Restricted to 12lbs of boost and 750RWHP tells me they may know what they are talking about. Unrestricted, my car produced the highest horsepower they had ever seen on a stock longblock LS3 (only cam and intake change with headers). Just over 850RWHP.

 

I just read this one. I'm a bit confused. I know that my DC is too high. Anything past 80-85% they are not controllable... but, why would I add to the VE tables? Wouldn't that only make it run richer?

What if I just decrease the VE tables and boost fuel tables so that I can get my AFR closer to 11.4 or so... this would also help bring my DC lower wouldn't it?

 

Why would "anything past 80-85%" not be controllable?

The duty cycle is a measurement of how long the injectors are open vs the available window of time they CAN be open. They have no idea what the duty cycle is. They just open, or close.

Adding to the VE table will increase the pulsewidth.

-- Joe

 

To the TBI, the only thing I did was replace some of the TBI bolts with the bonnet hold down assembly.

This thing:

I really need to work on the tune... I heard others talk about low 12s for AFR but what makes you say 11.4 ? I wouldn't mind aiming for that... just wondering why so rich. I was thinking I might even aim for 13s if I added the meth injection system.

 

lol I'm the same way, I'm too lazy to fix it because as soon as the engine warms up it pretty much goes away completely. It only happens when the engine is cold. Although... could the opposite be the case?

I believe that it goes really rich, not lean... I'm almost sure that's the case from watching my AFR on initial throttle jabs. or maybe I havnt watched it while the engine is cold but I'm almost sure it still goes rich even then... basically no matter how small of a throttle jab... it almost always goes rich then after the AE decays the AFRs come back close to 13s and 14s

 

Maybe you cant see it in the back...

Look for this in the video:

 

Too much AE can cause a stumble as well, but usually I find I only notice it when I have too little AE. You will need quite a bit more AE when the engine is cold as apposed to warm. Before you start making any AE changes you really need a wideband and a datalog to see exactly what is happening when you stab the throttle (even little stabs). This stuff literally happens faster than you can watch any gauge or hear any engine stumble.

Also be advised that if you adjust your fuel pressure to get the injector DC in line, you will have to change AE. I believe Rbob posted a formula that you can use based on the pressure delta that will get it close to what it should be with the new pressure.

 

I've talked to others about this before which is why I was under that mindset.... below is what Cflick once told me about DC's.

I would think... since you can change the BPC constant in the computer and this changes the overall DC numbers, then this makes me think that the DC # is just a made up number? Which is why your explanation makes sense about the injectors having no idea what the DC # is that the computer is reporting lol .... maybe this is why RBobs BPC calculator is a nice tool? maybe it calculates the BPC values so that DC # you see reported is more of a accurate representation of the true physical limitations of the injectors you're using at the specified FP? Idk..

"Adding to the VE table will increase the pulsewidth."

Maybe I'm thinking about this all wrong. When you say it increases the pulsewidth... you mean, the OPEN pulsewidth correct? so more fuel?

I want to know if increasing VE table values adds fuel. I thought it did... which is why I was wondering why Ronny was advising to increase the VE tables since I thought I was already pretty rich.

 

I do have a WB... I'll run a data log and take a look once more. I'm pretty sure it gets really rich but I could be wrong. That makes sense because it got a lot worse when I vacuum referenced the FPR.

 

He's talking about the time it takes for an injector to open, and close, often called "injector latency". This should be part of your calibration and taken into account when calculating actual duty cycle.

On advanced EMS if you don't have the proper injector latency programmed in, you're fueling will be off and closed loop constantly chasing itself because it won't appropriately know how much fuel is going to be delivered during a commanded window.

I'm assuming you are running 17084304 injectors (80lb), which have a latency of .138 msec. Your total firing window at 6,000 RPM is 5msec on TBI.

I didn't notice your log entries in post #31, which clearly show you're injectors are static at various load/rpm points.

With that said, your AFR at this points is way richer than you should be from 4600 RPM onward.

The BPC calculator has no relationship to injector duty cycle. Pretty much every EMS has either a BPC or injector constant you enter, along with engine size, rpm range, etc to calculate required BPW.

I don't know how that thing tunes, if it's a 2/3bar VE table, or if it has a boost PW adder or what, but I'd be removing fuel up top however it's done.

Increasing numbers on the VE tables add fuel, yes because your telling the software that at that intersecting point the volumetric efficiency of the motor is higher and as such it requires more fuel.

-- Joe

 

Are you runnin open loop?



anesthes: How did you get latency tables?
When you say 80 lbs injector are you refering to early BB or later BB? I have 2560's in my car which I believe are later and were once thought to be 80's but I believe they were flow tested and found to be 75 lbs at 13 lbs FP.

 

Not necessarily. Remember the NB02 feedback should adjust fuel so result is stoich. However that is at CL and in those areas of VE table that car is runing in. Like 2000 rpms at 50 MAP you will get BLM and resulting correction to VE. WOT and 2 bar it may be nearly impossible to get CL feedback. you have have to adjust the VE table to give the car what you think it needs. Now if you are using WB feeedback in CL not NB it is possible to get WOT corrections. But that requires you modify accordingly. Now when injector is maxed on DC then all bets are off on any fueling control at WOT. Like the garden hose nozzle fell off and it is proving no control. rich could result. BPC should be accurate. Otherwise you have no sound base for tune. If you have an apppropriate fuel pump appropriate FPR and injector size it should show 80-85 DC% at heavy load. Then you can begin fine tuning

 

Wrote them down in my little book from when I was building a TBI setup a few years back. I believe I sourced the data from a guy on fullsizechevy that tested them. Edit: part # is above for the injector.

I thought when you guys run the EBL with the 'port mod' or injector mod or whatever it is, you can change your firing rate to twice per cycle to save on two dead times vs the standard 4 times per cycle ?

He's got a wideband, why is he running closed loop off a narrowband? Also, doesn't the EBL have a few different target AFR's now? Or is it 14.7 everywhere in VE unless AE or PE is triggered ?

-- Joe

 

I think it uses the RPM/VAC A/F table instead of the VE table in OL with WB corrections to PW to achieve that A/F in table. Kind of CL but in end has the corrections desired. Not sure how the mask looks for port fuel. EBL NB gives you PE A/F values based on RPM.

 

I run E10 so 14.1 A/F. If I left the calc stock L03 it would not matter as the end result is stoich with NB feedbacl CL. However I changed the scoich constant value in tune to 14.1 and moved the rich/lean/median switch points higher 7%

 

I meant like, do you have an AFR target table like this:



Or was it global.

I thought someone had recently told me that EBL had an AFR table, might have been Street Lethal, although I could be mistaken.

-- Joe

 

that being a two bar map table so I dont know. I dont have a boost table for ebl. But yes the OL table for 20-100 map looks same except the EBL has much more resolution.

I just thought of something. If I were to disable CL and run OL my VE table would need to be spot on to achieve the values in the rpm/vac A/F table. When using WB in EBL for feed back it must somehow change the VE table as I dont think BLM-INT is used. Possibkly it is locked 128. not sure on that.... Propietary?

 

Thats a single 12x12 2-bar table. I'm running a single 16x16. Whats EBL?

The example I gave is a 2bar single table. Some guys will run a 16x16 table from 0-100kpa, then another 16x16 table from 100-190kpa, and a third and so on up to 5. I don't really see the need for that much resolution between MAP targets.

Question for RBob. I've only used plain jane stock GM calibrations, and fully aftermarket. Wanted to play with an EBL but then I met MS.


I still stand by the tune being way stupid rich. The injectors are going static, but the AFR is way richer than you want at those RPM/MAP points.


-- Joe

 

E embedded B board L lockers

Not sure why is not ELB

dynamic efi

 

I meant, what size is the tables. You said it had more resolution. Are they 16x16 or much bigger?

-- Joe

 

The EBL Flash ECMs do it differently. The VE tables go from 20 to 100 KPa, and 400 to 8000 RPM. They are large and with good resolution.

For fueling during boost, the 100 KPa VE table data at the current RPM is used. Once the injector PW is calculated, there is a multiplier factored in. This "BST - RPM/MAP PW Multiplier %" table can have both positive and negative values.

The reason for negative values is that some compressors are not as efficient then others. So there is a need to reduce the fueling from the calculated value.

RBob.

 

Hello,

So in his case, you would be altering that table to remove fuel in the upper rpm where he is going static (and pig rich) rather than altering the VE table, correct?

So you've got MAP an RPM intersections, rather than just the MAP BPW adder like the old $58 code.

-- Joe

 

Thanks for all the help! ... I'm wondering the same thing. I'm thinking it would be possible to modify either/or ...

For example... I could decrease the boost PW tables to bring my AFR's higher, and not so rich at higher loads... If I need to remove a ton of fuel, I may even need to bring these down to negative values if necessary?

While I could also bring down the VE table values at 100kpa and this would also, in effect remove fuel since the boost PW multiplier values would multiply against a smaller value?

Same thing just different methods? or is there a preferred method?

Also, I'm starting to get curious about what Ronny was talking about. Is it possible to have the EBL in closed loop making corrections during PE at WOT? I didnt think it was.

Right now, I'm running fully open loop. It runs much better in OL and much more responsive. I hope this isnt a bad thing?

 

Removing fuel from the 100kpa VE column is going to affect all boost I'd think, since it's a BPW multiplier.

I honestly don't have the first clue about your other questions, as I don't know enough about the fueling logic on EBL. It's not stock GM code that I'd be familiar with.

I'm assuming you have a table with BPW adder based on map on the left, and rpm on the bottom (kind of like a second VE table) if I understand what RBob said.

On your VE table(s), how many rows and columns do you have? I'm curious the actual table size. (12x12, 16x16, 20x20, etc)


-- Joe

 

Take a look... the resolution varies I guess you could say.

 

Ahh that's cool. So it has a 17x14 main table, 15x14 second table, and a 5x14 "high rpm" table. A lot of aftermarket stuff will do multiple tables and allow for switching and blending as well, but normally it's because we want to run 1 BAR on one table, 2 BAR on the second, etc. I'm not, I've got my extra tables disabled and just edited my main table to be 0-190kpa. I should probably rescale my RPM since I won't ever see 7500. My tables are 16x16.

http://www.msextra.com/doc/ms3/tables.html

By doing it they way you are you have a lot of resolution to fine tune things all under 100kpa. That's pretty cool, must make n/a fine tuning a dream.

So what's the boost pulsewidth adder table look like? That's where we need to edit things.


-- Joe

 

I doubt that you will require negative values in the boost PW multiplier table. But if so then will need to do it.

Work on the boost PW multiplier table, from the log it is getting rich at about 5K RPM and 140 KPa.

Should use the boost PW multiplier table. The VE table is used from 0 through 15 psi of boost. So changing it will be a global change to the tune.

There is no real-time learning in the ECM when in PE mode. Can do VE Learns via the WUD in PE mode, but not while in boost.

No problems running OL all of the time. Isn't the best for mileage, but it works.

RBob.

 

It is a boost PW multiplier table. See the other screen grab that Napster posted right above your post. What is done is that once the fuel PW calculation is done. That PW is modified by the boost PW multiplier value.

Then the injector compensations are done and the ECM hardware programmed.

RBob.

 

I swear I only saw one attachment earlier.

That's a nice alternative to $58.

-- Joe

 

I may have missed this, but what kind of fuel pressure are you running under full boost? I am over 45 psi. Do you have a fuel pressure gauge going into your EBL? I am running a similar but different setup: Whipple with 9:1 compression, currently at 6 psi boost planning to put it at 8-9psi. What cam do you happen to be running, that will make the biggest difference on the boost you can run.

 

You spoke of possibly doing a water/meth injection on your setup. I have also been considering it especially if I increase boost.

With several great resources on this thread figured I would ask about IAT. Hopefully help us both.
Does anyone know if the IAT could be used as a fail safe? My current setup is air/fuel through: TBI, Whipple, Innercooler (A/W), IAT sensor right before entering the intake. My thought was I would put the water/meth injector after the innercooler so that the air charge would be lower hitting the IAT sensor. If the IAT sensor is responsive enough use the SA - IAT/CTS parameter in the EBL to increase timing. Then you could have the tune safe to use without W/M injection, but when in use it would increase output automatically; if pump went bad or tank went dry would have to worry about failure.

 

What is your timing set at?

I'm running 9.5:1 compression and 8lbs of boost and have not had any knock issues with MSD 6-BTM Boost Timing Master set at 1.5.

I do not see a bypass valve on your set up, it completely changed how my car drove. I sprung for a Mini Race Bypass Valve made by vortech 8D204-001 part number.

Love your set up!

 

To see how my timing compares to others - I am running about 31 under full boost. I attached my timing tables and a snapshot of a spreadsheet I put together to determine the actual. I fought a false knock for a while on my setup, but think that I got that taken care of.

Napster, curious to how your timing compares as well?

Cameron, do you know what your timing is under full boost?

 

Sorry for the delay,

I've been out busy fixing a cooling issue which scared the crap out of me but It's now resolved.

Here is a screen shot of my spark tables and boost retard tables.
The highest I've seen my 2bar readings so far is 8psi around 5500k RPMs.
Unfortunatly, I dont have a FP gauge going into my EBL Is it easy and cheap enough to do?

And yes, I'm still thinking about the water meth injection because I want to be extra safe.

I like you're idea regarding the IAT adjustments, it makes a lot of sence. It would really give some good incentive to keep you from running empty lol
I don't see any reason why it could not be used as a fail safe so that when the meth is off or empty it goes back to removing more spark to keep safe.
As far as my IAT location goes, I tapped a hole for it in the bonnet and bought one of the IATs that came off the turbo trans ams which had threads instead of the plastic mount.
My IAT is right next to the injector pod.

I still have knock counts but now that I fixed my cooling issue I'm going to put a few runs into the engine and see if my fixed cooling system prevents some of the knock I use to have before.

My compression is 9.8 based on the heads/pistion combo and my cam is a comp cam (model is below):

-Valvetrain:
Scorpion Performance 1.6.1 Self-Aligning Aluminum roller rockers
Procomp Electronics 190cc/64cc Aluminum Heads
ProComp Magnum 7.900" Push rods
ProComp Xtreme Energy XE268H Cam & Lifters (477" Int .480" Exh lift 268°/280)

-Intake/Fuel:
Vortech V2 Supercharger w/ Blow Off valve & 3.125" Pulley (6-Rib)
Aluminum Bonnet w/ TBI hold down
Walbro 255lb Fuel Pump
Aeromotive 13301 Fuel Pressure Regulator at 25psi Vacuum referenced
454 7.4L BBC TBI w/ 80lb Injectors (Pressure cleaned and flow tested at 80lbs)
TBI to Carb 1/2" Intake Adapter Square Bore 54mm
Edelbrock Performer RPM 7101 Aluminum Intake w/ divider cut down 3/4"

 

Well, I believe my timing runs around 28-31ish at WOT. I know I have some date log pictures earlier within this thread.. or if not it might be within the EBL tuning thread on one of these pages; 49, 53, or 55 ... pretty sure 55 has some:

https://www.thirdgen.org/forums/diy-...ng-ebl-55.html

Just do Ctrl + F then search Napster

I'm too tired to go through my other computer for a data log at the moment lol

And thank you!!

 

For fuel pressure, it is fairly simple I spliced mine in after the fuel filter which worked great on my truck. I used Auto Meter 2246 and Rob already has it setup with correct parameters in EBL. I would say around $125 -$150 with the connector.

After doing some research it looks like the IAT senor will not react fast enough to provide a failsafe. This is probably why none of the Meth injection companies utilize this solution. Hopefully someone can prove me wrong or I can find a faster acting thermocoupler to build a custom IAT sensor.

Just speaking from experience I would not push your motor or go any farther tell you get the knock figured out. My first engine was 9.5:1, with vortec heads, Comp Cams 08-503-8 cam giving me over 12:1 dynamic compression. I did not have a catastrophic failure, but I did end up messing up rings on cylinder 7 and when I pulled the engine apart on a 10k mile stock rebuild the bearings were almost all down to the brass lining, but still not rod knocking. When I built my second engine and had it on the dyno we were getting false knock (determined after many tests) and luckily the shop wouldn't let me go above 10 deg advance tell we had the problem solved. I am not saying this to be an *** I just do not wish the troubles and expense that I went through on my build on anyone. I would definitely be checking your spark plugs for detonation if you have not already done so.

That is kind of crazy that you are staying rich; whenever I have had my DC go above 100% for any amount of time at WOT I went scary lean.