Hey all. As the title states, I have Wavy ve tables. I've had the EBL since it was first released. I've been tuning on and off now since then. Whenever I have a hour or two to burn driving around, or to work, I'll do some tuning. To get to the point, my VE tables are wavy. IOW, at low maps, 20 to 35 KPA, its low, then 40 to 55/60, the VE rises, then it drops up to 85/90 kpa, then it is high again, for the WOT. It is more prominent since I started using the new VE learn feature for the EBL, 1.8. BTW, I have a VAFPR, would this have something to do with it?? I'm a little lost here on what to do.

Should I try and fix it? Or leave it be?? Seems to run much better after a few days of the new VE learn, saved me TONS of time hand smoothing this thing.

Thanx for any input guys.

O, how can I post a picture of my VE tables to show you guys??

 

ALT Key and Print Screen

Then open the photo program of your choice and paste it as a new picture.

It is normal for the VE to be a little wavy, it should however for the most part always have an upward trend. The higher the MAP the more fuel you need. It is not un-common to see RPM related dips though.
O, how can I post a picture of my VE tables to show you guys??

 

ALt print screen don't seem to work for me, nothing happens. I'll have to figure something out here.

 

After you hit ALT PRnt screen, you have to paste it into a photo shop program. Just hitting ALT PRNT Screen won't do anything noticeable by itself

 

Sounds like the mix of injector PW offset vs VBATT, and the VAFRP. Hard to say for sure though. The low VE for low MAP would be an indication of too large of an injector PW offset. The other stuff could be a mix of Injector flow rate vs Vacuum or whatever EBL uses, and the actual fuel pressure. The throttle angle at the very high MAPs could also have a small effect of maybe 2-4%.

 

Also just because you used the math formula for calculating the injector flow at various pressures does not assure that the injectors are flowing exactly that. I've noticed this with the MAF setup which uses true measurments rather than approximations. The higher the pressure gets from the initial setting, the higher the error seems to get. I found at 32-36 PSI with TBI injectors, they actually overfueled by about 10-15% compared to what the calculations said.

 

I'm thinking somewhere along the lines of that, the math for the calculated fuel pressure. It's hard to tell exactly what the BPC vs VAC table is supposed to be though. I can't really drive and look at the same time. At a FP gauge that is. lol. I'll post some pics of the VE tables When I get it to work. POS puter

 

liquid,

Are you using a VAFPR? I use one on my setup witth pressure varying between 11.5psi up to 20psi at WOT. I have a "wavy" Ve table particularly in the Lo VE/ Lo RPM cells. The 1200rpm/35kPa to 1500rpm/45kPa cells are higher than the subsequent cells. then everythng smooths out relatively speaking. Could be manifold harmonics, certainly the cam is a bit lumpy in that range, and maybe my BPC v VAC numbers need to be massaged a bit.
Nothing guarantees that the spring in the VAFPR is linear. At the lower kPa, the spring is compressing and pressure will vary simply based on the spring warming up from cold.

 

Yes I am, but my pressures range from 15 to 28 psi, My VE is high in somewhat the same areas, 35 to 55, 1000 rpm to 1800 rpm, the a dip in the same map, but 1900 rpm to 24 rpm. The in the same map it climbs back up. I may fudge the BPC vs VAC table and drive around and try it out. I have to find the chart that tells me what the MAP KPA is for the corresponding VAC KPA. I forget how to do it. I want to keep the VAFPR simply because it runs better with it that having 28 PSI FP all the time.

 

liquid,

Here's the .xls RBob gave me to do the BPC calc. If you have modified the BPC down low, let me know how you make out. I'm assuming you would increase the BPC in the 35-45kPa range. I may want to bump mine by 1 from 45kPa on down so as not the reek too much havoc on my cruise rpm/kPa cells.


Edit: For some reason the zip file won't work when uploaded. It works fine on my laptop. Let me send it to you.

 

Thanks Dominic, I'll try it out. I'll increase it in the areas where my VE table rises, and see what happens. I know I was fudging the 95-100 KPA areas as to keep me from going to 100%.
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Says that it is not a valid winzip archive. Maybe try posting it again??

 

How does it run?.
Wavy is a human term, the engine just knows what makes it happy or not.
If it runs correcty, that's what matters.

 

Bruce,

You're right. It does lean out especially in the sub 1400rpm range which is why the VE shoots up. There are some spots in the VE table in 1200-1300rpm that call for 50% VE. Maybe trying to make it look pretty just has to do with that whole Greek philosophy thing about symmetry.

 

I second that notion. haha. I have a bad habit or trying to keep thing linear and symetrical! This habit has proven to be a hindrence in my tuning sometimes. doh!

 

Ok here, I figured it out. Here they go.

 

The dip in the high VE tables in the middle (2000rpm to 2400 rpm) is what is screwing me up as far as tuning. That is my cruise area. And the BLM's won't hold steady there. The are quite a few numbers lower than the surrounding areas. 68 verses 72 for example. If I can get it to stabilize, then I wouldn't have a complaint.

 

Mine looks quite a bit rougher than that. I have a big bump in the 1000-1600rpm range for the lower kPa cells. It s a little choppy in some other spots particularly and then it smoths out att around 2000rpm which is when the cam starts to come on. In fact my DGD MPG display will show that I get better gas mileage at 2500rpm in 5th than I get at 1800rpm in 6th. Motor sounds happier too.

 

Got tables?.
Some of us don't have the eyes of the younguns. <G>

 

lol, you just have to zoom in on it and yuo can see it.

 

liquid,

How are your trials on playing with BPC in the BPC v VAC table? I have been modifying mine increasing the BPC by 1 each time for the higher VAC values which correspond to low kPA 20-40. That seems to be helping as far as smoothing the VE in low rpm/low kPa region.

 

Dominic, I uploaded a new BPC vs VAC table 2 days ago, using the spreadsheet I got from you. I went out and double checked the FP, I have a peak of 24, not 26 . So, I came up with a new set of values and loaded them in. Then I dropped both High and LOW VE tables by 8 (13 highlighted table clicks down or so ). I drove to and from work for the past 2 days and all around. Needless to say, the VE wasn't far off when I did that, then the learn was great. I am within +/- 1 in all the driving areas. It's never been like that. I'll upload the new tables in a few minutes. My 100 KPA isn't at 98 no more, it's at 90 or so in the upper rpm's.

So my tables are a bit smoother now. Seems to run a little better. My AE wasn't thrown too far off either.

How about you??

 

Here they are. Still not "flat", but not as bumpy.

Low VE, click and expand.



High VE, click and expand

 

Liquid,

I have been playing with the BPC at the lower end of the scale. Anything from 45kPa VAC to 80. That's where my "lump" is in the lower rpm ranges. I bumped the BPC by 1 from 55 thru 80 just trying to take it slow. The motor really seemed to like that. The lump is still there after a Learn but it seems to be getting smoother. Now RBob's sent his latest WUD 1.9 so I am hoping to try out the smoothing algorithm. I think I will still bump the BPC but now only from the 60kPa VAC to about 70kPa. I don't want anymore fuel in the decel area of the VE table. The Learn VE is showing changes of 1-3% over the the majority of the table. It felt very good driving. And now when I hold third gear jut before going into PE, my BLMs are right in the 128 range. So I think I'm on the right track.

 

Bob, there is a 1.9 already?? Yu gave me the 1.8 3 weeks ago, and there is an update already? ooo, ooooo, Can I have it?

 

I'm glad it is working for you too, hat is what I have been doing. Just weaking the BPC's in the wavy areas, and getting good results like you. I too have noticed it running better, and the BLM's are getting more stable.

 

I think Dominic is creating his own versions of the WUD

The latest is 1.8b, Help -> About will show the version.

RBob.

 

Attached are 3 pic's of VE tables, all from the same vehicle: an '85 LG4 Camaro (converted to TBI).

The first pic (VE1) is what I started with. Doing data logs of about 26 miles each. First three VE Learns was with a smoothing factor of 12, then did two more VE Learns with a factor of 9. The result is shown in the second pic (VE2). The little peak at 400 RPM, 100KPa is for a tad more crank fuel.

The engine is so much smoother running it is night & day difference. And the BLMs are flat across the board.

A little on TunerPro: you can rotate the graphs by holding down the Ctrl key and mouse click & hold on a corner. Then move the mouse to spin the graph.

Dependent upon the range of values in the graphed table, the graph can exaggerate. Note the last pic (VE3), other then expanding the range it is the same table as shown in the second pic. But with the full range of 0 - 100% shown, the graph has a different look.

RBob.

 

Here is a spread sheet that calculates the BPC vs. injector flow and engine displacement. It is set up to provide the values for a vacuum referenced fuel pressure regulator. It may also be used to calculate the BPC for a standard FPR. Just use the value at 0 KPa for all entries.

RBob.

 

Sorry Bob. I was going off the XDF version you had. BTW, I like where the VE table when Correction is selected only shows a % only after a partticular cell is being re-calc'd. Otherwise, there is just a dot in that MAP v RPM cell. This way you can see which cells had no hits. I'd like to suggest that in addition to the 3 options for the Learn VE being Orig/New/Correction, have the number of hits displayed for each cell that was re-calc'd.

 

This is a test

 

No go Dominic, you and Bob's upload is corrupt or something.

 

Thanks. So its not just me.

 

Dominic and I corresponded a few times and came up with this. RBob said the calculations looked correct.

http://www.foxmustang.net/mic/bpcforvafprcalc_mod.xls

I put in quite a few absolute cell references. That way you can change the key-on FP and watch the BPC's change. This was useful to me because I knew how much injector I needed but those calcs were done at WOT where I'm at ~5 psi of boost. This lets you change all the setting until you arrive at a combo that works.

 

RBob,

A word about the smoothing effect. Having used the TPro smoothing feature I was able to highlight the portion of the VE or SA table I wanted to smooth. This allowed me to retain the portion of the VE table that I had locked in for WOT operation. The EBL smoothing smoothes the entire table including the area I wanted to kee "as is". Anything you can do to allow the same type of smooth highlighting in EBL?

 

Dominic, I have been doing the same thing, just blend in the new with the old after I copy the EBL smothed portion.

Lately I have been having an issue with my BLM counts, the past few days they were on, either 0, or =/- 1, today They were high 3 to 5, what gives? I wonder if the abient air temp is affecting it? Other than the temp out side nothing seems to have changed.

I also have to look more in depth into the prop gain stuff, I don't know exactly what it does I'm sure I can gain something by learning what it does and if I need to change the settings.

 

If I used that table, it drops all my current, and previous BPC setting by more than 10. When I had my 0 VAC/100KPA to 72 before, my VE tables were 99% at the top end, 5600 rpm, using this table, it says to set it at 68, I would run out of VE table to fuel this bucket. Right now I have it at 77. (0VAC cell), I guess I could use this table as a reference, IOW, play with the idle FP till I get the BPC I need in the 0 VAC area, then it will scale down the rest of table for me.

 

It won't be right on because injector flow is not perfectly linear. If you have a combo that works, go with it. It's useful to me because I have no idea what my engine is going to want the first time I start it. I just converted from a QJet to this so there's no better starting point for me.

 

liquid,

That's why RBob fudged the numbers on mine so it would start out with the BPC I was using without the vacuum port operative. So the BPC table have been using was based off of a 390CID motor which gave me a BPC of 96 at 0 VAC and 20psi FP. I played with the BPC originally for the same reason you did.
As for the Prop Gains, I would refer to RBob's paper on that. It can be a bit like Chinese food. As you read it, you think you understand it, but then you're hungry all over again.
RBob, please chime in on this. Don't want to lead anyone astray. But recently I was able to finally get it when RBob explained that if the exhaust sounds like you have a bad U Joint, then that's a sign of too much Prop Gain. If the INT is having to move up and down more than +/- 4 to maintain the BLM, then its not enough. It seems to me that the Prop Gain is there to take up the slack until the INT and BLMs can be optimized by the ECM. I think of it as a "pumpshot" and the tables give you the ability to modify both the duration and amount based on airflow and O2 sensor readings. It helps narrow the variation in the fueling because of the ECM calc lag.
The way I tuned the Prop Gain was to slowly increase RPM in each gear. Where I felt a hesitation or bucking of the motor, I'd mark that in EBL scan, then drop the Prop Gain at that airflow. Now the motor accelerates smoothly in any gear and I can also hold it at a higher rpm without getting a seesawing effect. Make sense?

 

That part does, So I would just play with the gain? I've been rading RBOB's paper, but I have to reread a few times so it all absorbs in so I can understand all the dynamics. As far as the INT moving more than =/-4, it does sometimes. I may log a short drive for lunch and took a look back at it. Can I tell by anything else in the log that the Prop gain is off? or is it a real time feel kinda thing? I searched a few other post from previous people, but the info was more on other ECM's. The EBL has way more tables to adjust and mess up, haha.
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That is what I have been doing, same as Dominic, just finding what the car likes. Which is a PITA sometimes, but...... It gets faster the closer I get the tune.

 

"Can I tell by anything else in the log that the Prop gain is off? or is it a real time feel kinda thing? "

Looking at the logs, too much gain will show up as rapid changes in the O2 sensor voltages. That translates to the "bucking" or the U Joint noise I was talking about.

 

ok, I'll have to go back over the last 2 logs or so from the current bin. I never got to take it out at lunch. But I'll log it on the way home too. 1 hour drive so I'll have plenty to look at.

Also, general question for anyone. What should I adjust for the ambient air temp changes Is it the IAT vs CTS?? All that references to is a gms/sec. Other than that, there is no ctv vs bpc or something to make it leaner as the air is colder, and richer as the air is hotter.

Or...., am I SOL because I have the GMPP highrise (think Edelbrock RPM), open elements and cowl air?

It is getting to the point I want to mess with the little things now. Thanx guys for all your replies and help!

 

"Also, general question for anyone. What should I adjust for the ambient air temp changes Is it the IAT vs CTS?? All that references to is a gms/sec. Other than that, there is no ctv vs bpc or something to make it leaner as the air is colder, and richer as the air is hotter."


Where is your IAT sensor located?

 

It is ziptied to the air filter right now. I have a 4 inch cowl induction hood, and the air cleaner sits right in the scoop, so I have the IAT right there.

 

One thing that helps is to use the lowest smoothing factor possible for the desired results. Once the VE table is close then a factor of 6 or even 4 can be used.

I've played with having the smoothing only affect the area that was learned in. But if done too early in the VE Learning cycles it can leave steps in the table. Which is the opposite of what is desired.

RBob.

 

If the change in the BLM is the same across the VE table I wouldn't worry about it. All it takes is a change in fuel, humidity, temperature, and a hand full of other items to cause the BLMs to change.

Proportional gains: the purpose is to force the AFR to oscillate. This is seen in the O2 reading as it rises and falls in a rhythmic pattern. The prop gains do this by increasing and decreasing the injector PW. So, if the gains are too high, then the PW and the resulting AFR swings too much.

RBob.

 

Fast,

Interesting point. I did the same as you, and connected a vacuum gauge to a Mity Vac pump with a T to my Aeromotive VAFPR. The FP gauge is on the regulator. I warmed motor up first to get thing to operating temps.
Here's what I found for observed vs calc'd numbers



As you can see when we get into low MAP area, the FP is getting on the ragged edge for TBI < 9psi. May explain why LOW RPM/LOW MAP needs the bump in VE that it does. I'm going to adjust the BPC table using the observed numbers and see what happens. As RBob has said, there's been a suspicion of the VAFPR spring not being linear.

 

I should do that too, just have to get a new vaccum pump.

 

It was a nice sunny day so took the car for a spin with the new Observed FP numbers used to determine BPC for the VAFPR. It actually ran pretty nice at cruise but the funky area of the VE curve got exaggerated further because I dropped the BPC in the lower MAP areas. As Grumpy says, give the motor what it wants. Not sure I'm gonna fight this anymore. I think its the cam. Once I get to 2000rpm, it really starts to purr. I get better gas mileage at 2700rpm than I do at 1800. Here's what the lower VE looks like.

 

Your table is a bit more wavy than mine. I actually have left my current VE tables alone for the past few days, seems to run real good, BLM's are somewhat steady too. I re-enabled lean cruise and I am getting 16 MPG, so for this POS that is good, compared to a few weeks ago. Still using the winter gas too. I havet urned to tuning the AE a little more, as you know, change the VE and the AE changes too. I am pretty darn close though. A few quirks here and there. When I buy a new USB cable I'll post up my last track run, and the EBL 1/4 mile run.

 

I figured out part of the issue I was having with "wavy VE files". Turns out I may have had a small exhaust leak. Not sure if it was at the collector or at the muffler/tailpipe junction. But I happened to need to adjust my mufflers the other day due to a broken muffler hanger. Re-did both sides. In the next datalog, VE Learn was now taking out fuel in the low rpm/lo MAP sector where before it was constantly adding it in. So hopefully a few more datalogs will help to bring things back into line.