Well things are coming together...

Very little knock, its all in the same spot so its simply a matter of an hour to play around and i can tune that out. Now im working on WOT tuning and im coming up witha bout .850mv at WOT, this seems a bit rich to me, given the fact that I scan so often I think I can lean it out a bit more under WOT so whats the most powerfull, yet safe? I need a target, 600mv? About 13:1 sound about right?


What are you guys making your most power with?

Also whats the most effective way to pull out fuel under PE.

Thanks

 

Don't use the stock O2 sensor for WOT tuning.

 

I'm going to have to

Without discouraging my efforts of what I'm trying to acheive with whats in hand right now, and realizing that some tuning is better than no tuning. I know what my 02 is telling me at WOT and I feel its slightly to the rich side, can someone confirm or deny what is considered to much fuel at WOT, and where I should aim for?

And the best table/array to do it in.

 

IF your going to do wot tuning the wrong way then shoot for 900-950mv.That way you dont blow your engine up.There is fresh post about that,I think.

 

Sorry, but all you'll do is cook your motor.
That's the silliest way to tune in the known universe.
Read the plugs!!!!!!!!!
If you're to lazy ot don't want to invest the time in plug reading, just remember that at engine overhaul time.

For getting enough information on making an intelligent desicion on this topic feel free to study up on the matter by reading the archives at DIY-EFI, and the eec list. There are some great papers out ther, explaining things in enough detail for any one to figure out.

Please investigate the matter before you roast an engine.

On a similiar note, you've spent how much in engine mods?.
And a WB at $180 is too expensive?.
You've lost me.......

I run an actual 11.8 AFR at WOT.
HTH
BTW, it's a turbo motor.

 

I dont question your knowledge grumpy... but sometimes I just dont get it


Basically you're telling me that letting the stock WOT tuning of the ecm do whatever it does is much better than me making an attempt at tuning it with whats in hand.... oooook

Even if (which I can't) I could afford a WB, I couldn't have it in time to tune for this week and this coming weekend.

Yes I can take plug cuts, but that doesn't tell me what my ratio is, nor does it tell me what my engine wants, a good reading plug doesn't mean the engine is making its best power at that ratio.

I know you guys have the knowledge but all the pros (I'm guilty too) are sometimes to quick to point people asking questions in the direction of spending more money instead of helping with whats in hand.

Just because I have a few expensive parts, does not mean that I just went out and dropped the bucks on it. This has been aquired over a VERY long time, through VERY hard work, and yes I do want to protect the investment, why else would I take so many data pulls and *try* to fix it with what I have?

Unless someone has a WB to donate, can maybe another member who hasn't posted give me at least a little experience/recommendations on what to do WITH WHAT I HAVE?

Thanks

 

The further "away" i shoot from .450mv (even to be *safe*) the less accurate my non-wb 02 sensor is going to be...


So given the direction I feel I'm being pushed, that theory makes no sense at all

 

On second thought...

Maybe I'm going about this the wrong way. Some of my combo is In the sig, most of the important stuff anyways, if you need anything else let me know. If you have excell and wouldn't mind I've parsed about a quarter mile (a bit short) pull at WOT. If you compare the mph to seconds (subtracting the seconds previous to 1mph) you'll notice that the engine seems flat out weak. I'd like to see if I can gain any power through tuning but to ME it looks fair (other than the one point it pulled out 7 degrees of timing) The total advance is somehwere around 32d which is reasonable.. A/F ratio previous to PE is reasonable, and PE is reasonable except I feel maybe a little to rich.


What needs to be fixed, and where is my power??? Am I right about WOT seeming a little rich or not.

 

A) I never said that, what I said was learn to read plugs. That is worth while, reading the stock O2 sensor is a waste of time.

B) You've had the car how long?, and now times is an issue?, give it a break, and forget this weekend, and get it tuned right first.

C) If reading plugs don't tell you you're AFR, you need more experience.
The only way to measure performance is to measure performance. That doesn't vary.


There is just no excuse for not using a WB. It just makes it so much easier.

There are lots of reasons *not too*. Some times you have to *just do it*.

 

A) I can read plugs, although I dont claim to be the best, I can tell whats going on, however when you live 30+ minutes from the track your oppertunities are very few, Its hard to find a road, accelerate for a quarter mile making all that noise, then kill the engine and pull over taking out a plug or two without the cops showing up.

B) I've had the car for a while, the new engine JUST finished its break in and I want to go to the track friday to find out what its got. I think its tuned good enough for WOT passes, however Right now im in the battle of the BEST possible tune. I ask to enlist help of people like you so I dont have to cover ground you have on things like the timing and WOT A/F ratio issues.

C) Reading plus doesn't put numbers on them, Only RICH, RIGHT, and LEAN, if you said 12:1 I'd know the appropriate hue to look for, if you said 14:1 again I'd know, but without a number I dont have to much to go by.


The sollution for not being able to take regular plug cuts do to society not liking you bombing down any long straight rode you can is your 02 sensor,sometimes you just gotta use what you got.

oh yea, I forgot one

D) Thanks

 

Well if what you say to A is true then all the more reason to get a WB.
Your not running a NASCAR engine with a Carb. You have DFCO, so there is no skewing the plugs in deccleration since there is NO fuel present.

I can't count the wasted engines I've seen guys figurin were close enough that a few passes wouldn't hurt it...

Sometimes, you have to work with society, being an outlaw will have dues paying involved. Gtech, and WB takes the tuning to 45 MPH for testing rather then 100+. One ticket and Bail for a 100+ ticket pays for a GTech, and WB most anywhere.

 

Pardon my ignorance but why is "rich" on a WB better than "rich" on a stock 02?

 

I said 950 so you dont try tuning wot @450mv or someting.There is people that has "nomally" seen 12.X a/f ratio in the 9XXmv range.So you would be close to that.But that really means squat if you want to do it right.Just find the w/b o2 from a junk yard.Then anybody could afford to do it.

Lets just say your dead on 128/128 w/ your tune.The pe% change f/a ratio vs rpm translated to a/f ratio would be 8%=13.52/9%=13.38/10%=13.23/11%=13.08/12%=12.94/13%=12.79.Have fun at the track

 

Someone point me to the WB sensor part number so I can see what it would cost me, and a kit.

I still feel there's a way to do it with whats on hand.. but none the less I'll see If i can get one at cost if its a sensor that your average parts store carries.

 

I have done lots of plug reading on my blower car that runs on
pump gas in the sig.
I have gotten alot of negative feedback about that ,alot of more experienced racers say it useless to try and read plugs on pump gas due to all the additives.
Anyone else think this is true?

 

Excuse my ignorance, but I'm pretty new to gm's efi. What would you get a w/b out of?? for easiest fit and so forth. Also, if its multi wire, how does 1 go about wiring it in(stock 87 is 1 wire). I know a few people at a junkyard, and could probably score 1 for cheap. TIA.
Bob

 

kvu, your formula for calculating the AF ratio (assuming a perfect 14.7 to start) is incorrect. If you added 100% fuel (doubled the amount of fuel), you should have an AF ratio of 7.35:1 (1/2 of 14.7). With your method you would have 0, which is wrong.

To calculate your AF ratio (assuming a perfect 14.7 to start) is as follows:

New AF Ratio = 14.7/(1+%increase)

The % increase is expressed as a decimal fraction i.e. 10% = .1

With small % Increases (under 10%) the difference is not much, but as you start adding more fuel, the differece becomes significant and you may think you are richer than you really are.

 

That's your formula glenn,it's from a post you responded to.

 

Then use my "new and improved" calcuation.

The other formula was "simplistic" and while reasonably close for small %changes, it is flawed on on larger fuel changes. It calculated the new AF as follows:

New AF = 14.7-(%Increase*14.7). With the "old formula" a "doubling" of the fuel (100% increase) will result in an AF ratio of 0 (impossible to obtain).

With the "new improved formula" it is as follows:

New AF = 14.7(1+%increase). A 100% increase (or doubling) result in 14.7/(1+1) = 7.35:1.

See the flaw?

 

Doesn't look like anyone ever tried to help you with your original question. Consider this, FWIW:

Last year I added a WB to my L98, and lined it out to about a 12.5 AFR +/- 0.1 (WOT) across the board, doing the fine adjusting with the PE vs RPM tables.

I went back and looked at the datalogs of O2 volts from the narrow band from the same tuning runs:

1. Using the 1-wire GM sensor, O2 volts went from about .920 to about .850 (linear) as RPMs went from about 2K to about 5.5K.

2. Using a 3-wire (heated) GM sensor, O2 volts were linear at ~.915 over the same range of RPMs.

That was my result from an SD set-up, don't know if it will help yours or not, but at least it's an indication of one possible outcome.

BTW, it was virtually impossible to get to that result tuning with the NB alone - only took an hour with the WB. YMMV

 

You're the man :hail:

I'm taking occasional plug cuts with my 1 wire 02 tuning and they go hand in hand, no detonation, looking a nice brownish/white with rich spots from decel and idles etc.

 

Kaiser, what did you get the 3 wire O2 out of???? I am wanting to switch, but dont know which one is bets. Also, how do you wire it?? is 1 wire 12v in, the other ground, and the 3rd a signal??? TIA
Bob

 

goneracin, there's a post on the tech/general board, a few days old from Vader, with info on how to wire a 3 or 4 wire O2 sensor from a 4th gen. fbody. Even shows you how to figure out which wire is the signal, power, etc.