Bink

Anyone remember the LS1Edit mailing list fiascos?

Yes, I do remember a couple of them.

Do you remember the 5 gallons of gas to throw the PCM back to the High Octane table?? Fetumpsh was tenacious as a pit bull on dispelling that one.

Excellent, accurate and persuasive info. Thanks guys.

joel

Bill's 02 Z-28 SS

Hi Folks
I believe everybody is over reacting. Just because Team ZR-1 can tune with a narrow band O2 sensor (it works for him, OK) - what is everybody jumping down his throat. I took his information as I do everybody else’s - GUIDLE LINES, NOT 100% the only way to do something.
Before this creates a fire fight – I believe Wideband O2 is the best way to go but looking at the data of a narrow band O2 sensors – he has value to his argument. I decided to log some WOT O2 data. I have to tell you the data was linear and flat across the power band. I have to agree with everybody, that I am not sure what the AFR is with these numbers but if I could calibrate it, I could do some gross AFR adjustments. After 6 runs using 4 gears (I don’t want to go jail – it was fast enough) – my number was a ranged from .97 to 99 B1, .98 to .998 B2.
The wide band O2 gives you better resolution but the narrow band does give you some useful information to work with. We all should be open minded! If we don’t, technology will stand still and people with good ideas will tell the world but be afraid to share their information. Team ZR-1 I am using your information for gross adjustment. I do plan on buying a wide band O2 sensor for fine tuning.
Just my two cents.
Thanks
Bill

02RedHawk

iTrader: (17)

But you see, Bill, therein lies the problem - stock narrowband O2 sensors *cannot* be "calibrated". 910mv on one run correlates to an A/F of 12.8:1, but 10 minutes (or 10 days) later on your 2nd run 910mv can just as easily be 11.9:1. That's the sucky part...

Pay more attention to what your KR readings are than your O2 readings. The best way for you to do it without a wideband is to lean it out using your normal pump-gas until you start to see a little bit of knock-retard. Then, richen it up 1-2%, just to be a bit safer & accomodate some variances in pump-gas. Recheck often to verify you are not seeing any knock.

Fetumpsh

The following readings were logged using a WBO2 and EFILive.

O2 - 0.92V
WBO2 - 13.3:1

O2 - 0.98V
WBO2 - 14.1:1

O2 - 0.93V
WBO2 - 12.9:1

O2 - 0.94V
WBO2 - 11.9:1

O2 - 0.91V
WBO2 - 13.8:1

So, you guys make your own mind up if std O2 sensors are acurate enough

Nothing a NOS motor likes more than running at 0.93V, or was that, 12.4, or 11.2, or 13.9, or 14.bang!!!.....

Tuning by guess work, that's how it was done with points and carbies.

(Please note), those O2 readings are not EPA or GM approved.

S_J_H

I used to think stock o2's could at least be used as a "better than nothing method".
On my supercharged motor using a techedge WB with NTK sensor, I have observed A-F ratios dipping 2 full points down into the low 10-1 range while the stock o2's hardly even changed in output! I have a 9th mechanical injector I use and can load a lot of fuel suddenly at will to observe changes. The stock narrow band o2's are just about worthless for WOT tuning.
Steve

66ImpalaLT1

For what its worth, narrow band sensors are also affected by temperature and pressure at any reading other than stoich. So even if you "calibrate" it against a wideband one day, it will no longer be true when the weather changes.

Widebands are also affected by pressure, but not temperature. The effect of this is very small, but some units allow you to calibrate in free air to compensate for this.

Another_User

You could always continue to lean it out until your engine blows up, and then just add a little fuel ba...oh...too late. This whole wideband thing totally sucks. So how does the PCM figure out WOT...the force? (Which I might add is exactly how I plan on figuring out WOT mixture!)

Bink

"So how does the PCM figure out WOT" - Wideband and Dyno.

Predator

Using an EASE scanner, you can tune for maximum DELTORQ while keeping an eye on knock and timing. The O2 readings aren't even needed. You are actually tuning for the MOST POWER and not the "ideal" A/F ratio. When you've tuned for maximum power, the A/F ratio takes care of itself.

Maximum power, with the most timing, and the least knock and knock retard, equals the optimum tune. Tuning this way, O2 readings and A/F ratio are not a part of the equation.

It is NOT Team ZR-1 that is "close-minded."

Fetumpsh

Quick somebody call GM, Motec, Bosch.......they are wasting time and money with WBO2's, all you need is to monitor a PID that is nothing more than a 'calculation' of Torque, not measured.
Next thing you guys will be telling us is EGT sensors are a waste of time because the PCM can 'calculate' Cat Temps, it's gotta be close right??.


I dunno, you Ease guys do stick togeather alright.....

HumpinSS

iTrader: (1)

I wanted to reply to the assinine comment earlier but figured i would digress.

BTW ease isnt the only scanner to offer a "calculation" for figuring out DELTORQUE

deezel

I agree with several of the statements made in this thread. I think a little "misunderstanding of language" has contributed to some of the disputes...

The following are true statements (based on facts):
- Narrow band O2 sensors are not accurate except at 14.7 AFR (I have also confirmed this with my LM-1)
- Plenty of people have successful tunes based on KR and timing logs (no wideband, ignoring O2 sensors)
- Tuning a street car for drivability involves more than just fuel and timing at WOT.

One problem with narrowband O2 readings is the constant variation in their operating environment. Cruising around on the streets they get low-to-medium engine load and the temperature (at the O2 sensor) floats up and down with driving. A long highway drive will heat them up a bit more and keep a more constant temperature at the sensor. WOT runs get the O2s really hot for a short period, then they slowly cool back down.
However, even if it were possible to apply a temperature correction to the O2 voltage, the narrowband O2s will still be less accurate than a wideband because they are not designed to be accurate away from 14.7 AFR.

Finally, the original question of this thread... IMO it would not be a good idea to do *open loop* tuning without a wideband.

Predator

Of course everyone wants you to believe that you need to go out and buy that nifty LM-1, or buy dyno time, or drop a wad of cash at Johnny Rocket's tuning center.

EASE gives consistent real-world driving DELTORQ values that you can tune from. I have nothing to prove to anyone: my car's performance is all the proof I need. And the original post of this thread was asking if it was possible to tune without a wide-band, and the answer is unequivocally YES, which supports Team ZR-1.

It IS possible, but whether everyone here is able to do it with the tuning tools they have is a different question.

deezel

After my comment about misunderstandings I felt it necessary to clarify my last statement. Not trying to jab at anybody's tuning methods or say that a wideband is required for tuning.

It is my impression that the original question was about setting up a tune to run open loop all the time. I assume the original poster has a heavily modded engine to be interested in running open loop with no O2 sensors. IMO, for a heavily-modded motor it would not be a good idea to try and set up a *full-time open loop tune* without a wideband.

For stock and mildly modded engines, it is clear that many people can and do tune based on scan tool logs without a wideband. I did so on my own vehicle for over 6 months, and ran my best time with that tuning.

DAPSUPRSLO

iTrader: (14)

Thanks for all of the input guys.

I am running a cam only setup that consists of full bolt ons and a "sensor throwing off low vacumm producing" 230/236 107lsa 107icl cam. The car runs pretty good in closed loop but not 100% perfect. I figured on adding a set of the Edlebrock drag race headers that do not come with any o2 bungs and sooner or later will be going to SD tunning anyway so I just figured now would be a good time. I found a good deal on a WB so I will be investing and trying to tune with it via NoGo's equation in the next couple of months.

What about unplugging the 02 sensors. Doesn't the car still utilize the maf sensor but with no 02 values. Coundn't you just tune the part throttle by establishing how far your ltrims are off the desired 14.7 at part throttle and then just go about wot by monitoring knock sensors?

Team ZR-1

Common when someone cannot discuss something in detail they only can answer by getting personal and that image again show where an engine functions correctly is within the narrowband's ability but still a mute point since EPA, GM nor the PCM uses a O2 for high engine load so why are you ?

I hate to tell you but OBD-II Open LOOP where I come from is solely for cold engine start up anything after that is a sub set

Open Loop

When the engine is first started, the system is in open loop. In open loop, the PCM does not use the oxygen sensor (O2S) signal. Instead, it calculates the air/fuel mixture ratio from the TP, ECT, MAP/MAF, IAT, and CKP sensors (Figure 2-20).

The system will stay in open loop until the following conditions are met:

The oxygen sensor output voltage is varying, meaning that it is hot enough (600°F or higher) to operate properly and is sending a valid signal to the PCM.

The engine coolant sensor is above a specified temperature, which varies with individual engine application.

A specific amount of time has elapsed after start-up, which also varies with engine application. The specific values for these conditions are stored in the PCM’s Memory Calibration, which is calibrated to individual vehicle specifications.


Closed Loop

When O2S signal, coolant temperature sensor and time conditions are met, the system goes into closed loop. Closed loop means that the PCM corrects the air/fuel mixture ratio based on varying voltage signals from the O2S. An O2S signal below 450 mV causes the PCM to increase injector pulse width. When the O2S signal rises above 450 mV in response to the richer mixture, the PCM reduces injector pulse width. It is important to note that closed loop control still relies on all of its other inputs, in addition to the O2 sensor.

By constantly sensing the oxygen content of the exhaust, the PCM can maintain the air/fuel ratio at very close to the ideal 14.7:1 (stoichiometric) ratio. This is the point where the catalytic converter is most efficient.


Semi-Closed Loop: To improve fuel economy on some models, a sub-mode of closed loop is used. This sub-mode, called semi-closed loop, occurs during highway driving and light engine load. The PCM corrects the fuel leaner than 14.7:1 while continuing to monitor the oxygen sensor.

Converter Protection Mode: The PCM constantly monitors the engine operation through inputs such as the oxygen sensor, and estimates conditions that could cause the catalytic converter to reach excessive temperatures. If the PCM determines that a converter overheat condition may occur, the system returns to open loop, and enriches the fuel mixture which, in turn, cools the converter.


Acceleration Enrichment Mode

When the throttle is opened rapidly, or the vehicle is accelerated, the opening of the throttle causes a simultaneous increase in manifold absolute pressure (MAP) and throttle angle. The amount of fuel must be increased to compensate for the extra air. In response to the changes in TP and MAP signals, the PCM supplies longer injector pulses and additional pulses timed between the base synchronous pulses. Because the extra pulses are not synchronized to crankshaft position, they are called asynchronous pulses. This provides the extra fuel needed to prevent the engine from stumbling due to a mixture that is too lean.

Thus your experience of OBD-II has a different view as those of us who know what modes we are adjusting.

Bink

Once I went fishing with a 6 ft piece of line and a hook. No bait. I hung over a dock and caught 13 - 14 fish. True story.
What does this have to do with this thread?
My fishing technique happened to be successful due to very special circumstances. I wouldn't recommend it to anyone. It did work though.
Tuning Part throttle and WOT with Stock O2s and a scanner (NO Wideband) is alot like fishing without bait. Not very exact...but it might work....given the right circumstances.

The downside to fishing without bait -> no fish.

The downside to Tuning WOT with Stock O2s and a scanner (NO Wideband) -> no motor.

HumpinSS

iTrader: (1)

LOL@ Bink

Another_User

I second this technique. Although recommend not using the "force" as a tuning technique for everyone do I, work out sometimes it does.

02RedHawk

iTrader: (17)

Hate to point out yet another item where you're a bit misleading....but I will.

Your comment about GM not using the O2 for high engine load is only somewhat true. Yes, there is NO O2 feedback at WOT...but during R&D how do you think GM develops the WOT fuel maps that are programmed in our eeproms? WITH A WIDEBAND O2 SENSOR!

Once GM develops the proper fuel map to provide a correct A/F at WOT for their vehicles as-delivered to the showroom floor, there is no "need" for them to monitor WOT O2s anymore (up 'till recently it was very cost-prohibitive). Now, once we start modding our cars and changing around the intake/exhaust/fueling parameters, then it becomes increasingly critical for us to re-evaluate the programmed fueling using a WBO2.

By the way, ZR-1, its "moot".