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Thread: Concerned and aggrivated

  1. #11
    Lifetime Member Whippled 496's Avatar
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    Quote Originally Posted by Delco View Post
    the VE table looks way out of whack for a whipple combo , the problem you are experincing is due to a couple of factors , one is the software never had a tps enrichment table like a pump shot , and the other is the amount of air the whipple forces in on the throttle crack.

    having tuned a huge number of whipple combo's I can tell you the low rpm VE under boost should have a huge lump in it whereas yours is a flat line - not what the engine is seeing.

    on toad tunign makes the VE table look very differnt to what the VE table looks like under steady state load on the dyno.

    Also when doing a boosted application like you have we alwasy use a boost referenced pressure regulator so we get a psuedo pump shot from the regulator on large map changes.

    it is not EFILIVEs CO3 issue but a GM coding issue really

    I have attached a example of what I would expect the VE tables to look like , do not use in your car as it wont be right but more for your interest
    Thanks for the input DELCO, like i mentioned before I realize my tune is not dead on by any means. All i know is that this phenomenon was not occuring when running the stock OS / MAF tune. The transitions to commanded AFR were made within 2 frames. Lean spikes did not occur until the throttle was released, opposite of how the COS tune works with the rich spikes when throttle is released. I had planned on getting the road runner to help with tuning the VE table because of just how difficult and time consuming it actually is to hit even 1/3 of those cells by driving around......especially in my area where the traffic is always terrible. Believe it or not, aside from a few stray cells, my BEN MAPS were within +/-.07 through out the majority of my standard driving range of the VE table. I know enough about tuning to see when something is wrong but no where near as much as most of you guys know, which is why i started this thread....maybe if the problem is with GM, then we could put our heads together to come up with a work around. If not, i was hoping like Justin has been mentioning, the enrichment acceleration tables could be added.
    Last edited by Whippled 496; April 2nd, 2008 at 03:52 PM.
    2014 GMC 2500HD RCLB SLE
    LML / Allison

  2. #12
    Joe (Moderator) joecar's Avatar
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    From the tune file it looks like you already have a boost referenced regulator.

  3. #13
    Lifetime Member Whippled 496's Avatar
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    Quote Originally Posted by joecar View Post
    From the tune file it looks like you already have a boost referenced regulator.
    Yes sorry, forgot to mention that, thanks Joe. It is a vacuum referenced return style fuel system with the regulator on the fuel rail.

    Why is it that these spike do not occur when using the stock OS / closed loop tune?
    2014 GMC 2500HD RCLB SLE
    LML / Allison

  4. #14
    Joe (Moderator) joecar's Avatar
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    I've been sifting thru my COS5 logs, and I don't see the lean spikes (I'm NA)...

    Are the lean spikes on tip in only occurring with boosted applications...?

    I remember seeing that hquick/Howard is seeing the lean spikes (he's got boost).

  5. #15
    Lifetime Member Whippled 496's Avatar
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    Quote Originally Posted by joecar View Post
    I've been sifting thru my COS5 logs, and I don't see the lean spikes (I'm NA)...

    Are the lean spikes on tip in only occurring with boosted applications...?

    I remember seeing that hquick/Howard is seeing the lean spikes (he's got boost).

    Not sure Joe, i know i do NOT have to be into boost to see the spikes though. Any positive throttle position gives me lean spikes. Here is a shot of a very slight throttle increase that results in the same lean spike. It happens whenever i press the pedal.

    Last edited by Whippled 496; April 2nd, 2008 at 04:36 PM.
    2014 GMC 2500HD RCLB SLE
    LML / Allison

  6. #16
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    Would like to see that doc , I have the GM calibrator tool for the early stuff with every calibration variable , all 4000+ of them , nothing that looks or documented as a pump shot or delta enrichment.

    Wall wetting calculations may allow it to be fudged though.

    Trust me Ross and I have looked for years as a transiant acceleration factor for rnleanment and enrichment would be great - especially on big cammed stuff and blown combo's

    Looking at that log then engine is lean for a long time after the throttle movement , I would be looking more at the mapping of the VE

  7. #17
    Lifetime Member Whippled 496's Avatar
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    Quote Originally Posted by Delco View Post
    Would like to see that doc , I have the GM calibrator tool for the early stuff with every calibration variable , all 4000+ of them , nothing that looks or documented as a pump shot or delta enrichment.

    Wall wetting calculations may allow it to be fudged though.

    Trust me Ross and I have looked for years as a transiant acceleration factor for rnleanment and enrichment would be great - especially on big cammed stuff and blown combo's

    Looking at that log then engine is lean for a long time after the throttle movement , I would be looking more at the mapping of the VE
    It just takes a little while for it to settle back and I am still working on dialing in the VE. The same engine parameters that result in a stoich AFR will result in a lean one after tip-in which makes AutoVE even more tough. Again, i realize my tune is not dead on yet....this does not change the fact there is a lean tip-in problem with this COS as represented by several other tuners here who's tunes are much more inline than mine is and have bunches more experience than i do. What i know is that it goes WAY lean everytime i hit the pedal....everytime......regardless of RPM, MAP, MPH, or what g/cyl is in the VE cells.

    Why do these lean spikes happen in the COS BUT not when using the 1bar stock OS/MAF tune?
    2014 GMC 2500HD RCLB SLE
    LML / Allison

  8. #18
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    I can't read your tune at work but I've tuned many Whipple and Turbo Trucks and never have a problem with a lean spike or richening problem. I use COS3 2bar,no MAF. I'm guessing the PE throttle position table is different than the way I set it.

  9. #19
    Lifetime Member Whippled 496's Avatar
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    Quote Originally Posted by slowhawk View Post
    I can't read your tune at work but I've tuned many Whipple and Turbo Trucks and never have a problem with a lean spike or richening problem. I use COS3 2bar,no MAF. I'm guessing the PE throttle position table is different than the way I set it.
    Well if you get a second to peak at it, that would be great!! If you can fix it, lunch is on me!!
    2014 GMC 2500HD RCLB SLE
    LML / Allison

  10. #20
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    Stop smoothing out the VE table!!!!tune it to what it wants.It will have hills,spikes and valleys when tuned in.

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