Timing Bias?

[2006Cummins]

I was reading somewhere that the timing numbers that are displayed in the tune files are actually not correct. I think I remember something like up to 20* high? Can anyone straighten this out for me? Thank you.

[AdamRRT]

Yeah I'd like to know ahead of time what tables those are. Thanks.

[GMPX]

There is a bit of an unknown at the moment with regards to timing values. There is a calibration in the ECM that appears to put a -20 degrees bias on the final timing figures.
But at this stage I haven't been able to figure out if that timing bias is always applied to the final figure the engine sees or if it's just what is reported by the scantool data. There was going to be an experiment done on a truck with a scope but it's never happened.

[AdamRRT]

Yeah that's not uncommon as I'm sure you know. Many vehicle tables do this, so that they're always dealing with positive integers. I just would like to know what tables have it and what ones don't. It'd be nice to have a list rather than have to determine it each time I open a table.

Thanks for the assistance. I'm loving this!

[GMPX]

It's not quite the same as what you are suggesting (or I misread your post). The Cummins timing values are all signed numbers so it can go positive or negative anyway, the bias is almost like the system has a known delay of 20degrees before the fuel actually begins the injection so therefore they put that in so the numbers we see in the scantool or maps reflect the reality of what happens at the engine (this is just a wild guess).
So to answer what tables does it affect, the answer is all of them because it's more like Final Timing = Timing from all maps - Bias.

[AdamRRT]

Oh I misunderstood then. You understood me well, despite me being mistaken. Thanks for the response. So if we say I'm putting in a value of 5* BTDC, is that really going to be 25* BTDC in the engine?

I just can't imagine like say on the values that have us using a timing of -50*... so we're really beginning injection event at 70* BTDC? HOLY MOLY!

Or am I going the wrong way with it? Just seems like we'd be getting some serious timing rattle. Plus there's a point at which we're spraying outside the bowl if I am correct in my ideas as to why most burned pistons seem to occur (especially Smarty + TNT).

[GMPX]

Oh I misunderstood then. You understood me well, despite me being mistaken. Thanks for the response. So if we say I'm putting in a value of 5* BTDC, is that really going to be 25* BTDC in the engine?
Yes.

As an interesting comparison, if you look at the tables below. Both stock, one being an LMM the other a Cummins, however the Cummins has had 20 degrees removed from the table ('the' bias), interestingly that puts the part throttle timing values in a similar range as the Duramax runs. Unfortunately the X,Y axis's between Cummins and Duramax are opposite so a direct overlay is hard.

http://download.efilive.com/Software/Images/LMM_Timing.png

http://download.efilive.com/Software/Images/Timing_Bias.png

[AdamRRT]

Ok, so just to be SURE I get it, the -3 in the upper left corner of the Cummins table...

That is 3* BTDC?
That will give an actual timing of 23* BTDC? (provided the -20 is correct)

I know this is basic, but I've looked at so many tables for the past 48hrs that it's starting to all run together. And I want to be SURE I'm speaking the proper language before I go any further. As I've said, I've used HPT a bit, but every software is just a little different. As is the fact that it was gasoline stuff.

Thanks, Ross!
- Adam

[2007 5.9]

No..-3 is actually 3*ATDC.
0* is 0BTDC..20 is 20*BTDC.

The (-) values indicate timing ATDC

Kinda confusing at first.

~Les

[AdamRRT]

Yeah, only because it's backward. But not. LOL.
So the -3 value means it is asking to begin the event at 17* BTDC?
Sorry just wanna be sure I'm getting this 20* bias thing properly. Basically, I'm asking do we tell it 20* more than we want? Or it RESULTS in 20* more than what we ask for?

[GMPX]

Adam, the 20deg bias isn't 100% confirmed in operation. We know it's there but not sure at what point it's applied. This was why the idea of scoping the injectors and crank trigger was thrown around.

[AH64ID]

Yeah, only because it's backward. But not. LOL.
So the -3 value means it is asking to begin the event at 17* BTDC?
Sorry just wanna be sure I'm getting this 20* bias thing properly. Basically, I'm asking do we tell it 20* more than we want? Or it RESULTS in 20* more than what we ask for?

If you add 20° to those numbers that where the bias comes into play. You can see on this table there is exactly 20° more advancement on the number.

If the 20° is true across the board it shows how retarded the timing was made for emissions reasons.

http://i79.photobucket.com/albums/j156/ah64id/Yotatech%20Stuff/timing.jpg

[AdamRRT]

I'll call my tuner buddy and see how soon I can put my truck on his dyno to see what's up with the bias.

[comnrailpwr]

The dyno won't tell u any information about the timing bias.

Jake

[AdamRRT]

Sure it will. We can easily tell if theres 20* from intended by going for timing rattle or by even seeing if we lose power where we should or if it takes another 20* to do it.

[comnrailpwr]

I dont know if u understand this bias or I'm not understanding what your trying to accomplish with the dyno. Sure it'll tell u what # in the software gives u max power and @ what rpm its happening but thats different on every truck and not relative to the bias at all.Basically I command 50* max timing with the software. In all actuality I m only getting around 30* because we know the truck cant live at 50* actual. When and why the bias is there the dont know, that's why we need someone with the proper equipment to scope the injector. I think I'm on the right track at least lol. Anyways keep up the good work, it gets better everyday.

Jake

[AdamRRT]

I understand it just fine. After having it explained a bit on the phone. We know that it should rattle at X rpm & Y timing. If I tell it 50* and get it acting like 30*, it's there. What's hard about that?

[06dodgecr]

What's the rattle you speak of because I can get it to rattle with rp?? Your idea won't work but if you'd like to guinea pig a motor please tell us where it rattles to the point that it stops rattling and begins banging..lol

[comnrailpwr]

I understand it just fine. After having it explained a bit on the phone. We know that it should rattle at X rpm & Y timing. If I tell it 50* and get it acting like 30*, it's there. What's hard about that?

We know its there. We want to know why, when, and how do we fix it. And there is no x rpm or y timing these trucks rattle. It will varry for every truck. it is there when we dont have any rattle. Plus whats acting like 30, we have never been able to adjust a CR before by the timing degree. Its always been pre determined by box tuner manufactures who themselves were clueless about this. So we are clueless what 30 actual degrees "feels like"??.!?

Jake

[easymon]

Sure glad this is being brought up so it can be fixed so we all know in stead of gess. Puting a $12,000 motor as a ginni pig is rediculass .

[AdamRRT]

Seriously, are you just trying to argue or do you have anything to offer? Yes it varies but not by 20*. You should easily be able to hear timing rattle and know when it shouldn't be happening based upon diesel engine theory. 20* is a huge difference.

And according to the thread, apparently we don't KNOW that the bias is there. It's thought to exist. That's what's been said repeatedly.

[AdamRRT]

So you think I'm going to do it to the point of damaging the engine? Why would anybody do that? You can get timing rattle without destroying an engine. If you don't know that, get away from EFILive. You just don't leave it as the norm.

[DoghouseDiesel]

Sure it will. We can easily tell if theres 20* from intended by going for timing rattle or by even seeing if we lose power where we should or if it takes another 20* to do it.

Won't tell you squat on the dyno.

I guarantee I could set this at and indicated 50*, 30* or 17* and you wouldn't know the difference in the sound on the dyno until it was advanced enough to go BANG!

Let's cut through the BS.

Until someone is willing to pull out an o-scope and hook it to the injectors and get a reading, we won't know where it actually takes place.

What we do know right now is that in the tables, if you command, for example 30*, what you'll really get is 10*.

This value is being introduced by the ECM, but it's not confirmed yet. Until it's confirm, they don't want to make any changes to the software that could be potentially disasterous.

Sometimes, the best thing people can do is step back and listen and not act like they have all the answers......just sayin.

[AdamRRT]

I in no way think I know everything. But I know that adding timing causes the sound to change. That there should be a huge difference in sound and smoke comparing 5* to 25*. Is that debatable?

Ok and it's said even by Ross that he's not sure that the bias is there. So we can walk the timing up and see if the bias is there. Not why. Why doesn't matter, as long as we know there IS some bias. That's all I'm saying.

I can't be acting like I know it all in the thread I'm clearly admitting to needing help. That doesnt even make sense. Come on be realistic. That's all I'm saying. No need to jump onto me. If I'm misunderstanding, clarify.

If you KNOW it's there when Ross says THINK it's there, SPEAK UP and correct him. We are adults here. Let's help each other. Share your reasoning cause I'm left thinking that it's somehow unable to be heard which is just strange since I can load CL right now and hear tons of timing rattle.

[AdamRRT]

Sorry if I came across the wrong way. Not sure how I could when I clearly asked for help. And when guys are admitting to hearing timing rattle when they increase pressure, but others can't hear it?

Let's figure this out is what I'm saying. Work together.

[FUBAR]

I can't believe Lee hasn't jumped on this...anyhow. I think we can all agree that the issue at hand needs fixed. I'm starting to think the bias is only elected under certain conditions. What conditions? I don't know. Maybe when certain injection events are or not occurring. But from some evidence from what I'm seeing, it may not be all the time.

There are many well respected engine, tuning people and all-around motorheads on here that it's hard to believe somebody can't or doesn't know somebody that is capable of scoping an injector.

[AH64ID]

What we do know right now is that in the tables, if you command, for example 30*, what you'll really get is 10*.

Is this happening at all rpms and fuel flow?

[DoghouseDiesel]

I in no way think I know everything. But I know that adding timing causes the sound to change. That there should be a huge difference in sound and smoke comparing 5* to 25*. Is that debatable?

Ok and it's said even by Ross that he's not sure that the bias is there. So we can walk the timing up and see if the bias is there. Not why. Why doesn't matter, as long as we know there IS some bias. That's all I'm saying.

I can't be acting like I know it all in the thread I'm clearly admitting to needing help. That doesnt even make sense. Come on be realistic. That's all I'm saying. No need to jump onto me. If I'm misunderstanding, clarify.

If you KNOW it's there when Ross says THINK it's there, SPEAK UP and correct him. We are adults here. Let's help each other. Share your reasoning cause I'm left thinking that it's somehow unable to be heard which is just strange since I can load CL right now and hear tons of timing rattle.

Alright, I'm not gonna sit here and argue with you about this.

This is as realistic as you're gonna get it.

I GUARANTEE, I can put my truck on the rollers RIGHT NOW and set the timing to whatever I want and YOU will not know the difference except in power produced.

Rattle can come from several different causes, not just timing. Rail pressure has a lot more to do with injector rattle than timing does.

What you want is a guess. The EFILive team has made if very clear in earlier posts that guesses will not yield changes, data will.

SO, if you want it change, here is what YOU need to do.

Get an o-scope, hook it up to the #1 injector and lets see what the actual timing is vs what the ECM is reporting.

Do we have a good idea it's there? YES!

Do most of us tune around it? YES!

Is the data there to DEFINITELY support it? No.

Do we know that it is ALWAYS there or not? No.

I don't have an o-scope. Do you?

[AdamRRT]

Yup. Very little I disagree with there. Close enough. But let's be adult men and know that it's a DISCUSSION on a discussion board. Not an argument.

Out of curiosity: Where did ANYBODY ask for changes in this thread as it relates to this timing bias? I'm not sure why that keeps getting mentioned.

It's easy. Just say it's on these tables. Tune around it. If you're so sure it's there. It would have saved lots of discussion.

So thanks for getting close to it man. It makes things much easier. Sorry for the confusion.

[THEFERMANATOR]

To find the bias you will need somebody with a scope to go in and scope teh crank sensor VS the injectors at the same time, and then cross reference this to the timing table. Another option may be to put a TDC mark o nthe balancer and go old school with a timing light of sorts that fires off the injector pulse. Jusat listening for rattle will do absolutely nothing as no 2 trucks will rattle at the same point. Hence why one treuck can run 30 degrees of advance and be fine meanwhile an identical truck can run the same tune and lose the rods and pistons with it. The only way to absolutely know ill be to get it on a scope and graph the bias while datalogging with the V2 to a PC or something to overlay teh graphs. And judging from that timing table of teh CUMMINS, I highly doubt there is a 20 degree bias throughout the entire range as 7-9 degrees ATDC would run pretty high EGT's in those power areas I would think.

[FUBAR]

There's got to be somebody out there that's capable of scoping an injector...

[AdamRRT]

I never heard back from Bluecat, FUBAR. I'll call him tomorrow.

[Ira]

Tomorrow I'll be sending my Fluke 98 or another one of my scopes to DogHouse diesel so they can finally try to answer the timing question.

Ira

[GMPX]

I have a scope.......but no truck :grin:
Thanks Ira, hopefully this will finally shed some light on what is happening.

[FUBAR]

Yes, thank you very much!

[comnrailpwr]

Thanks IRA, Much appreciated. Adam you have your opinion and I have mine, nuff said.

Jake

[DoghouseDiesel]

Thanks Ira!

As soon as we get it here, I'll have Eric rig it between the crank sensor and #1 and I'll clear some dyno time and see what's really going on.

You Rock!

[AdamRRT]

Thanks guys. Sorry for the misunderstanding. Yes we have our own opinions I'd hope. But in the end we are working toward the same goals here. Apparently I misunderstood when it was said "think it exists". I should have read it as "know it's there but unsure to what degree". Which would've cut short my crap. Sorry about that, to the degree that I played my part.

[FUBAR]

Thanks Ira!

As soon as we get it here, I'll have Eric rig it between the crank sensor and #1 and I'll clear some dyno time and see what's really going on.

You Rock!

You both rock!!! :rockwoot:

[olboyowl]

awsome. thanks fellas

[2006Cummins]

I'm really excited to see the results of the scope!

FYI, I just data logged my bully dog programmer, and on tow, performance, and crazy larry, it commands a maximum of 45* timing.

Mike

[DoghouseDiesel]

That's because of the ECM's limiter.

I guarantee if you look at the tables, it's asking for higher.

The ECM's limiter is set at 45*. You can ask for 60*, but unless you raise that limiter, 45 is all you get.

[FUBAR]

Rich is right. This is the case I've seen for all programmers. Makes you wonder what they're actually doing when they tune. Modify a few cells (probably WOT etc points of the table) and blend everything as a fast, slam, bam, thank you mam way of tuning....Who knows.

[DoghouseDiesel]

Well, I talked with both Ira and Eric today and I feel like a moron as we may have had a solution sitting here all along.

On the dyno, we have all the Innovate data loggers that are used for the gas motors. Stuff like boost sensors, induction sensors, AFR sensors, etc....stuff that we just don't use on the diesels.

Well, after talking to Ira about the Fluke and Eric about the optical pickup and the induction sensor, we may actually be able to see the actual timing........IF the induction sensor can see the signal to the injector AND if we can get the reflector on the crank damper at exactly 180* opposite from TDC.

If the Innovate software can talk with the dynojet software, we might be in business.

Eric is going to talk to them tomorrow and see if the sensors will be able to pick up the signals and if the software will talk correctly.

[comnrailpwr]

Sometimes solutions are right there under your nose. Sucks when u scratch your head for weeks and lose sleep. Think of all the beer money we could save if we had solutions pop up like a light bulb on are heads he he.

Jake

[AdamRRT]

That's funny. I talked to ICEM today about that same basic thing. Using the same principles we use on the dyno at Bluecat's. But he doesn't have time and I can't use his resources for it. And well honestly I don't grasp it well enough to get the timing reference just right. Thanks for seeing that, Rich. Very cool to hear you're on the case man!

[97singlecab]

so what is the max timing you guys are putting into these trucks? ive kept the max around 30. but i have seen múltiple files of 40 plus. just wondering what the consesis is

[06dodgecr]

You mean 30* no bias? im at 55* but with bias more like 35*

[2007 5.9]

I run no more than 45* (25* bias) on any of my trucks.

Haven't found any hp improvement over 45*.

~Les

[06dodgecr]

why a 25* bias? I thought it was discussed as a 20*?? what injectors do you run hole wise and pattern? I run the 7 hole bosch motorsport nozzle.

[AdamRRT]

Any update on the scope?

[2007 5.9]

I mean 25* with the 20* bias factored in.

And I'm running factory 5-hole 123* nozzles that are EH'd.

~Les

[FUBAR]

What percent extrude honed Les? Im think if doing the same thing since I won't be driving my truck for about a month. What kinda of turnaround time did you see?

[97singlecab]

The reason i ask is i ran a truck yesterday at 45 degrees and at 30 degrees timing. They made with in 10 hp of each other. biggest difference was egt's. at 45 degrees it pegs the gauge at 1600 almost instantly. at 30 it never goes over 1200 and makes the same power. I guess this timing bias just scares me a little, to put that much timing in with out knowing for certain what the bias actually is.

[AdamRRT]

FUBAR: I have my stock ones here. Just send them off and give me yours when you swap them out.
Or check prices. I think JL Machine will sell you some about as cheap as honing yours. Core charge exists I'm sure, of course.

[FUBAR]

Thanks Adam!!

[comnrailpwr]

FUBAR: i am very pleased with my extrude hone nozzles although i dont know how dirty thy would be on the street.

anyhow is there any new news on the timing bias??

[AdamRRT]

Along this topic line:

I've just set up to log data finally. Does the 20* apply to injector timing logging?

I assume it does but better ask. Haha. Thanks in advance guys.

[comnrailpwr]

Yes it does

Jake

[AdamRRT]

Yes it does

Jake

Thanks bro.

[Stealthdiesel]

Any updates on this issue?

[GMPX]

The next release (which is in beta now) has all the timing offsets resolved.

[DODGE74]

The next release (which is in beta now) has all the timing offsets resolved.

This is great news. Thanks Ross !


Thanks Adam!

[AdamRRT]

Ross. Lol.
So for those of us waiting, is it 20*? And did you ever get someone to scope it? I recall someone here was going to like 4wks ago, but that apparently fell thru. Anybody remember who it was that had the oscilloscope?

[GMPX]

Adam, for the 'real' value in the release you have -20 from everything you see, including the scantool. Every timing figure you see doesn't have the bias applied.
I know the scope was sent to someone but in the end I had a deep look at the maths in the ECM and there is a -20 deg bias offset throughout the system. I have no idea why as the ECM is using signed numbers for all timing values so it can go + or - anyway. It was actually whilst working on the 6.7L ECM (which has the same thing) it become obvious what the deal was.

[AdamRRT]

Oh man that's great. So we know it applies to the main injector base timing table.

Does it apply to:
Timing, Base Table, Air Density Adjust (1-4) E2500-E2502, E2504
Timing, Intake Air Temp Adjust D6264
Timing, Barometric Pressure Adjust D6267 (doesn't look like it applies here but I might as well ask)
Timing, Cranking D6258 (this looks like it definitely applies)
Timing, Minimum E2546 (this looks like it definitely applies)
Timing, Maximum E2549 (this looks like it definitely applies)

Thanks, Ross.
I know it LOOKS like it does or doesn't apply in these, but I just want to be sure rather than guessing. Thanks man.

[427lightning]

Thanks for the update Ross. Can't wait to get the new release once you get it done. I'd probably be more excited if I had an auto truck! Keep up the great work!