion both bag each others work, and I don't know anyone locally to ask for an independent opinion.

    Thanks for the input Robots, are you saying plugs still are readable with ULP ???

    The VE tables are pretty stable now, I have done nearly six or seven tuning sessions with up to a dozen runs (till the tuner is full), starting with the lower to mid RPM and throttle range and working up, and as to the AFR's I know the stock maps are covered in 14.6's and apart form the reported problems of running hot I read about they seem to go OK at that, I'm just trying to find somewhere in the middle, lean but not cooking the engine, even if that means 14.6 is OK in the low load parts of the map, I'm OK with that.

    I'll see what others say about your VE table suggestion, and maybe try it when I get back home (712 hours to go).

    My old map was close to that, and my new map is set at 14.6 at the cruise range, and I was happy with what I had running in it, and the bike seemed to run pretty good,  nice and strong acceleration once the revs get over 2300 or so and the stock cams start to do something, no hesitation or any issues on acceleration, no misses, no lugging on steady throttle etc.

    Ran hard to 156 kmph @ 4228 RPM when I ran out of handling and road LOL, engine temp was recorded as 135 degrees C at that point, engine temp is 130 degrees C on the steady 100 kmph runs, and 135 to 138 on the slower 60 and 80 kmph traffic parts, is that about normal temps guys ??

    However the Indy's comment about only going to 13.8 as the leanest AFR now had me a little worried, hence my post asking the Brains Trust their opinions about the AFR's, and a base number range to use, however I don't think my cylinder head temp was too high, no worse than it was with the older maps form what I can see of the recorded data sets I have.

    Cheers

    Ken

  • robots
    robots
    6 years ago
    absolutely plugs are readable, you get timing mark on strap, deposits on the porcelain, carbon or no carbon on the ring and if you move the VE numbers and go ride you will see changes to plug
    sure there no dyno in CAirns?

    search this forum as there is a thread on AFR tables which would be of assistance
  • Sunny Jim
    Sunny Jim
    6 years ago
    There are several views on efi tuning on Vtwins. Whilst Stoichiometric (lambda ) recommends the 'perfect 'afr is 14.6:1 , 
    These motors like a little extra fuel and a little less timing . They run smoother and cooler. 
    It does depend on how your motor is built/set up. 
    I use power vision and their closed loop target tune system . I run my cruise anywhere from 14 - 14.4:1. Depending on the weAther and the location. My fuel economy is good. At the end of the day the engine only uses what it needs. Getting your VE s equal is essential. 
    The ECU and the O2 sensors do their job well. Some prefer a set map In open loop. This works well also. 
  • Krash Kinkade
    Krash Kinkade
    6 years ago
    paulie I know a tunner that can read plugs no matter what fuel your using, he is a master at it.
    ken the afr under full load wide open throttle  should be at least 13.2 but if not riding hard , probably ok leaner. on street I doubt anyone puts them under full load for long. so a race tune a lot different to a street tune. tuners would probably do a race tune to give you best dyno numbers. but would be a waist on the street I'd say.
  • brash
    brash
    6 years ago
    I run my target tune cruise at 13.8 and high load cells at 13:1
    Much cooler for my 110ci especially in Sydney (ie traffic) A lot of it is to do with the 255 cam profile which is a heat generator. 

    Mileage isn't really a concern for me. Will net an easy 300km before the light comes on which is very pessimistic. 

    Remember these things are air cooled tractors. Fuel is good :)


  • robnicko
    robnicko
    6 years ago
    i use a powervision as well and have run autotune many times to capture the VE's as best as possible.
    My setup is pretty much stock except for the S&S Slip ons and S&S air cleaner
    I run a blend of closed (mainly cruise with CLBias set higher) and open loop and my engine temp is usually around 105-115 degree's, can go up in traffic , the most ive seen is 134 and then once moving again comes down. In these colder months Ive even see it drop down to 94degrees

    Consumption wise, a consistent 5.9l/100km

    The below video gives a good explanation of how after capturing the VE data to manipulate the VE/fuel/spark tables etc and although specifically for SE Tuners can be adapted to the powervision when running the WINPV client on a PC
    I have also manually manipulated the VE's as per the video below in part 2 near the end and am extremely happy with the end result.

    https://www.youtube.com/watch?v=tHvMJPVtqyE
  • Ken in Cairns
    Ken in Cairns
    6 years ago

    Thanks for the replies everyone, not sure if I am more or less confused now :)

    What are the CLB settings you refer to robnicko ?? Closed Loop bios, if so I can't find it in the SERT, is it the same as O2 Sensor bios?

    Also thanks for the link, I'll see if or SLOWCAST system will let me watch it.

    If I had the time when I get home I would play around with it some more, I might just try and do some more research and maybe load the old map back on, 14.2 to 14.4 in the cruise zone.

    The other parts of the map, especially the highest loaded parts are as they were, 12.8 in the 100% map column.

    I appreciate the advice, and even though some if it is contradictory, I would welcome more :)

    One more question, in closed loop does the ECM force the AFR to 14.6, even if the AFR table says say 14.2 ?

    Asking as the question was asked in another post, but wasn't really answered, from what I understand the ECM uses the AFR table (among other tables and data) so if the AFR table says 14.2 or 14.4 for a cell shouldn't it try and maintain that AFR if the RPM and MAP values correspond to the cell,  even in closed loop mode ? The 14.2 and 14.4 values are in bold in the SERT AFR table which means they are still in the closed loop range, if I'm understanding the manual correctly.

    If this is not the case I will have to bios the OS sensor in closed loop mode to get the AFR down but does that mean I can't have both the 14.4 and 14.2 that I want to run ?

    Cheers

    Ken

  • fatbat
    fatbat
    6 years ago
    Ken print out and read the TTS manual. Seriously, it will answer all of your questions and more and was written by the guy who developed the original Se tuner. 
    You don't put these ecms into closed loop mode. The ecm turns into closed loop mode when the af is set at the magic number that is discussed above. 
    Lots of tables to learn and all are important. 
    Have you considered buying the cams you want and installing them is Se Queensland and then getting it custom dyno tuned there? 

    The problem with home tuning is that the more you learn, the more dangerous you become! 
  • robnicko
    robnicko
    6 years ago
    Fatbat, is this the manual you refer to?

    https://www.rbracing-rsr.com/downloads/tts_tuning.pdf
  • Ken in Cairns
    Ken in Cairns
    6 years ago

    Thanks for the replies, much appreciated.

    I came across some of Steve Coles posts and I found them very informative, it looks like the last map I had was pretty close to what he was saying.

    So I might just tweak it a little and re-load it.

    Looking at the O2 Sensor range, 14.4 should still be in closed loop, even for the narrow band ones I have.

    Had a look for the bios in the SERT tuner software last night and didn't find it, I'll have a look through the manual tonight.

    You are correct Fatbat, fitting the cams down south and going to a good dyno guy down there would be the best idea, not sure about the logistics of it though, might do some sussing out this trip. Still have to decide which ones to choose, and my longer term engine mod plans :)

    As to dyno tuners in Cairns, there are a couple, all automotive, no specialist Harley guy, however one says they can do bikes, so might investigate them, but as has been pointed out there are only really a couple of places in Aussie that are really good. 

    I will get the TTS manual and go through it Fatbat. And yes the more you (think you) know the more you can totally hash it up :(

    Hence me asking lots of questions.

    We are heading out to do an Off-take so will probable be without any coms for a bit.

    Cheers

    Ken


  • Ken in Cairns
    Ken in Cairns
    6 years ago

    Looks like Lambda is a better way to go than AFR, as is allows for differences in fuel, which I will encounter on my trip, I usually only run Caltex 95, but a lot of the servos out west are BP.

    It also looks like it stays in closed loop at other values in a narrow band around 1, not the switched 14.6 in the AFR, and it doesn't look like the SERT has a Bios function, so hopefully if I set the table to Lambda it will allow me to set it were I want to.

    Have the TTS manual which I will read over the next few days, along with the SERT one again.

    It is not like it is a totally foreign concept for me, just a different application and software, all the modern diesels are ECU controlled now, but having some base numbers and safe parameters to work too is what I was after, and I think Steve Cole and some of you guys have given me that.

    When I finally work out what I want to do with this engine and how I'm going to take it there, one big build or a few incremental steps, I'll be shopping around for some advice on who to take it to for the dyno tune. I'll be ready for another big road trip by then I'm sure :)

    Cheers

    Ken