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Monitoring ignition advance for all cylinders on piggybacks
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08-02-2011, 01:55 PM | #23 | |
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08-02-2011, 02:00 PM | #24 |
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He is running some Special Sauce Stage 2 from Cobb
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08-02-2011, 02:02 PM | #25 |
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Timing corrections I've seen are in the range of 3-4deg retard on random cylinders..
I actually have a log with no corrections at all on cyl1 while say 2,3,4 were retarding timing with up to 4 deg throughout the pull...all in a single 3rd gear pull... |
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08-02-2011, 02:04 PM | #26 |
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Is anyone STILL surprised here that piggies don't have full control over ignition timing?
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08-02-2011, 02:10 PM | #27 |
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OOOH! That's gonna upset some folks here. I distinctly remember certain forum vendors (Vishnu) particularly arguing how much of a difference a few degrees of timing do have on our engine. Your logs indicate up to 4 degrees difference of ignition advance between cylinders! WOW!
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08-02-2011, 02:11 PM | #28 | |
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I would love to see full cylinder ignition logs on a stock tune.
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08-02-2011, 02:46 PM | #29 |
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I have no reason to claim anything I haven't seen...it'll be available very soon to the general public through a free firmware download like all other Cobb AP updates..
themyst, i say you source an AP and start from there, otherwise you'll be asking others all the time nothing beats seeing it yourself on your own car my whole point is that CPS can't be "the" end-all solution to timing control...it is definitely a "form" of timing control, there's no doubt about that, but like the discussion about PPS vs PWM meth kits, it definitely leaves a lot to be desired in terms of "fine tuning"...part of the reason why I'm testing with Cobb now and part of the reason why I'm looking to replace my PPS meth kit pretty soon... |
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08-02-2011, 02:54 PM | #31 |
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08-02-2011, 02:54 PM | #32 |
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If this was on meth, Im starting to think the cylinder distribution argument holds water.
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08-02-2011, 02:55 PM | #33 |
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Fbo on stage 1 is easily a 13 psi tune.
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08-02-2011, 02:57 PM | #34 |
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It all depends on the amount of boost/timing (i.e. how aggressive) you have the tune setup...the more aggressive the earlier you'll see the cylinders "talking" (i.e. DME correcting timing)...This happens with/without meth depending on tune's aggresiveness...for example on OTS stg1 93 pump gas tune once IATs go high (no meth) you'll start more and more timing corrections applied across cylinders arbitrarily..
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08-02-2011, 03:01 PM | #35 |
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lol ok its a 13psi tune in your sense...i have to tell you that doesn't make sense as it doesn't target boost as you already know and the boost curve isn't flat and there's no reason why it "should" be flat...it targets load and depending on load it'll target different boost within configured limits/thresholds...
for instance on my car stg1 93 hits 15psi through midrange, 13psi at 5.5k rpm, 11psi up top..sometimes that boost will come down depending on conditions, sometimes timing on cyl1 will be corrected, sometimes timing on 3 out of 6 will be corrected, sometimes it'll never be corrected, all dependent on load targeted and conditions its running in... |
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08-02-2011, 03:08 PM | #36 |
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Yes, I am completely aware the AP uses the stock load-targeting logic.
My point is for an Fbo stock turbo car on stage 1, I'll be seeing 13 psi peak tapering heavily towards redline. I might fart on 14 psi if I'm doing a long sustained pull.
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08-02-2011, 03:11 PM | #37 |
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great, on your car in your conditions that time when you ran it that meant it only needed 13psi to hit the same desired load
in any case, i don't disagree with you, I'm just saying you're looking at it from a boost targeting logic and I can tell you right now in really hot/humid conditions it won't be a 13psi tune I have a feeling though now we'll move away from the timing discussion and go into a load vs. boost targeting approach to tuning and which is better LOL let's not...been there, done that many times... |
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08-02-2011, 03:16 PM | #38 |
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The logic is IAT based, suppress IAT and you can keep the boost down. If and when I run the Cobb stage 2, I'm considering running a DO1 nozzle strictly for charge temp cooling on a 50/50 mix; I bet a gallon will last me months! That'll keep boost at a reasonable level
Btw, no discussion needed about load targeting Vs PID. That's been beaten to death already. The possible cylinder-to-cylinder ignition variance, well, thats a new topic
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08-02-2011, 03:26 PM | #40 | |
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I believe IAT is the biggest proponent of the amount of boost required to hit load target. In a nutshell, have you ever seen the dme target LESS boost with high IAT on the stock tune? Both load targeting and PID have their pros and cons.
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08-02-2011, 03:31 PM | #41 |
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let's leave this for another thread really...probably one isn't even needed as the topic has already been beaten to death a bunch of times...you mention PID PID is there even with load targeting...PID control or controllers are in all kinds of places, here's a little wikipedia for your reference: http://en.wikipedia.org/wiki/PID_controller ... you'll see soon that the DME has a PID algorithm of its own otherwise shit would hit the fan very quickly lol
Once ATR is out you'll know/see/be able to modify everything to your liking..at the moment you can go by what they say today and choose to trust them or not...why would they tell you one thing now only to release it for you to modify later and find out they lied..wouldn't make any sense.. |
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08-02-2011, 03:43 PM | #42 |
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Shiv must be diligently writing an new beta update that includes includes ignition logging for all 6 cylinders which will be in the next beta firmware. ...but not really activated in autotuning till the beta firmware after that... LOL
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08-02-2011, 03:48 PM | #43 |
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Ok sorry. I was referencing PID as boost targeting because I am trying to be grammatically correct on a cell phone you're right.
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08-02-2011, 03:49 PM | #44 |
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He needs to publicly release the ignition flatline fix for the automatics first. Autotuning can wait.
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