I also have concerns on how any of the tuners will perform with an adaptive 6-speed tranny in the 2010.

I might add that I am interested in getting something to improve performance, but no one offers an explanation as to what any of the them do to keep the adaptives from overwriting the fueling changes.

 

The O2 sensors send a signal to the PCM, which is a simple voltage value. The PCM, in turn sends a control signal to the injectors. The tune that's in the PCM tells it what signal to send. It's pretty easy to "bend" this signal any way you want it.

Or, look at it differently. The O2 sensors don't really care what they see. They just report on it as a voltage. The PCM sees that report and "decides" whether or not it needs to take action. That decision is controlled by the tune (program stored in the PCM) and the tune can choose any voltage as the ideal value.

The process is probably controlled one of those two ways - I'd bet on the second one.

I suspect you are thinking the O2 sensors directly control the injectors. That doesn't happen.

Now, is a custom tune 50 State compliant? Maybe not. I know Edge's canned tunes ARE, because the emissions remain within limits (they might even be better under certain conditions). Edge will not allow its product to be custom tuned though, because then they cannot claim that they ARE compliant, since they lose control of the programming parameters. So, PHP, for instance, "rebrands" the Edge hardware as a Gryphon and then can load custom tunes on it. I don't know if the Gryphon is compliant or not, but I've never heard of a vehicle with a PHP tune failing an emissions test.

I cannot tell you anything about the other programmers such as the X3, because I don't have one and have not talked with Mike or Justin about them.

- Jack

 

Yes there is much more than just a fuel map and O2 reading that determines duration of fuel injector pulse, ambient temp, altitude, maf, etc...

I am somewhat amazed the amount of people that have purchased tuners and there doesn't seem to be an explaination of how they work or overcome this.

I am familar with tuning FI motorcycles and any tuner/programmer or ECU unlock program that is for a closed loop system comes with a bypass or means to shut off the O2 sensors to avoid trimming the fuel tables back to 14.75 to 1. Which this also makes them "for offroad use only."

I'll email some of the makers and see what they say.

 

They overcome it with the bias. By changing the bias (sample rate in one direction or another), they change the ratio, and this is only one of the many things going on to determine overall A/F ratio. Think of it this way, the O2 sensors are essentially binary devices indicating lean/rich. But a binary input doesn't mean you need to get a binary output. For example, modern 64 bit sound cards internally aren't 64 bit. They use a serial bus but clock it 64 times the sampling rate. The overall incoming 1/0 is then put through an averaging circuit which results in an analog output with a 64-bit range. By biasing the 1 or 0, you could move the output up or down the 64-bit range. The same is true of how narrow band O2 sensors are used as inputs.

Additionally, there's much more going on with the aftermarket tunes than just air/fuel ratio to achieve more power and driveability. The timing tables are changed to allow more spark advance, and the knock sensor advance/retard rates are changed to allow the system to achieve these higher rates without spark knock. The closed-loop to open-loop delay is changed as well (for instance, some F150 calibrations can take up to 3 seconds to switch to open loop after punching the throttle). If the tuner knows what he/she is doing, they'll also reprogram the VCT system for a different powerband as well. The Ford PCM also calculates torque reduction in various places (WOT, shifting, etc.). The driver demand tables can be changed to allow the PCM to deliver more power as well. This is just scratching the surface, as there can be literally hundreds of changes made in the tune to achieve better results from the engine and transmission.

The 6 speed... Ford's tuning of it, well, some of it seems that they either have strange motives, compromised and/or haven't had it out in the field in great enough numbers to refine it. For example, compare a 2004 F150 tune from Ford to a 2006+ and you'll see there are a number of improvements.

 

But an narrow band O2 is still narrow band. I could see changing the bias could get you down to 14.2 to 1 a/f ratio or .400 volts, beyond that an a narrowband O2 is not accurate. How to you maintain a/f ratios required for a set up like your Roush whistle? And how do the tuners/programmers remain CARB and EPA compliant?

Which wideband are you running?

BTW thanks for the responses, I'm not trying to be argumentative, just trying to sell myself on buying a plug and play tuner. I am used to having more control over mapping.

 

It really is covered in the document shown (as well as in countless books on EFI tuning theory). For example, if you skew 25% more fuel enrichments than leans, its going get it richer. Same in the other direction. And yes, it can be done in excess of the limited range of the O2 sensors because the computer moves the ratio up and down to see what the results are and is able to then calculate how much fuel is pushing the O2 reading to rich, then it changes direction and sees how much less fuel is needed to give it to read lean. Its does it rapidly and many samples, not one, are averaged to determine that X% fuel enrichment is resulting in Y% change in air/fuel ratio. Basically, a lot of averaging, and the more samples which are averaged the more accurate it gets even with 1 bit sampling. It doesn't need to be 100% accurate for cruising, just close. For wide open throttle the computer uses open loop and runs much richer (though open loop transition is screwed up in many F150 calibrations).

If that doesn't explain it well, do a Google search on 1 bit analog sampling. The technology is used in a lot of places these days instead of parallel multi-bit sampling when dealing with non-square wave-forms. There many good explanations out there which show sample data with charts.

A/F ratios for superchargers that you see on dyno pulls are open loop, not closed loop feedback, and the ratios are determined by testing and tweaking with a wide band. At part throttle positions it still uses closed-loop and runs at/near stoichiometric. The EPA doesn't measure A/F at WOT, and I believe the majority of states don't either. Most states simply look for a "passed" OBDII code from the PCM and many don't even put a sniffer on it. Here in Georgia, if I wanted to, I could simply go in an shut off anything in the PCM that's going to throw a failed code. In actual practice though, I keep them on and the truck is running cleaner than it did stock.

Custom tunes are not CARB compliant. "Canned tunes" may be compliant (either a certification or exemption) if the tuning company has submitted their changes to CARB. When that's the case, the usually don't touch cruising A/F ratios enough to cause CARB problems. If you want more control, then a hand held tuner isn't for you, rather.... tuning software is. Its going to cost you more, and has a steep learning curve. A hand held tuner is only going to give you very minor control over wide open fueling.

What wide-band do I have....? I have to laugh....not at you, but the irony of the question because I have 2 currently, have had others in the past and I'm reaching a 3rd now.

Current:
1. Autometer wide-band gauge with a Bosch sensor.
2. Innovate Motorsports LC-1 connected to a DashDAQ

 

DM - Three WB's...tell me that the voices made you do it! lol

I have been using an Innovate Lm-1 with XD gauge for 30k miles or so and it works great.

 

BIAS (EQUIV_RATIO) changes the final fuel calculation, you are not changing the way the HO2S respond.

 

I'd seen that equation and, of course, forgotten it. Thanks for reminding me, i.ride! Kind of explains everything, doesn't it?

- Jack

 

The BIAS tables (bank1 & 2) is load (rows) and rpm (columns). This is the calculation i use to convert commanded BIAS to commanded AFR.

Example Closed Loop Bias Bank1: RPM = 2000, Load = 70%; BIAS = -0.005004

Equiv_Ratio = (1 + BIAS) = 1 + (-0.005004) = 0.994996

Equiv_Ratio = 0.994996

Target Closed Loop AFR = 0.994996*14.64 = 14.567

But remember, just because i am commanding that target, I still need the maf transfer function to be correct first. Hope this helps expand on this.

 

Thanks for the responses. I am beginning to understand a bit better now. My tuning experiences are mainly with motorcycles that are speed density systems with no MAF which generally require the O2 to be shut off completely to correctly tune.