so eric, riddle me this. you dont want to use a wideband that everyone tells you is the "only" way to tune with positive results, and you know that your "narrow" bands will only read a very small distance from 14.7 correctly, why not borrow someones wideband and log your wot and see what your 89 to 88 reading is? since your predator wont allow you to set your pe table up the way you want, and knowing predator they have leaned out your wot from the fat factory settings, it would be a good idea to know what it is cause even though your factory pe table is the same numbers accross the board, your ve table has lots of variance from 1500 to 6000 rpms and this should be changing that reading from the hit of the throttle to when you let out. i logged mine last night along with anothers vette and i logged a solid 12.3 from 3000 to 6500 and my o2's went from .889 to .904 through out the run and the vette's where .933 to .941 with a very small variance between 12.8 to 12.9.

 

I do want to use a WB. I don't want to spend $200+ dollars on one. I'm OEM except for the tune and E-85.

I'd love to "borrow" someone's WB to test with. There is NO ONE around Louisville KY to even talk to about this. I'm looking for car clubs. Everything around here is old rods and Studebakers and Edsels. My dad is in a club, he has a 28 model A and a 40 ford truck. I should look to the local vette club, or do they just pay to have it done. I Don't know a single person with any type of car that does engine building or tuning around here. It seems that most people are content to watch a ball game. This should be the place to find some hard data but no one wants to play.

I am considering paying to do some pulls at Automotion to test some things but I'm sure the dyno uses an up the tail pipe probe. If heat and backpressure have anything to do with a good reading how can this work?

???"since your predator wont allow you to set your pe table up the way you want"???. I have no complaints with the Predator. Or few anyway.

Your numbers and a good example of why I want to see a few logs. If your AFR was 12.3 and did not vary and your NBo2 was .889 to .904 that says a lot. It says that .90 is 12.3 and EGT and blah blah blah had nothing to do with it. But I am just taking your word for it. You are an honest guy, else you would not have told me your results, but most of the others are just NBo2 hatters. Why?

The vette's numbers may show the NB02 is reading EGT rather than AFR. I don't know, that is why I want to see some logs. A lot of logs, but no one will post ANY.
Did the Vette start at 12.9 or 12.8? We're talking about a change of only .01 mv here. Thats good enough for me. What will really tell the truth is a pull that starts rich and goes lean. I can set my Predator up for that and the o2 will follow it but I will not say it is accurate because I can't prove it. I can only say that they are consistent, changeable and repeatable.

Here is what I want to research. No opinions just research.

1. Do NB's follow EGT as the run progresses? Or AFR?
2. If they are following AFR is there a lag? How long?
3. Does the mv reading vary widely from car to car as between yours a and the vette?

I'm going to do this lean out test now and log it and post it here. I'll be back in 45.

 

2 pulls. Both 2nd gear A4. 1st from 25-80 MPH the other from 0-80 lugging second gear all the way. My interpretation of them coming up.

This tune was set to go 10% lean PE from 4,000 RPM up. You can see that happen.

1st pull, 22-83MPH

2500 RPM tip in .91 for .5 sec
2500-4006 started at .89 sloping to .91
4006-5614 .91 sloping to .89
5614-6400 .88-.87
lift off pedal .93 for .7 sec
This clearly shows the AFR going richer until 4006 RPM then a drastic turn toward lean.
Also shows tip in and as I lifted off the pedal it went from .87 immidiately to .93 for .7 sec.

2nd pull, 2-80 MPH second gear only. If you look at the log you can see where I stopped and turned around.

Didn't log tip in, Predator is slow to log.

2069-2527 .87
2527-3990 .90
3990-5151 .89
5151-5648 .88
5648-6168 .87

I have questions for you guys.

This 2nd pull the engine was under much heavier load. Would that cause the leaner than first pull .87 in the 2069-2527 range? Or is that an EGT error?

Other than that all the other RPM ranges show the same trends. With less than .01 diviation from 1st pull and the 2nd.

Going to go log a 10% rich pull.

 

Here is the next set at +10% PE.

Same as before, 2nd gear only pulls. The second pull is hard to see where I went WOT because I was accelerating at half throttle from 0-31 but it starts at 31 MPH.

1st pull 39-82 MPH

3221- .91
3372- .92
4024- .93
4444- .94
4664- .95
4883- .94
5419-6466 .93

2nd pull 31-87 MPH

2765-4111 .91
4111-6250 .93

In the first one you can see the AFR go richer all the way through 4883.
In the second one you can see the change at 4000 RPM, 10% PE.

In all four pulls the + or - 10% change at 4000 is clear.
What are you opinions about the NBo2's?

 

This is the way I actually run the car.

Is it normal for the engine to run leaner under heaver load?

Also, no matter how I set the fuel to richen up it still goes leaner as it moves from 4500-6500 RPM. Is this normal or should it be flat or richer as RPM increases? I.E. I can make the entire range run richer but I can NOT change the curve from increasing lean as it moves up RPM.

 

Getting a AFR of xx.x isn't really the goal is it. HP is the goal.
I doubt there is a HP differance in a 1 point or 1 % move in the AFR.


I never said that the WB is useless. I differ with those that say the NB is useless.
Too much of "only my way works and the rest are just stupid" around here.

I'm certain a WB is MUCH better. I wish I had one. But my $225 will be spent elsewhere, tires, groceries...., laptop, HPT, turbo....

 

There is a local f-body club you can check into.
They have a pretty good northern KY presence.
http://www.kyfbodies.org/

 

Here is a good reason for being a NB02 hater. http://www.innovatemotorsports.com/f...ead.php?t=3127
Shows the math behind nb02 operation.

 

I finally learned how to graph. Somewhat. These are 3 WOT only pulls with graphs that show how the AFR, PW, and NBO2's follow each other. If you point at the line it will indicate the value and RPM it was taken at.

I still need WB vs. NB data to determine the accuracy of the NB.

 

The only log to be provided. Cough some up guys.