A WB controller needs to know what the stoich AFR is. It always knows what lambda is, the reported AFR is a calculation from lambda.

Our TT-1 WB controller setup utility has an entry for the stoich AFR. As the controller needs to know this for the fuel that is being used.

There are many ways to go with this. Even running E85 one can use gasoline AFRs. And tweak the extra 30% more fuel via the BPC or fuel injector constant. Otherwise the VE table will max out trying to add the additional fuel.

Or, change the TT-1 WB set up for the proper E85 AFR, and change the EBL ECM AFR tables to E85 values. Same as above, it all drops into place.

All depends upon what stoich AFR you want to look at...

RBob.

 

This is very good question. Likely one reason I've not been successful using WB (with controller) to tune my E85 setup better.

My WB has ability to set targeted AFR, and output voltage. And I'm able to fine-tune EBL to correct slight offset in that voltage. I'm still little lost how to do this correctly...

I've used to date following: figure out WB voltage range to be used, then set WB for 14.7 AFR (fixed voltage), offset correct that range in EBL WB configuration (to make it show exactly 14.7 AFR), then set WB controller for that voltage range.

I've not changed anything in EBL calibration. Used spreadsheet to change AFR maps from stock to E85. For tuning with WB disabled BLM and highway lean mode. All I get is 12 numbers in mostly closed throttle / decerating VE map area.

Because of that I've been using heated Bosch NB and highway lean disabled to date.

 

Bearing friction is a wash with an idler. About the same.
Windage, and rotor inertia, really can't be eliminated easily, but they're really not much.
Oil in the main bearings takes considerable more power from the engine than does the alternator in any configuration.
Actually, rotor inertia is only a factor when the RPM is changing.

Power is power, whether measured in watts, horsepower, or BUT's.
There are 746 watts per horsepower, regardless of the alternator speed.
Varying the pulley changes the mechanical conversion like any transmission, allowing the engine to turn in its preferred range, but that doesn't change the real power required for the alternator to produce output.

Nothing to speak of, until you start seeing misfire.

That was in my younger days.
Something upwards of 8 grand, with stock pulley, so the alternator was spinning something above that.

 

Do understand what Rbob is saying here, and it should all make sense.

An O2 sensor, wide or narrow, reports lambda. Neither too much, nor too little oxygen left after the burn. Lambda is 100% burned both O2 and fuel. The perfect stoich ratio, and theoretically the maximum heat output from that fuel.

The sensor itself doesn't care.
It will report Lambda, at whatever voltage represents Lambda, when the stoich ratio for that fuel is achieved.
For a narrow band, that voltage is 0.45somthing. Higher voltage is more fuel than stoich, and lower voltage is less fuel than stoich. That's all.
For the wide band, it depends on the conversion in the controller. The controller knows at least five points ( and good ones a lot more ) and generates an output based on the calibration of how much deviation from Lambda is how much voltage to output.
It's not linear !

Note that I did not mention an AFR !!
That's because it doesn't matter.
If you're running gasoline, that ratio is something close to 14.67:1 AFR by weight.
If you're running nitro-methane, then it's something close to 1:1.
The AFR is calculated from the voltage deviation from the value that represents Lambda.
Because AFR is a calculated value, it works for any fuel ( including wood ) once the ratios are known, and the calculations ( table entries in the EBL ) set up.
For the narrow band, there is no calculation. Only "more" or "less." Anything else is a best guess.

Personally, I recommend not using a fudge factor to correct for anything, so that your tables, and WUD, always reports what really is, and allows a minimum of thinking to interpret ( or mis-interpret ) what it's telling you. ( but that's me )
It's MUCH easier ( and far less time consuming ) to spend the time to initially set up the appropriate numbers and tables in the first place. ( how do I know this ? )

 

Basically I was just curious on doing a small comparison of UDP vs. the cutout switch concept..
Bearing friction in an alternator will be different from an idler IMHO because of the load on them, friction of the brushes/slip-ring, etc but let's not get too much into unnecessarily nitpicking details here At any rate, there's a diagram on page 21 here for the full idea http://www.delcoremy.com/documents/h...ite-paper.aspx (note: diagram only till 6000 rpm alternator speed.. mind the belt drive ratio). I was looking at this at work a while back but my brain already dropped some details..

With friction and windage not too big your cutout switch idea would seem legit indeed ..even more so if, as you pointed out, there are no real drawbacks from a short run on battery power only!
Of course internal engine friction and pumping losses are a lot higher than the alternator or any other engine accessory would bear.. On inertia, yeah well since we are talking about engine acceleration I was assuming a transient process with changing RPMs hence I mentioned inertia But yeah just a small amount here either.

Think we missed each other a bit on this. I was merely distinguishing between electrical (alternator output) and mechanical (engine output and hence alternator input) power, and the conversion factor (efficiency, eta). And this factor changes in regard to load and speed. There's also a figure showing an efficiency map in the Delco-Remy white paper linked to above if you want to look at that (page 24).

Ok, so no problem for a drag run then it seems. What about fuel pump voltage? Other than that, I only had the control electronics and ignition in mind.

Upwards of 8 grand, i see.. nothing to worry about then. Btw typical alternator belt drive ratio is somewhere around 2 to 3 btw, so I dont blame the alternator for grenading at like 20+krpm

 

So basically you're saying in a gasoline engine stoich will read lambda = 1 and 14.7:1 AFR, but also lambda = 1 and 1:1 AFR in a nitro-methane application?
I take it the WBO2 has the advantage of measuring Lambda over a linear scale, unlike NBO2 sensors; then calculate AFR from Lambda? Then how does a WBO2 calculate AFR, providing mass of fuel used (as you pointed out, AFR is by weight) is unknown?

 

Correct, and for E85 Lambda of 1 is an AFR of 10.4:1

A WB O2 sensor is not linear. Some controllers such as the DIY_WB, early FJO and Zeitronix output a non-linear voltage versus AFR. Need to use a look up table to convert the voltage to the proper AFR.

When the voltage output versus AFR is linear, it is the controller that does the work.

RBob.

 

So e.g. to use a WBO2 with E85 you would need to tell the controller that Lambda 1 is not 14.7 but 10.4:1 AFR??
Yeah right on the non-linearity.. I remember now ZT having an earlier model like that.

 

My WB currently reports lambda. So any fuel used when at stoich will read 1.00. I run E10 but controller previously used A/F set to 14.7 for stoich. I will see 14.7 when using E10. I should reset it to 14.13. If I were to run E85 it would show 14.7.

WB reads unburned 02 BTW.

 

So if you are running E10 and your bin is setup (stock) for 14.7, when in closed loop is it actually commanding to run at 14.7 or commanding lambda (in our case 14.2 because we are running E10).

I guess what I am asking is, if I am running ethanol blended fuel (everything up here is up to 10%), should I setup closed loop so it is actully commanding the correct AFR for the fuel I am using?

 

You can change the stoich AFR to 14.2, note that you will need to either lower the VE tables or the BPC vs VAC to compensate. Otherwise the BLM will drop to do so. If you do make this change there are some other tables that should also be changed.

Such as the crank, PE, highway, and open loop AFR tables.

Then if you are using a WB for VE Learns, it too needs to be set up for the different stoich AFR.

RBob.

 

Would you not need to increase the rich lean median values for swing points say 5% higher as well?

This was discussed in another thread about 5 years back that I may have started.

Can the NB 02 sensor actually be fooled (for lack of a better word) to command other than stoich? Recently that thought came to me!

 

I'm totally lost on this one.. I can see how lambda will be 1 when stoich, ok. But I take it the WB controller calculates AFR from lambda, so this means the weight of fuel must be known to relate any excess oxygen or fuel to the corresponding AFR, no?
Thus lambda 1 / stoich would be a different AFR for pure gasoline, E10, E85 etc.

 

A/F is different as you state for each fuel. 14.7 or 14.13 or 7.xx( or is it 9.?xx) for E85.

They will all show 1.00 Lambda on WB. If WB controller shows A/F rather than lambda which is user option and is set for 14.7 for stoich and you run real gas vs E10 they will both report 14.7. UNLESS you reprogram controller for the A/F of the fuel you are using that day. Lets say it a programing function of controller to show you what you expect to see.

As you are aware the sensor reports un burned 02. If it is all consumed 02 that is 1.0 lambda is the result.

maybe the "weight of fuel" is important? I am not sure. The alcohol in E10 molecular composition may be such that it uses or releases more 02 as it combusts thus A/F for stoich is different. Pure alcohol say methanol burn may use or release even more 02 thus a very low A/F of 6.x/1.

 

good point on the oxygen release/use with different fuels..
anyways, let's say it shows lambda = 1 and AFR 14.7 for real gas as well as E10. What does it show for E85 at lambda = 1? And what does it show for say lambda 0.85? I'd guess that value would be different for every fuel type thus I dont get why you said you should reset to 14.13 but still it shows 14.7 for stoich.. (i guess that would be the real AFR composition to achieve stoich on E10 then?)
sorry can't wrap my head around this one just yet
and btw my ZT2 LCD for instance shows lambda as well as AFR.

 

When I had first purchased my WB I believed it should show 14.7 for stoich CL when all was good in tune. It in fact did (+or-). I was pleased. My tune was A-OK. Then I realized I was in fact putting E10 in my car that is 14.13 not the reg gas that was non ethanol. Yet my WB shows 14.7/1? Now I was not so pleased. I thought I needed to change my rich.lean.median settings for 02 sensor. I posted the Q at Innovate site and I recall they said to change the controller to report stoich at 14.13.

If WB set to report 14.7 as stoich I believe would show 14.7 when set to A/F. I will fill up tonight with E85 and report back.

I believe the only thing a WB reports is lambda. It then uses a calc in controller to report what 1.0 Lambda would be in A/F term for fuel you are using if you elect A/F readout. You need to tell it what fuel E10=14.13 reg fuel=14.7 for when all the fuel consumed.

 

you see the point i'm getting at is like when you said your tune was fine on E10 despite the WB reading 14.7, i'm wondering if the E10 cAFR shouldn't be really 14.2 then?

what you described basically means the engine would run fine with an cAFR set to 14.7 and the WB reporting 14.7 - although both should really read 14.2 (lambda = 1 with E10). does that make sense? ^^ one discrepancy would offset the other, kind of.

those rich/lean/med values you're speaking of.. is this a WBO2 controller setting or something for the PCM NBO2 CL control?

 

I believe the NB02 sensor also moves A/F towards stoich whether it is reg fuel or E10. I believe my tune in bin (constants)was at 14.1 for stoich at that time. I believe I moved the lean rich meadian all higher about 5%. I may not have had to and should not have moved rich lean median. Those are the volts boundary limits in tables the 02 swings over. Yes in PCM NBO2 CL control. I actually was trying to command a richer A/F and unknowingly may have moved it to what is correct for E10 as far as commanded stoich. Not sure on that as it was 5-6 years ago. I purchased WB about two years after my intro to tuning 101. I never changed the 14.7 which was factory set by Innovate at controller. I should have moved it to 14.13 and then I would see 14.1 in CL stoich and Lamba when set so at 1.00.

Bottom line is when set to 14.7 in controller Stoich is 14.7 and Lambda = 1.0. when set to 14.13 in controller stoich is 14.13 and Lambda shows 1.0.

I would think of it as a set up of reporting A/F values for fuel used.

 

When you change the swing voltages you change the mixture, regardless of sensor type.

We try to light nitro @1.7:1 afr.

 

I just installed the 48lb bosch 3 injectors from FIC and starting to tune over with the ebl with the new injectors.
Attached is the data that they provided; looks like from ls bins.
The last chart looks like the most sensible looking numbers for injector offsets however it also has a kpa column, not just volts to miliseconds. (That last table does go up to 18volt across the top column however in converting it chopped it off.)
Any ideas on how to translate this data to our injector offset?

 

Use the 0 row that is in red. That is for when a VRFPR is used. Use the Small Pulse - B4005 table for the "INJ - Small PW Correction table."

Any chance you can post the rest of the last table and the Bosch part number from the injectors.

RBob.

 

RBob,

What's ur comment on using EBL to run a B2K Callaway Corvette?

 

I need more info on what kind of set up the engine/vehicle is.

RBob.

 

OK, a quick 'net search shows B2K as being a GM RPO code for a Callaway set up Corvette. I can easily see an EBL Flash running a '87 - '89 vehicle, and the EBL P4 Flash running the '90 - '91 vehicles.

But once into the LT1+ cars it will be more difficult to use an EBL Flash system.

RBob.

 

RBob,

Yes. Predecessor to the LT-5 ZR-1. L98 based twin turbo. MAF based. Friend has one and having issues w tune due to inop microfueler. They don't appear to be available any longer. The car is an 87 I believe. My thought is that with EBL VAFPR control, you could eliminate need for microfuelers. Thoughts?

 

The microfueler is likely no more then either a FMU or aux injectors. Best bet is to size the injectors for the generated HP, get rid of the microfueler, and use a EBL Flash ECM with the Port Mod. Oh, and a 2-bar MAP sensor and eliminate the MAF.

Lots of L98 and LB9 MAF engines running the EBL Flash ECM with the Port Mod and a MAP sensor.

RBob.

 

Pretty much what I thought. Thanks RBob.

 

Would it be better to use the simulated NB from the WB controller or is running a stock NB O2 ok?

 

Use the stock NB O2 sensor for the ECM closed loop input.

RBob.

 

Just a curiosity why no code to allow the wideband to provide closed loop fueling under all conditions? My 2012 Titan uses factory widebands to monitor the air/fuel ratio and adjust for varying ethanol percentages and uses the downstream narrowbands for closed loop fuel trims.

 

Thank you!!!!

attached is the rest of the table. I'll have to check the injectors and post them later.

 

They are a fast opening injector, seems to be too fast. At a nominal 14 volts the offset is 213 uSec. Maybe measure the resistance to make sure that they aren't a low impedance injector.

Be sure to multiply the values in the charts by 1000, as they are in mSec while the XDF entries are in uSec.

RBob.

 

Using a WB for ETOH concentration adjustments is a little different. Many years ago I wrote ECM code to do full time AFR adjustments from a WB set up. I found it very difficult to mash to go-pedal, mentally that is.

As I knew that if something went wrong I could lose the engine. I played with it a little bit but it made me so nervous I moved away from it. There have been several blown up Turbo Buick (TB) engines due to WB tracking (as they call it).

Just recently a TB owner was having issues where the engine would go very rich at WOT. Tracked it down to the WB controller being bad and reporting lean. He was lucky that it didn't fail reporting rich.

RBob.

 

So I redid the vacuum lines... the vacuum fpr is off the rear connection, and the MAP sensor is now off the front right manifold vacuum port... since the TBI/Carb adapter is an open style I'm not too concerned about it being on one side, since it should get vacuum from both banks. It definitely needs a retune though, since I also fixed the vacuum leak, it seems to be running rich... really rich. Next on the list is brakes and a transmission.

 

Doober, hope you get that thing sorted out!

 

Heh heh, thanks. I'm not extremely worried, it ran with that leak since I put the Vortecs on, and when it passed emissions the readings weren't as low as I thought they'd be, I'm hoping this will help. I've also fiddled with the timing, adding some advance here & there, so I'll probably run the stock table for the test, I've read too much timing can hinder emissions.

 

Nice. I have found that too much timing can indeed hinder emissions. I used to to take the spout connecter out of the fords to retard the timing for the dyno runs, the gms would have some other tricks also, like hoking up that timing plug to center it on zero. Some of those old cars needed all the help they could get.

As a side note, my 350 with the vortecs liked more timing that the "typical" timing stated for vortec heads. Give it what it wants. Maybe make an emissions bin for the annual test.

 

I'm still not too experienced with creating and analysing those logs, feel a little frustrated here..
How do you dump just a selected set of columns like in this .txt by bphage a couple pages back??? I always get the whole nine yards when I only need like 5 values.. Would be a great feature if you could mark, say, a certain time range and distinct columns that you want to export to csv/txt from the "Data Analysis" screen in the WUD.

 

For me, I dump the entire log, then run an AWK script on it.

If you don't know what that means, don't bother to learn.
Just dump it into a spreadsheet, and select your columns that way.

I do what I do because I'm typically looking at several hours worth of data, and I haven't yet found a spreadsheet that can handle that many lines.

 

Yes, if your interested in the thermal decomposition of the combustion process.
No, if you just want it to run !

In fact, "oxygenated" fuels do not add oxygen ! They are essentially pre-burnt, and therefore contain already consumed O2 in some inert filler.
The produce less emissions only because less of the fuel is able to burn. ( and, of course, produce some 18% worse mileage )
What alcohol does do, is mimic octane ( to an extent ) allowing the oil companies to sell you a MUCH lower grade of fuel than they used to have to produce, and yet charge you more money for it. ( and most importantly, Archer Daniels Midland gets paid )

Who cares ?

No, I'm not being sarcastic.
Who cares ? Usually, only we do !
The fuel doesn't care. All it cares is it either has enough O2, or not enough. Lambda.
The O2 doesn't care. Same reason.
The engine doesn't care. Same reason.
Even the ECM doesn't care ! It cares about Lambda, but it doesn't care what the AFR is or isn't. It cares that it needs to deliver X% more fuel for acceleration, not the AFR.
It cares that it needs to swing a % above and below Lambda to know what a narrow band is telling it, but not the AFR.
The cat-con doesn't care. It also cares about Lambda, but not the AFR.

Usually, only we humans care !
We do because we know that the cat-con wants a cycle above and below 14.7 stoich.
We do because we know that 12.x:1 gasoline produces more power than 14.7 stoich, BUT we don't NEED to care !
If we knew that x% more gasoline than stoich produces max power, then we can just as easily work % from Lambda as we can from our traditional AFR.
In fact, it would save a lot of thinking. We wouldn't need to adjust for E10, or E85, or even Nitro. Our same line of thinking, we need x% more, or x% less, would work universally, just as it does inside the engine and in the ECM.

The only time we might need to care, would be something like pursuit of max power for, say, E85. Is it the same % more fuel as it is for real gasoline in that engine ?
Personally, I don't know.

My EBL is set up for real gasoline. 14.67 stoich, even though the only thing available here is E10. It doesn't matter. I know that when the WB says it's some X AFR that it's really not, but since all I care is that I'm hitting the target number, or I'm not, it wouldn't matter if it said 14.7 or 100. ( actually, it might be easier if it did say 100. Then, even percentages require no thinking )

All I'm saying here, is that if you're going to delve into an esoteric detail that doesn't really matter, at least know that it is an esoteric mathematical detail that doesn't really matter as far as making the engine happy.

 

Hi all. I have another thread for this specific EBL application but I'd like to see if maybe my AE question will get more attention here. Quick primer: this is a GM 292 I6 (296 with bore). Offenhauser intake with 4bbl adapter and SBC TBI. VE is mostly tuned, though I have something curious happening at 1000rpm. It wants to go over 100% VE at 100kPa. Both the narrow band and WB indicate this. Aside from some intake magic making this engine very efficient here, what could be the cause? Anyway, here is my AE question. Even with the 7747, I was fighting this AE issue, though with EBL + WB I can finally see more of what's going on. It spikes lean then a bit rich, then a little lean (11.9-12 commanded in PE). Do I need async TPS AE? Or just more PW?

Each record is 1/17th second, btw. Here is the plot:



Obviously this causes a shudder. RPM and TPS uses the left vertical axis and WB on the right. I have another one like this at a lower RPM but I want to stay away from the funny 1000rpm area for now, in case the PE AFR is screwing with my AE evaluation down there. So this one is at around 2000rpm.

 

How does it behave if you roll on the loud pedal at a more sane rate ?

Smacking it that hard and fast, here's what happens....
Manifold pressure instantly goes high. The relative humidity in the manifold changes, and whatever fuel was there instantly condenses and rains out of the air, wetting the manifold walls. The engine ingests pure air, so the exhaust goes lean. In less than 1/5 second, the manifold stabilizes, the liquid fuel puddle in the manifold evaporates into the air stream, and the engine goes rich. The ECM is fighting for all it's worth to try and stabilize a catastrophically unstable condition. It wouldn't matter what your VE table was, even if it could go high enough, it simply can't react fast enough. Even if it could, the moving mass of air simply can't be corrected because it's already past the injectors.

 

Well stated. My feelings exactly. This may be more prone to TBI as compared to direct injection into combustion chamber!

 

I'll see if I can find a section where I smacked it less hard. Back with the original ASDV, it actually popped under this condition and I made good progress with the 7747. I think I can do better with EBL. I don't think these are totally unreasonable conditions. It would be going 60mph then planting the throttle to quickly speed up (manual trans) at 2000rpm. I'll get some shots at different RPMs at least. It seems better from higher RPMs.

 

According to the timings in your graph, you've gone from about 13% throttle to 100% throttle in ***less than one intake stroke*** !
That's asking a lot.

That one intake stroke, which will still lean miss, would have to suck in the entire volume of air in the manifold for the next cylinder to see something reasonable, and that cylinder would have to handle the rich condition it will see. The third intake *might* see a reasonable AFR, *if* your AE ( not PE. That hasn't had enough time ) is perfect.

You can "get away with" punching that fast at 5000, but not at 3000.
You can do it with TPI, again if your AE is perfect.

 

About 176ms from 13% to 100% TPS. I hit a peak of 45% dTPS, which is within the resolution of the TPS AE table.

I understand the conditions, I just think I can do better. Any suggestions how? This truck will eventually get a 700R4 and I can't help but think that it'll do this upon a good throttle stomp off the line. I don't think anyone would live with that. No matter how I mash the throttle in my Caprice, it doesn't stumble. So it's not JUST because it's a wet manifold, even though I know that makes it much harder to get right.

EDIT: Ok I found one slower stomp. Actually a bit slower than half a second. Same basic symptoms. The biggest dTPS here was only 20%.



The lean hump after AE is also an issue. But that could be the issue I spoke of before where both the NB and WB indicated lean down there at 100kPa.

EDIT 2: I added dTPS and dMAP. Maybe it will help. Surprisingly to me, dMAP happened first. Maybe I should look at MAP AE? I guess since it doesn't take much throttle to get a dMAP at low RPM, that's why it ramps up fast.

 

OK....

VE is a steady state thing. If the throttle is moving, VE sets the reference FROM steady state, so dinking with VE will only hurt you for a throttle "switch."
If you want VE at 2k RPM and WOT, you'll probably have to hold the brake HARD to give a learn enough time to see it as steady state.

After VE is right, then you can move on to your "stomp" and that will be entirely in deltas.
AE, and spark.
After that, you can move on to PE, and spark.

If you want performance, to paraphrase Grumpy, give the engine what IT wants, not what you think you want to give it.

 

Part of the issue is that the intake manifold is too cold. A stock TBI intake has a water jacket around the plenum and underneath the entire manifold. Adding some heat to the intake will help, I do the same on the carb intake I use on the TBI set up by running coolant through the exhaust crossover (no ports on the heads for exhaust).

Increasing the duration of AE will help with the slower throttle stomps. Lower filter values will lengthen it.

RBob.

 

Since we are finding ourselves in the pitiful (or not?) situation of having to define what to give the engine ... it would be good to think about it?

 

I would reduce both filters. Maybe 10% at a time. It may get better at each change. However if you get carried away it may hurt gas mileage.

when environmental temps drop issue will most likely get worse.

I once ran an XRam with 2 2.00 inch TB's and it was a worse case scenario for atomization and manifold wetting..