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AFR numbers ??

17K views 33 replies 9 participants last post by  back n a stang 
#1 ·
Anybody running aeroforce gauges.....3.8 firmware? Just curious. but for those who are using aeroforce guage(s) and by chance are NA motor what numbers are you seeing under WOT? What are you around at idle? I am talking NA motors. With mine for now, I am running a agrressive 93-race tune and Borla "S" catback with X. Only performance mods. I have been building this car from the ground up so motor mods are not priority. I added the SOS/Dual Aeroforce gauges over weekend and still learning all the things they will do.

So if you are NA and know what your AFR numbers are at times post up. Like to see what others see.
 
#2 ·
There's not a lot of variation here. On a modern closed loop car like this, you'll see around stoich almost all the time until you lean on it more than 1/2 throttle or more than 4000 rpm or so, where it'll move to mid-high 12s.

I am on Procal but, the car behaved like this on the stock tune as well. I use a Dashhawk II for monitoring.
 
#3 ·
I'm seeing WOT briefly in 4th 10.94 once but a lot of 11.5 to 11.8...... just idle it's usually 14ish
 
#9 ·
The 2011+ 5.0's tend to like a richer mixture than previous Mustang years (N/A). We've found they make the most power around 12.0-12.3 Air/Fuel, assuming 14.7:1 is stoich.

It sounds like your GT is running a hair rich and could be leaned out slightly. I would contact your tuner with a few datalogs to have them make some minor adjustments for perfection. Other than that, your Air/Fuel seems to be very safe.

Hope this helps!

Shane
 
#4 ·
If you're seeing sustained numbers in the 11s that's way too fat for an NA car.

flashes of rich are not a surprise. 11.5 to 11.8 sustained is go back to your tuner and work on it some more. That's too much fuel and makes me suspicious about why they'd do that. You still have your cats in, right?
 
#7 ·
Certainly it is safe, no worries, gtstyles.

13 flat WOT, GE3G, is a bit hot for a heavily loaded application like this. I'd be happier at 12.6 or .7. Lean is mean, until something blows up.
 
#10 ·
The higher the first number in an AFR ratio, the leaner the fuel mix.

For example, I'm sitting about 12.6:1 on mine and the car is making about 440 FW horses through the stock airbox, cats and exhaust. I don't think there's much on the table here.

A consideration when tuning with AFR, is the use of ethanol-blended fuels. it shifts the stoichiometric point around a touch and means a touch of compensation if that's the fuel in your area. You need a richer mix depending on how much alcohol is in the mix as it has a lower stoich than pure gas.

This is why tuning with lambda instead of AFR is better, it's a ratio of mix to stoich and thus it doesn't actually matter what stoich is.
 
#13 ·
Wot at 11 is doubly safe. You're pretty much making destroyer smoke behind you to cover your license plate from prying plod:D. Your cats are getting a workout, that's for sure.

It is not unusual for this ECM to make adjustments. That's what it really does, closed loop all the time, not scalar/tables with a ho-hum, whatever MAF check and open loop at WOT crap like an EECIV, for example
 
#15 ·
Is your tune accounting for the no cats? If not, you are leaving power on the table with an overly rich mix for cat protection. Why you's accept the tune running that fat I don't know. That's black even on an FI application.
 
#16 ·
Its a safe tune. I drive it daily. 11 is what a lot of people run here. A cobra went 9.5 last night and has the same guy tune it that tuned mine. He puts nearly all of them around 11
 
#17 ·
This ain't some iron head in-line valve big block we have to drown in fuel to keep the head from from blowing through the hood with det. on pump gas.

Safe is fine but 11.0's ridiculous. You could EASILY be safe a full point higher on AFR, even FI. 12 is no problem whatsoever. 11's just going to suck a lot of gas, smoke, use up spark plugs prematurely and leave power and driveability on the table.

Be a different story if we were using direct injection but on port, 12-ish is a-ok.

Why don't you ask the guy why he feels he needs to run such a fat AFR? I'd be really interested in his reasoning.
 
#18 ·
My WOT consistently reads 11.9 every time with my 93 octane race tune. Well done Bama.
 
#20 ·
What source are you using to get your AFR readings from? Are the mods listed in sig: your current mods still?
 
#22 ·
don't make that assumption....independent verification with a better instrument is a good idea.
 
#23 ·
Eh i dont know man. I think id rather trust 1st party software over 3rd party any day. Unless theres some proof somewhere that Fords AFR readings are inaccurate, i still gotta assume theyre right.
 
#24 ·
Poblem is, that dash item is essentially a toy, built to a low price, without serious concerns re. accuracy of calibration.

A third party, purpose-built instrument is highly likely to provide better resolution, cleaner data and more reliable results.

many report the track apps toy to be off as much as a full point, if you look around the forums. not saying yours is but, a glorified idiot light in a factory dash cluster is not what I would rely on for tuning.
 
#25 ·
Poblem is, that dash item is essentially a toy, built to a low price, without serious concerns re. accuracy of calibration. A third party, purpose-built instrument is highly likely to provide better resolution, cleaner data and more reliable results. many report the track apps toy to be off as much as a full point, if you look around the forums. not saying yours is but, a glorified idiot light in a factory dash cluster is not what I would rely on for tuning.
Oh i would never actually tune a car with it but in terms of letting you know if ur running safe, it seems just fine. The dude from american muscle said their Bama tunes should be in the 12.0-12.2 range. Me being at 11.9 seems to be pretty darn close.
 
#26 ·
If its accuracy is suspect, how is it letting you know anything with certainty?

If you want to know the true speed a car is reaching, everyone knows you don't trust the dial on the dash. This isn't any different. The actual afr could be 13.0 or 10.9 for all the certainty the track app provides. It very well could be on the money but, I wouldn't rely on it.

I still think 11.9 is playing it way too safe on the car. Every car works differently and that's why canned/email tunes like this have to play it really safe like this. I think you could tweak that # up a bit, still have safety and pick up a bit.

My canned 91 octane tune from Ford plays it a little stronger on my car, hitting mid 12s WOT. The car makes 439 FW horses set up like that, according to my maths, with no other engine mods of any kind. It's been down the quarter over 100 times without problems both on cold days and broilers.
 
#27 ·
If its accuracy is suspect, how is it letting you know anything with certainty? If you want to know the true speed a car is reaching, everyone knows you don't trust the dial on the dash. This isn't any different. The actual afr could be 13.0 or 10.9 for all the certainty the track app provides. It very well could be on the money but, I wouldn't rely on it. I still think 11.9 is playing it way too safe on the car. Every car works differently and that's why canned/email tunes like this have to play it really safe like this. I think you could tweak that # up a bit, still have safety and pick up a bit. My canned 91 octane tune from Ford plays it a little stronger on my car, hitting mid 12s WOT. The car makes 439 FW horses set up like that, according to my maths, with no other engine mods of any kind. It's been down the quarter over 100 times without problems both on cold days and broilers.
Yea i agree, think id be alright with a mid 12 AFR. Its not like im boosted or anything but the safety of the 11.9 is fine with me.

I cant tell you for sure that its as accurate as it should be the same way you really cant tell me it isn't with out any proof. Until someone does a comparison test on a 13 or newer we wont kno. Doesnt seem like anyone has :/.
 
#28 ·
Actually, if you search around the forums there has been evidence gathered that the dash gauge is not to be trusted in this respect. I wouldn't be telling you this otherwise.

Here's a couple opinions on the subject from elsewhere, including BBR, who are pretty solid on Mustang tuning. This is a five minute google search of what I am talking about and have heard elsewhere.

How accurate are the track app gauges?

2013 wot AFR reading in gauge mode - SVTPerformance

Track app afr readings? - SVTPerformance
 
#29 ·
Actually, if you search around the forums there has been evidence gathered that the dash gauge is not to be trusted in this respect. I wouldn't be telling you this otherwise.

Here's a couple opinions on the subject from elsewhere, including BBR, who are pretty solid on Mustang tuning. This is a five minute google search of what I am talking about and have heard elsewhere.

How accurate are the track app gauges?

2013 wot AFR reading in gauge mode - SVTPerformance

Track app afr readings? - SVTPerformance
Seems like alot of people think its pretty accurate from those posts. I did a google search too and came up with the same. The one guy that had his reading 13.9 probably had some issue or it was operator error. The tuner shops are using sniffers out the tail pipe. How can that be more accurate than the wideband track apps if the gas has already passed through the cats? It looks like its still split. I ve had no problems with mine.
 
#30 ·
#31 ·
You don't calibrate a wideband for ethanol. The software in the device deals with this and with any dedicated gauge you can select this. Mine allows me to select whatever fuel I like and it's just to make sure the correction factor is applied to the outbound signal.

Most wideband devices don't read afr anyway. They measure lambda value, which doesn't give a **** what fuel you use and, then the signal is converted into an AFR reading that's displayed.
 
#32 ·
They aren't and even aftermarket gauges are not that accurate like doing livelink. Much better way to get better reading. Want better than that.... get on DYNO and let the preferred/trusted tuner do you a tune.
 
#33 ·
What it comes down to in terms of knowing what's truly going on, with absolute certainty, is sensor resolution and computing power. Low sampling rates and lag tend to blur accuracy on non-dedicated equipment. If the equipment can't process the data volume or do it quickly enough, it's very hard to be certain what's going on.

This is why every modern car runs widebands, as opposed to in the '80s and '90s when every car ran narrows. The sensor resolution and computing power wasn't there to run CL all the time and allow the engine management to be tweaked continuously in real time.

Most don't get how the engine management works on this car anyway. because of CVVT, DBW throttle and massive computing power, the engine can safely run seemingly dangerous lean AFRs under high load conditions and be in no danger. The adaptive algorithms, protection strategies and logic in the ECM are designed to handle this.

What we have here is the data is there but, the instrument isn't totally trustworthy, when we are talking the dash gauge.
 
#34 ·
Exactly and agree......The way and point I wanted to make
 
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