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Thread: VE - Wild VE AFR Swing Based On Oil Temperatures

  1. #1
    Advanced Tuner BigDaddyCool's Avatar
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    VE - Wild VE AFR Swing Based On Oil Temperatures

    So I've diagnosed an issue particularly with VE. MAF doesn't seem so effected.

    From startup, after driving for say 30-40 minutes when the cars at full temperature ........ The AFR swings massively once the engines oil temp finally climbs up above like 86 degree's.......

    at say 84 degree's it may range in the 14.7 mark, 87 it's running 5.3's, 89'c 15.7's, 91-94..... up into the 16's.......

    I've been looking at different compensating methods via transient impact and evap tables....... what happens with the merging of the maf and the ve correction factors in a mixed mode situation and so on.

    Now I haven't found a real full proof way around controlling it....... Does any of the more technical tuners have any other idea's here. I feel like i'm chasing my tail. The guy I had run a mafless tune up the dyno I dont think had a clue about this wild AFR issue.....

    It makes it rather difficult to tune at present, so what I'm looking for is matching the closest MAF or VE tune against the entire temperate board and then focusing on bringing each area to where the car idealy wants it but i keep hitting stumbling blocks......... eg. sometimes I might change something then the car wont run properly, claiming some weird TPS issue or something....... it seems like the Gen4's a bloody picky as hell.

    I cant just 'tune VE and MAF' and have it work. As it has a 20% swing ........ no matter virtually what I throw at it, I keep getting mixed results .......

    Idealy the end goal is to archive where the AFR's should be with what the car requests...... It's driving me nuts.

    Outside the transient tables, maf and VE.......... how else can I control it. Some things may bring the AFR's more inline but then effect drivabily due to swings either direction with EVAP or Transients etc......

    I looked at the manifold air temps, and all the various various with IVT etc to try and pinpoint a particular location to control it ...... I figure if I can get VE inline across the board and just retouch the maf it will work correctly in mixed mode closed loop.

    I've been at this a while now and I've only just worked out this massive swing and the fact it seems to correlate with oil temp ........ in particular. I did a standing IAT AFR test...... and it was fine, didn't get effected until over 54'c......

    So I've done my homework....... and now I'm looking at ways of nailing down the issue. Ultimately if there was a OIL TEMP multiplier for the custom OS for VE I'd have it sorted immediately but there's not.

    All my issues cant link to things I can control........ My only option is to use 'everything' to sort this out........ a little on each....... seems rather time consuming.

    A little transient impact/evap..... a little manifold air temp control, a little charge temp/bias adjustment, a little this that and the other.

    I can see why tuners go for 'maf' as it's the closest and most consistant.......... not to mention easiest....... but the maf cant deal with certain throttle response....... and hence this is where VE makes the magic....... so idealy i'm trying to archive how the car was intended to be used...... a mixed setup.

    Seems like alot of effort....... but I'd like to solve it, as it's bugging the hell out of me.
    2017 Toyota Kluger - 10.1" Android Custom Head Unit, Rockford Fosgate Speakers, 85kg Roof Racks. Prev: 2009 Cammed VE SS Sedan, DOD Delete, 210/218 550', RAMJet OTR, HiFlowCats, IQ System, Amp/Speakers.

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    I have used the injector flow rate vs IAT with some success for this. It must be iat temp, not oil temp that is effecting the AFR.
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    are u measuring actual oil temp or just the oil temp the ecu says, because the holden range dosnt have a oil temp sensor its just a calculation from the ecu, oil pressure and water temp...

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    Advanced Tuner BigDaddyCool's Avatar
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    calculation
    2017 Toyota Kluger - 10.1" Android Custom Head Unit, Rockford Fosgate Speakers, 85kg Roof Racks. Prev: 2009 Cammed VE SS Sedan, DOD Delete, 210/218 550', RAMJet OTR, HiFlowCats, IQ System, Amp/Speakers.

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    Mate,
    Reading you post your having some very strange problems that i have never heard of or experienced in my 8 yrs of HPT tuning ,
    Have you flashed it back to stock and see if it runs ok. I think i would be just starting from scratch and build a tune.
    Can you post your tune and a log of this as i would be keen to check it out

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    Advanced Tuner BigDaddyCool's Avatar
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    Quote Originally Posted by STATESMAN View Post
    Mate,
    Reading you post your having some very strange problems that i have never heard of or experienced in my 8 yrs of HPT tuning ,
    Have you flashed it back to stock and see if it runs ok. I think i would be just starting from scratch and build a tune.
    Can you post your tune and a log of this as i would be keen to check it out
    I will post up a stock tune with maf only with a scan tomorrow and you'll see via a histogram what i mean with the temp issue. As i learned today it seems to effect maf and ve.... I think ive worked out its coming down to transient tables........ impact vs evap over 156ivt
    2017 Toyota Kluger - 10.1" Android Custom Head Unit, Rockford Fosgate Speakers, 85kg Roof Racks. Prev: 2009 Cammed VE SS Sedan, DOD Delete, 210/218 550', RAMJet OTR, HiFlowCats, IQ System, Amp/Speakers.

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    From startup, after driving for say 30-40 minutes when the cars at full temperature ........ The AFR swings massively once the engines oil temp finally climbs up above like 86 degree's.......

    at say 84 degree's it may range in the 14.7 mark, 87 it's running 5.3's, 89'c 15.7's, 91-94..... up into the 16's.......
    You're likely seeing the effects of the IAT sensor heatsoaking, making it run leaner. Oil temp does not affect engine VE significantly.

    Heatsoak of fuel in the rails can have an effect too, but it's minor and there's nothing you can do about it. That's what O2 sensors and fuel trims are for, they fix up the few % errors that inevitably creep in at idle/low air flow/heatsoak conditions, even with a MAF. The MAF avoids the IAT heatsoak issue nicely and tightens up the tune a lot. 10% errors under low airflow conditions are the norm for SD tunes without careful consideration of IAT placement and lots of work on the IAT/ECT bias tables... MAF tunes you can get <5% error under all conditions then the O2 sensors do the rest...

    Just get the VE table close enough under normal, warmed up driving conditions (or put it back to stock) then turn the maf back on. The stock maf calibration should be close on a stock car, but you can tweak it if you want... you're tilting at windmills at the moment.

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    Advanced Tuner BigDaddyCool's Avatar
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    I dont have heatsoak from IAT as I already mentioned. It's either one of two things.

    1. General engine is hot, which increases evap overall etc.
    2. Injectors are hot..... and compensation is needed.

    So anyway........ I threw together the same tune with all the corvette gear....... bias tables, transients..... Now what that does is control things much better, however.. it's really rich at idle and the lean condition still exists partially in cruze zones........ nowhere near as bad, so obviously I can work on the transients and bias table to control it but it's just covering up whatever the problem actually is. I'd say it's probably something to do with injector flow rates at a certain temp.......

    It doesn't matter too much if my VE or MAF is out a little bit, because you can log the car from cold to hot......... and then compare the different temperate levels to see the effect it has over the both of them.

    I'm not interested in leaving my car run 14.7's until it's warm just for it to average over 16's........ Thats lazy and the drivability goes to shit and you can feel it......

    Others claim not to have this issue......... I checked for leaks etc, but this has been the same thing for me for over maybe 2 years I'ven never found on this car, surely others with OTR's have seen a massive swing in the air fuel ratio's....... from cold to hot, or do people just not check?....... blindly tune the maf/ve and go yep thats good here....... that'll do.

    The fuel trims compensate as you said but really to me they are a pain in the arse because they constantly drag the wrong compensation into the diff temp levels and then the car gets it wrong and on auto's screws the shifts a little as well as increases knock potential.

    ........

    Anyway I'm going to get the bias tables, transients all in check...... and just tune the maf and ve to what needs to happen to bring things into check.

    Basically I should be able to bring my swing of around 20% down to next to nothing really. My aim is for 4%..... Thats 'acceptable'. You need to remember all these factors effect WOT...... Have you done multiple runs of WOT against a MAF........ on the different temperature levels........ because there's the impact which is noticable on stomping the throttle but there's EVAP.... and thats noticeable if you know what your looking for.

    This is 'car tuning'.......... anything you can do to bring a car inline with how it wants to run....... = better drivability, better response.... I could be lazy, but I want to know..... because like most things, when you find out......... the next time you'll be 1000 times faster at fixing it.

    It's a hobby.
    2017 Toyota Kluger - 10.1" Android Custom Head Unit, Rockford Fosgate Speakers, 85kg Roof Racks. Prev: 2009 Cammed VE SS Sedan, DOD Delete, 210/218 550', RAMJet OTR, HiFlowCats, IQ System, Amp/Speakers.

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    Any luck figuring out what's causing this issue? I'm having the same issue with my c6 z06. I'm surprised no one else is having the same problem and haven't figured out a solution...

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    Advanced Tuner BigDaddyCool's Avatar
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    Quote Originally Posted by camONLYls1 View Post
    Any luck figuring out what's causing this issue? I'm having the same issue with my c6 z06. I'm surprised no one else is having the same problem and haven't figured out a solution...
    After much trial and error I have mine mostly fixed....... Is your maf or mafless? maybe post a tune and or can and i'll give you an idea of something to try
    2017 Toyota Kluger - 10.1" Android Custom Head Unit, Rockford Fosgate Speakers, 85kg Roof Racks. Prev: 2009 Cammed VE SS Sedan, DOD Delete, 210/218 550', RAMJet OTR, HiFlowCats, IQ System, Amp/Speakers.

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    mine uses both VE and MAF. It's a full bolt-on car (LT headers, Fast 102, ported TB, Haltech MF103), stock cam and stock heads. I recently restarted my MAF and VE tune because it started looking pretty ugly and I can't even recall which file was the best. I'll try and work on it later this week to clean it up a bit and post something up. Thanks for you help!

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    Advanced Tuner BigDaddyCool's Avatar
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    Quote Originally Posted by camONLYls1 View Post
    mine uses both VE and MAF. It's a full bolt-on car (LT headers, Fast 102, ported TB, Haltech MF103), stock cam and stock heads. I recently restarted my MAF and VE tune because it started looking pretty ugly and I can't even recall which file was the best. I'll try and work on it later this week to clean it up a bit and post something up. Thanks for you help!
    Honestly........ the answer for me was this.

    1. Charge Temp vs Bias......... (custom made....... not ripped off another tune)
    2. Rewrote the entire Dynamic situation to utilize the proper MAF/VE tables correctly and not compensate either direction the wrong way and set the VE Correction (MAF) to 1.0.

    So now I'm in mixed mode running 'much much better'.

    Ultimately the cars normally swing as they get hotter, the stock setup helps greatly reduce that........ (throttle speed etc), mafless is just terrible....... would never do it again on a car that originally came with a MAF.

    The MAP sensor is so slow and really thats why you get better economy and power if tuned correctly because its 'slow' basically. MAF is always going to give better response and be more accurate. You can improve the throttle response by just doing what you need to, to make sure the trims are always right or as close to.

    The idea of tuning the car 'just when hot' I now throw the notion out the window........... TUNE FROM 'FROM COLD TO HOT' eg. The car AFR wise should be the same virtually from cold to hot, if that is the case 'then all your bias tables' are 'correct'.

    There should never be 'heaps of variance' especially sustained variance from cold to hot.

    Thats my two cents. Hot and cold should report the same AFR variance, thats what you want to aim for 'first' and then dial everything in tighter.
    2017 Toyota Kluger - 10.1" Android Custom Head Unit, Rockford Fosgate Speakers, 85kg Roof Racks. Prev: 2009 Cammed VE SS Sedan, DOD Delete, 210/218 550', RAMJet OTR, HiFlowCats, IQ System, Amp/Speakers.

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    Quote Originally Posted by BigDaddyCool View Post
    mafless is just terrible....... would never do it again on a car that originally came with a MAF.
    Mafless can run well, but you need to get your transients dialled in. I don't notice any difference now running maf or mafless... and my trims are always under 2%.