we had him calculate "real IDC's" and they were correct. and my Hybrid HHH actually does report "real IDC's"
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we had him calculate "real IDC's" and they were correct. and my Hybrid HHH actually does report "real IDC's"
where's the log?Quote:
Originally Posted by dpartinvr4
He did it himself, and he said he no longer has the logger.Quote:
Originally Posted by Forest Gump
lol, trust me man if you hit actual factual 100% IDC you hit fuel cut and it is like running into a brick wall.Quote:
Originally Posted by dpartinvr4
If you don't believe me go put 360s in and try to run 16 or 17 PSI, you'll see 100% IDC.
I"ve hit cut when my boost controller line wasn't reatached, i know the brick wall feeling, but if he's getting that much knock, it maked sense that his ecu is dumping in fuel to make the ratio richer and stop the knock, which is why over 100% makes sense to me.Quote:
Originally Posted by Forest Gump
but the ECU will not request greater than 100% IDC. The ecu requests a certain injector pulse width in milliseconds. The pulse width can only get so high before the injector is completely static, the ecu programmers were smart enough to know this point and the ecu will only request up until that point because as you said it is pointless to request more. The injector drivers cannot request more than 100% IDC, anything that reports that is either hugely overestimating or subject to rounding or measurement error.Quote:
Originally Posted by dpartinvr4
If you have logs showing over 100% IDC please post the pulsewidth and rpm, because in 7 years I've never seen a log like that posted where it actually calculated out to more than 100% IDC.
It has been turned into almost gospel on here that a 9b car can run 14-15PSI safely, but this isn't ALWAYS the case. Turn the boost down and see what the car does. It takes a very healthy car (no vss leaks, no oil consumption, clean cylinders, etc.etc.) to run that much boost on a stock setup safely.
Edit: let me further explain the logger thing a bit more. Even on an "accurate" idc calculator like HHH or manually calculating it you are depending on the rather slow speed of the ECU's protocol. Different values are "polled" from the ecu, so there can be some delay between say the reading of the RPM and the reading of the MS injector pulse width. What these means is they are not always EXACTLY correct.
I've never really paid much attention to IDCs anyway, as long as you do not hit fuel cut and timing advance is where you want it they really don't matter.
20 degrees of timing advance is actually a good place to be when you are pushing things on stock turbos, limited fuel, and small intercoolers.
I would reduce the boost until the knock goes away and not worry about it. You aren't going to see a huge power difference between 13 and 14 PSI on a stock setup anyway.
Yeah, I'm just going off what the OP gave us, we gave him the formula, and he told us they were right.....maybe he'll chime in here?Quote:
Originally Posted by Forest Gump
I agree with Forest, you can't exceed 100% Injector Duty Cycle. What I'm thinking is the logging software has some sort of delay in reading both Injector Pulswidth, RPM, and Timing. There's some sort of overlap that's not being accounted for. On a lighter note, maybe that's a tell tale sign of a problem and the loggers way of telling you the mechanical base timng is incorrect. The hall effect sensor is stating it's position as being set at correct base timing but it's infact an incorrect timing position so the actual fuel injection events are being calculated beyond actual engine cycles.Quote:
Originally Posted by Forest Gump
I completely understand that it's impossible to go over 100% IDC's theoretically. I've done the manual IDC calculation and it's still giving me 108%. Clearly I'm not calculating it correctly lol. I'll post my recent logs when I get home and maybe someone can help me out with that? In open loop, whether I run 12 or 16psi my IDC's, NB02's and Advanced timing do not fluctuate, they stay constant, and no knock. This is with a hotwired walbro and 52psi base fuel pressure.
When in open loop, I can understand that the ECU uses base maps and doesn't adjust for a rich/lean mixtures unless knock is present, at that point it just pulls timing. As long as I don't have a fuel controller I can't "trick" the ECU into thinking there's less air going in then there actually is. And as long as I have 360's, and no fuel control, my IDC's will always read high even though I'm running rich. Check out the "IDC for a several pre-selected injector sizes" on Stealth 316 - Injector Duty Cycle Calculation
I may just manually advance my timing taking this into consideration, and watch my knock closely ignoring my IDC's.
Thanks for all the info as well, very informative... I'll post my logs when I get home.
Why would you attempt to advance timing if you are having knock issues?
Jeff
Knock is no longer seems an issue, at WOT my timing fluctuates from 16-20deg. My ECU isn't compensating for the added fuel in open loop.Quote:
Originally Posted by kywhitelightning
you need a wideband to even know what your ratio is......
I'd be happy with 16-20 degrees on pure pump.
If you really care then yes you need to get a wideband, but you are probably low tens afr.
Here's a quick snap from my log at 16psi:
RPM 6231
INJD 114%
KNCK 00
O2 .93V
TMA 16
COOL 85.6C
AIRT 9.8C
INJP 22.7ms
A wideband would be nice, but the mods are done for awhile due to other responsibilities.
Not at WOT. That's the "open" in "open loop"Quote:
no, but your ECU reads your air fuel ratio, and will realize that it has to keep the injectors open alot less to maintain 14.7, and for WOT, you have the safc to adjust things so that you can tweak the afr to where you want.,
A wide band isn't "nice". A wideband is ABSOLUTELY ESSENTIAL if you are screwing around with fueling, either directly (with an AEM) or indirectly (with a SuperAFC or the like)Quote:
A wideband would be nice, but the mods are done for awhile due to other responsibilities.
It's a PREREQUISITE. A MUST-HAVE.
YOU MUST HAVE A WIDEBAND O2 SENSOR TO PROPERLY PROGRAM A SUPER AFC
Can I make this any clearer?
DG
an SAFC will be used at WOT becuase the ecu uses the Maf signal.Quote:
Originally Posted by DG
The SAFC is used at WOT, yes, but the O2 sensor is not.
WOT is 100% a lookup table of MAF vs RPM, with some small adjustments for air and coolant temp. That's it. There is no, I say again NO mechanism for the ECU to compensate for fuel pressure changes at WOT.
DG
As I've said in a previous post, I know all of this, it's pretty common knowledge. I also said I DON'T have an SAFC which makes a WBO2 a luxury at this point, not a necessity. IF I was tuning with a fuel controller I WOULD have one. Upping fuel pressure does not require a wideband, it's not rocket science here. Again, our opinions may differ, and I respect your input, but a lot of what you said has been repeated in this thread over. I have a good enough understanding about how our ECU's work to adjust fuel pressure and reap the benefits, I'm just looking to further understand some of the more intricate calculation methods it uses to control timing.Quote:
Originally Posted by DG
OK, let me restate:
YOU MUST HAVE A WIDEBAND O2 SENSOR IF YOUR ARE ADJUSTING FUELING THROUGH ANY MECHANISM, BE IT CHANGING INJECTOR PULSEWIDTH ELECTRONICALLY, OR MECHANICALLY VIA FUEL PRESSURE
We keep repeating this because you don't seem to get it.
We are trying to help you out. There are cumulative DECADES of tuning experience here in this thread.
DG
DG, please don't take my responses in a derogatory way, I completely understand what your saying. Many of those who have posted on this thread I'd consider "experts" in the platform and hold their opinion highly, I've been around long enough to know who they are, you are among them...Quote:
Originally Posted by DG
What I'm saying is, this is the situation I'm in, right now a WBO2 is not an option for me. I understand I need one when dealing with fuel changes, but instead of reminding me of that, give me more constructive feedback based on my situation... Would you recommend I bring FP back to 43psi or what would be a safe baseline?
From the recommendations of other respected 3S tuners, I was told bumping up the pressure won't hurt. Since I did so, the car runs considerably better at WOT, have zero knock issues, and timing is still in check. From my personal experience, I have seen no ill effects of the changes made.
Honestly? I'd reset everything back to stock until you were capable of affording the right tools.Quote:
Would you recommend I bring FP back to 43psi or what would be a safe baseline?
Maybe I'm pounding on you a bit hard, but there are like SIX threads going on where guys are trying to tune without using the right tools right now. That was understandable 15 years ago when we were all learning... but these days when tuning information is all over the Internet?
This is a lesson worth learning early, so you're on the receiving end of some tough love with the hope that the next 20 guys will read it as well: doing it right up front ALWAYS trumps doing it half-assed and trying to work around the incidental problems. When we are talking engine upgrades, that means purchase #1 is a wideband O2 sensor. It is the prereq for doing boost increases, fuel pressure increases, and injector changes, and it's not a bad idea for exhausts and intercoolers too. If you can't afford one right now, then you cannot afford engine modifications yet.
DG
turn the boost back to stock, you can leave the fuel pressure, its not going to hurt anything being up, keep an eye on knock. THis is the wideband I have, It's VERY affordable, and has everything you need to keep CEL's away, and provide data to a logger.