Air fuel code for scangauge

Modshack · 06-18-2010, 06:22 PM

Quote:

Originally Posted by Jordo!

Also, regarding fuel trims, note that there are most likely multiple trims --one associated with each cell in the fueling map (which you probably can't access) or at least a block of adjacent cells; cells are graphed by load (based on MAF value and known engine displacement) and RPM.

Short term trims (based on vacilations around 14.68 AFR / narrow band .5 volts) are averaged to create long term trims. One of those is probably carried into open loop (can Modshack confirm or refute that?)

The LTFT of +34 may or may not be a cause for concern. So long as driveability is fine, AFR's in WOT are fine, and the CEL light is off, it's not ideal, but acceptable (ideally, you'd want to have th ecar tuned so that these are all in the single digits and driveability is excellent).

Man, I can't wait to start playing with uprev on this car

I don't know how sophisticated Uprev is, but when I had the HP tuners program for my LS3 corvette virtually every parameter in the areas of fuel, timing, temps etc was programmable by minute blocks within the program. The chart below is the high octane timing table. Each block can be manipulated. You also had MAF scaling which, in conjunction with the logging function and a wideband A/F gauge, allowed very precise tuning. It's my understanding that the Long term trim corrections are added to the WOT fuel map. This is why the reported A/F's (with the correct SG readings) are slightly rich...
Rich is better (and safer) than lean but doesn't make quite as much power which is why custom programming will show increases.

JvKintheUSA · 06-18-2010, 01:11 PM

Transposed the 9 and the C. LTF trim is now -11, but I will have to do some driving. Off to the pool now for a quick dip. Thanks Modshack (+1) and JB1. This is a great forum with some great members!!

Modshack · 06-18-2010, 01:16 PM

Quote:

Originally Posted by JvKintheUSA

Transposed the 9 and the C. LTF trim is now -11, but I will have to do some driving. Off to the pool now for a quick dip. Thanks Modshack (+1) and JB1. This is a great forum with some great members!!

Great...Thanks!

-11% (rich correction) is what I seem to recall from my car when it was essentially stock. This is what got me going on the MAF tube experiments.
Remember, this is a "correction" and does not essentially mean your car is running rich. The 02 sensor reads the mix and sends appropriate signals to the ECU to correct the numbers to Stochiometric (14.7) through injector duration changes. It's a correction factor based on the results of the stock tune and flow. Watch the short term trims as well to see the instantaneous corrections. LTF's are built up over time. To clear them to 0, unhook the negative battery lead for a few minutes, and the adaptation will start anew..

Jordo! · 06-18-2010, 06:56 PM

^^^ thanks for that.

It depnds on the application -- richer (say mid 11's to mid 12's) is usally a bit better for FI (especially if nonintercooled or intercooling isn't optimal or only lower octane fuels are available...), but really it all has to determined empirically on the dyno.

Just took a gander ant the UpRev site -- looks like they offer full datalogging (cipher) and have full control over all the maps... but I couldn't find confirmation that they can tune VVEL.

Is it really true that even the uprev software can't tune VVEL on our car??? That seems like a huge tuning limitation if true

Modshack · 06-18-2010, 10:12 PM

Quote:

Originally Posted by Jordo!

^^^ thanks for that.

It depnds on the application -- richer (say mid 11's to mid 12's) is usally a bit better for FI (especially if nonintercooled or intercooling isn't optimal or only lower octane fuels are available...), but really it all has to determined empirically on the dyno.

Just took a gander ant the UpRev site -- looks like they offer full datalogging (cipher) and have full control over all the maps... but I couldn't find confirmation that they can tune VVEL.

Is it really true that even the uprev software can't tune VVEL on our car??? That seems like a huge tuning limitation if true

No problem...My turbo cars run from 10.8 to 11.5 under boost. Forced induction always requires more fuel as it is used to cool the charge and reduce potential for detonation..
I make a boost controller for Audi's that lets the cars boost safely to 24psi with a chipped program enhancing the fuel and timing. Without the chip, 18psi is about max...

On the VVEL tuning I could see a lot of guys really screwing up their cars. Be careful what you wish for....

Jordo! · 06-18-2010, 10:55 PM

Quote:

Originally Posted by Modshack

No problem...My turbo cars run from 10.8 to 11.5 under boost. Forced induction always requires more fuel as it is used to cool the charge and reduce potential for detonation..
I make a boost controller for Audi's that lets the cars boost safely to 24psi with a chipped program enhancing the fuel and timing. Without the chip, 18psi is about max...

On the VVEL tuning I could see a lot of guys really screwing up their cars. Be careful what you wish for....

10.8! IMO, that's a tad rich unless you are stuck with 91 AKI (or maybe a little too high a CR on the pistons...). Were you getting det leaner than that?

Eh... I'm used to tuning VVTLi on my old 2ZZ S/C'd Celica... (with TWO piggybacks working in tandem no less!).

Having more lift points to play with sounds like a bit of a PITA, but as long as one can see the OEM map as a base, on the dyno it shouldn't take too long to determine whether adjustments improve things or not

It's just the intake cam that gets adjusted, right? Not both intake and exhaust -- or are both adjustable? (Okay, that would take a little more time to get right...)

Modshack · 06-19-2010, 08:08 AM

Quote:

Originally Posted by Jordo!

10.8! IMO, that's a tad rich unless you are stuck with 91 AKI (or maybe a little too high a CR on the pistons...). Were you getting det leaner than that?

Ah, but remember....24psi. Not so rich when dealing with those pressures!

Jordo! · 06-19-2010, 08:52 AM

Quote:

Originally Posted by Modshack

Ah, but remember....24psi. Not so rich when dealing with those pressures!

Well, fair enough -- epecially if this was a general tune intended to provide an extra margin of safety for folks who wouldn't be tweaking things on their own

What CR were you working with?

06-18-2010, 01:11 PM	#2 (permalink)
JvKintheUSA Enthusiast Member Join Date: Jun 2009 Location: Canton, GA Posts: 465 Drives: 2013 Shelby GT500 Rep Power: 429	Transposed the 9 and the C. LTF trim is now -11, but I will have to do some driving. Off to the pool now for a quick dip. Thanks Modshack (+1) and JB1. This is a great forum with some great members!! __________________

06-18-2010, 06:56 PM	#4 (permalink)
Jordo! A True Z Fanatic Join Date: May 2010 Location: nirvana Posts: 6,394 Drives: 2023 NATM Rep Power: 419	^^^ thanks for that. It depnds on the application -- richer (say mid 11's to mid 12's) is usally a bit better for FI (especially if nonintercooled or intercooling isn't optimal or only lower octane fuels are available...), but really it all has to determined empirically on the dyno. Just took a gander ant the UpRev site -- looks like they offer full datalogging (cipher) and have full control over all the maps... but I couldn't find confirmation that they can tune VVEL. Is it really true that even the uprev software can't tune VVEL on our car??? That seems like a huge tuning limitation if true __________________ Enjoy it. Destroy it. Last edited by Jordo!; 06-18-2010 at 06:59 PM.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
50-75% improved fuel economy news story... 'supercritical fuel inejctors'	travisjb	Engine & Drivetrain	4	05-21-2010 11:54 AM
Fuel Filler Tube Coating Flaking Off Into Fuel Tank	SoCal 370Z	Nissan 370Z General Discussions	12	02-02-2010 10:37 AM
Takeda intakes and Scangauge info	JB1	Intake/Exhaust	11	01-26-2010 11:48 PM
Fontana Nissan -- Gauging Interest on ScanGauge Group Buy	Scott@FontanaNissan	Nissanraceshop.com - Supporting Dealer	20	11-23-2009 03:59 PM
gas cap and cel(SES) code	tru_Asiatik	Engine & Drivetrain	7	07-09-2009 11:38 AM