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Discussion Starter #1
Okay i just bought myself a Cobb Ap. I can do data logging but the problem is, I dont know what numbers my car should be at (how do i find out???) Plus some of the terms in logging i am not yet familiar yet with all of them. Where is a good place to educate myself on some terms and numbers my car should be at!!! I have cobb SRI, cobb AP, hks bov, Turbo XS FMiC, and a greddy catch can so far!
 

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The air/fuel ratio (AFR or A/F) should taper down from ~14.7 at idle/cruising to ~11 at high RPM full throttle / full boost. The knock retard (KR) should be 0. Those are the most important things to keep tabs on.

Oh also for the MS3, your fuel pressure should not be dipping too low (i think below ~1400psi is when people start to get concerned?) at higher RPMs.

What specific terms you're seeing are you unfamiliar with, which I didn't cover here?
 

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Discussion Starter #4
my boost is about 16.2 psi at 5000 rpm/ at 4000 rpms fuel pressure is 1739 and at idle it's 425/ knock retard is 0.3 only one time never saw again/ AFR is 14.7 at idle and 29.3 at full throttle (the more gas i give the higher this number goes?
now for the questions??/??????????????
-what is throttle position
-fan duty
-fuel inj. amt.
*mass airflow
-calculated load
*intake temp

words with this (*) symbol i dont know what the numbers should be at... (-) this symbol i dont know the numbers and i dont know what they mean??
 

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[quote author=Speed 3 Visionary link=topic=152513.msg3265105#msg3265105 date=1249511261]
my boost is about 16.2 psi at 5000 rpm/ at 4000 rpms fuel pressure is 1739 and at idle it's 425/ knock retard is 0.3 only one time never saw again/ AFR is 14.7 at idle and 29.3 at full throttle (the more gas i give the higher this number goes? an AFR of 29.3 under boost is practically impossible without blowing your engine... it should only go that high while engine braking with no throttle input. Should go down into the 11 (or even 10) range at full throttle...
now for the questions??/??????????????
-what is throttle position how far down you're pressing the gas pedal
-fan duty how much your radiator fans are spinning
-fuel inj. amt. how much fuel your injectors are spitting
*mass airflow voltage of your MAF sensor
-calculated load ECU-calculated magic number based on all of the other sensors' readings
*intake temp this is directly related to the ambient air temp and how much heat soak you're getting

words with this (*) symbol i dont know what the numbers should be at... (-) this symbol i dont know the numbers and i dont know what they mean??
[/quote]
 

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Discussion Starter #8
o lol thanks... What is a knock retard? because the car just hit 0.7 now. Plus if you say my engine would blow at 29 could the ap be reading AFR wrong or is there something that i should do? What could be causing this issue of such a high AFR... do you know a link that i could educate myself more on this subject...
 

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Knock retard is when the engine backs off the ignition timing because it senses a very small amount of predetonation. It's actually very common in this car and levels that low are nothing to worry about. Do you use 91 or 93 octane? It'll happen a lot more with 91.

The AFR... well I've never used an AP so yes it's possible that either it's using different units/the ratio is backwards or something else is wrong. There are calculations that need to be done to get an AFR reading in the typical ratio format most people discuss it in from the voltages that the AP reads directly off the factory wideband sensor.
 

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Discussion Starter #11
Okay ,, thanks you have been tons of help, what do you think my next step should be with AFR problem. The more gas i give the car the lower the # under 14.7 should go.. right now i am running way lean... not good .. i have been reading up on this.. 14 parts air to 1 part fuel ... so how the hell is my car not blowing up woth 29 parts air to 1 part fuel..... Is it possible,, as i drove the air mixture can shoot that high at some point??? Becuase the cobb ap locks in the highest #'s and that is what it locked in, no matter the conditions, whether im down shifting braking fast or what ever i did the mixture should be at those levels .. right??? any ideas what the problem could be??? very worried now..
 

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Discussion Starter #12
myms right now KR is nothing to what im flippin about.... i am getting readings of 29.2 AFR full gas. But my car does idle at 14.7.... what the hell should i do about this crazy jump in AFT. Im goin to check again maybe something is wrong...
 

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Yes, as I mentioned that's a normal AFR level to see while you're engine braking... the car cuts fuel in that case and relies on the fact that there's virtually no load on the engine and it can maintain its own momentum.

If you were actually getting an AFR > 18 or so while under hard acceleration, you would definitely feel some jerkiness and loss of power, even out of boost, and would be seeing much higher KR levels in boost. So it doesn't seem like there's anything to worry about other than you not being able to understand your AP 100% yet :)
 

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Discussion Starter #14
okay i am goin to check one more time to make sure but thank you for putting me more at ease i... you sound right as always.. and MYMS i have been trying to save my data log on ap but it seems to not save for me... trying to figure out why.. i saw i had 10 data logs on ap not from me.. i deleted them and am trying again.. once i get it i will upload it and post up for everyone to see... thank you guys for all this help...
 

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yea mine goes up to 29 when i'm off the throttle completely and down to 10 when on full throttle so I would double check to make sure your not getting them mixed up :] Otherwise you may have an issue but I think you would definitely notice in the way the car is driving.
 

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i seriously doubt you are seeing 29 AF except when letting off the gas.... Even though the ap maps were off for me they were still somewhat in the ballpark, so i seriously doubt yours are off by that much.

If you come to the meet tonight we can check it out and see what is what, and walk you through it. We could always hookup my daskhawk and log with that, then we can see instant results and know what is going on.

I would still recommend a custom tune because you have non-cobb parts, minnus the intake. So its better to get the car in check with a tuner.. i have a good one if you are interested.
 

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An AFR reading of >29 is means that the fuel is cut off completely (coasting).

The AFR is not really ~29:1 at all.
 
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