Help a brother out with 01 diesel tuning

[04snake]

I finally got to see a stock T D tune ( thanks to Ted Jannetty ) and it seems the idea of tweaking a Turbo Diesel is real popular with my mechanic buddies who all seem to own one so I have a friends 01 that I am going to try to experiment with Monday.

well I'm somewhat experienced with gassers but total noob with the glow plug crowd, so where can you find a couple HP? Are there any write-ups, maybe for other software to get the basics down? I can handle the Trani changes but where do you go for the motor fine tuning? It is a MAF only system from what I can see, so I'm at home with that Ford like air metering but what AFR am I aiming for? It isn't a closed loop system with no O2 or other sensors or a Stoimetric constant, is it? So this is old school, run it open loop all the time, right? Is leaner more power or richer more power? Sorry for being a tard but I have never owned one.

chuck me a few basics and I'll figure the rest out on this truck I have to experiment on. Man the demand for a non-parasitic tuning option for these guys is pretty darn strong, two other guys (one has a 06) are ready to step up next if I can give this guy a more fun truck to drive. I didn't want to pester guys with PM's because I realize everybody is trying to learn as fast as possible, but catch me up a smidge and maybe I can help contribute to the knowledge base. I know I'll be up all night again searching around for deisel info but need to WOT tune my SS right now, thanks in advance any help you can spare.

just a quick aside here, you guys may not know how good you have it with this version of the HP Tuners, very easy to use and things are setup with a lot of thought. It smokes SCT and Diablo, the two packages I have seen and used, just not even in the same league, but I'm sure Keith has heard that before.

- stu

[JANNETTYRACING]

Your welcome on the stock file.

A Few Basics to keep in mind.
More fuel equals more power but more heat.
Boost cools a Diesel and supports the fueling to keep EGT in check.
1350 Pre turbo EGT is Safe MAX.
More timing increases cylinder pressure and lowers EGT but slows Turbo response and increases NOX emissions.
Tune using EGT and tail pipe emissions, contrary to popular belief you don't want to see any smoke under power maybe a little on initial tip in of the throttle.
If you increase fuel you must balance it with more boost/air.

Hope this helps

[Bill@HPTuners]

thanks for the tips JR

[04snake]

Ted,

Thanks a ton, yeah I had a few of those goals in mind this morning, the info is duly noted and much appreciated! You are a resource over on modfords I listen to and value all your opinions and help and it seems you beat me to the GM tuning as well. they are lucky to have you over here for the experience you bring along with you.

foff667,

You are the MAN! You bailed me out this morning, I was up to 3am going over my race logs from my SS and had no time for a proper tune so I dragged my tired butt to the shop and I followed the quick steps from McRat you pointed me to. It slapped in a quick and dirty 50HP/80TQ or so with a couple of hacks and tricks played on the VCM. This is the first official "hack " tune for me but I licensed the vehicle and told the guy if he still lets me experiment on him I will replace it with a proper tune, if what he has isn't enough but after he laid down 4 15ft burnout marks with the same 3500 9000lb crewcab dually that would only chirp the tires after heavy brake boosting, I doubt if he will want much more power, he uses it to tow heavy equipment, no street racing or track, but you never know.

McRat,

It was your 3-step program I employed in a pinch, even though one of the 3 changes I couldn't really figure out the why for, but it all seemed to work great and will buy me some time so I can dig deeper into these glowplugs, heck after seeing how easy it was to turn up the wick it looks like my new truck next year will have to be a Duramax, hopefully by then they will have an update to allow tuning of LBZ's ( I'm still working keeping LB7/LLY/LBZ straight). Glad to see you are a member here, so I can pester you a bit. Not sure if you tune Fords, but I can return the favor on blue oval tuning, if you ever have a question about them, poly not, but keep it in mind.

here is what I did, 3 easy steps in the McRat plan:

1.) I fooled the VCM by increasing the Main Inj PW & Main (no pilot) by 20% to trick into thinking it had larger injectors, I will put this back to stock when I tackle reshaping the Base Fuel tables, but for now I hacked it up a little. The steps I followed only talked about 2 tables but HPT sees three. What is the Pilot PW for? I couldn't figure out if one was the Performance profile or what, I may have to add 20% there too but I wanted to understand their relationship better and when which is used and why.

2.) I bumped the base injector timing by copying the high altitude table (base baro low) with higher GM mapped timings to the medium and high barometric tables. Seemed like that would be safe and the truck sounded 100% normal when he goes WOT.

3.) **NOTE** The following trick only applies to the LLY motor, not the LB7 Waste-gated motor I was working on (always helps to know what your working on) so I put it back to stock after realizing it wasn't what I needed to do. The hack to make 20% more boost on a LLY is to removed 20% from the desired boost max calibration table above 1000rpm and smooth the transition. The goal was not to mess with idle and very low load, only when there is real boost. I believe the idea is to fool the VCM into thinking there is less boost then there is, so it continues to make more, even beyond the factory limits but forget this if you have a LB7 and be happy with the first two hacks, they will make a noticable improvement.

those hacks will screw up your mileage calcs and the boost logs will report 20% less boost, so I think it was topping out around 23.5 psi (reading 19.5) but that is basically what most piggy back tuners do and they screw up some of the same stuff. I did find out that most people agree that you can go up to 25psi without much risk, so I felt 23 was not to aggresive. I also upped the TQ max and modified his non-Tow trani profile to shift 10% faster but left the GM Tow trani stuff alone until I can dig into the pressures maps and shift points. The owner said it was running a lot stronger, like night and day so he will do some real world testing and report back. I rode along and logged what I could find that made sense but there seems to be some pids missing, is there going to be a new version of the Scanner coming out? Do LLY's and LBZ's have factory EGT's or is that something that has to be added? I couldn't find a downstream IAT listed anywhere either, kinda odd for an intercooled boost system.

I am not a hack tuner, I really dislike the hacks but sometimes you just need to get the ball rolling. I did everything the right way on my Cobra and it is a monster and it seems after a couple of street pulls and 3 track passes I have a solid flat safe 13.0 race tune for my new peppy SS that sees a full 28.5* at 6K doing it all the right way. I'm not sure if I will be able to resist re-tuning this first 01 LB7 Duramax the right way once I learn a little more, but I might get the urge. The line of guys wanting their trucks just gets longer so I'll have other chances. Diesels seem to have a lot less to deal with actually, but maybe we are not seeing all the tables yet in this version, dunno but at least my glowplug cherry has been busted and the owner was beside himself.

Diesel and gas have similar lambda’s of 14.6 but does AFR have no role to play at WOT for diesel tuning, just keep pouring the fuel in and hope your MAF and VE tables are properly calibrated? I know EGT gives you indirect info about how lean you are, but how do you calibrate the MAF without some feedback, do you need an EGT? I see in the scanner where you can add a user defined EGT, but didn't see a VCM GM pid for it? I logged Main vs Pilot PW, InjTime and Fuel, but only InjTime shows the Pilot jumping up higher than main during initial load and that was with/without the Tow mode being on, so that made me think it has some other purpose, just I don't know what exactly and the help file was a little light for these new PIDs.

Well I attached the diffs, the scanner config I slapped together in a hurry and a log file and would be very open to suggestions as to what to add to scan or what the logs might hold, everything commanded is close to the actual for the few pids available to scan.

Thanks to everybody for the help and hope I can return the favor, somehow, somewhere. I uploaded the 2001 stock Duramax tune if anybody else wants to poke around in there.

- stu

[JANNETTYRACING]

Pilot pulse is to quiet the engine ( Diesel Rattle ) This is what makes them so quiet, you will notice at about 2600 the pilot injection shuts down the engine gets a lot louder.
Some engines use 3 pulses Pre, Main, and Post injection.
Pre is for noise, Main is for power, and Post is to heat the cat converter.
Timing is adjustable for all three separately.
The new engines for 07 may have up to 6 pulses per event all in a effort to clean up emissions and reduce noise.

I am not sure yet, Maybe Chris can Chime in but when you see Low Med and High Baro I think it means boost above atmospheric.

I will comment on A/F later it is too early and I am experiencing a mental block.

EGT is a powerful tuning tool on a Diesel and you must add an aux probe and hook it in to your interface or run a separate gauge.

Not sure what you meant by this.

I then did another hack to make 20% more boost, I removed 20% from the desired boost max calibration table above 1000rpm and smoothed the transition. The goal was not to mess with idle and very low load, only when there is real boost. The VCM thinks there is less boost then there is, so it continues to make more, even beyond the factory limits.

Are you working on an LB7 or LLY you didn't say.

[JakeGMCHD]

AFR has no effect on diesel tuning. AFR on a diesel is constantly changing. Yes, you should tune with an EGT gauge. You can use the VCM Scanner to map out your new MAF table that your new tune needs. None of the Duramax engines come with a factory EGT gauge.

[Bill@HPTuners]

if what he has isn't enough but after he laid down 4 15ft burnout marks with the same 3500 9000lb crewcab dually that would only chirp the tires after heavy brake boosting, I doubt if he will want much more power,

Nice glad it worked out for ya...I don't know crap about diesel tuning OTHER then afr really doesnt matter & that most diesel motors are built to withstand the test of time(cant say the same for their trannies though)

[McRat]

...
1.) I fooled the VCM by increasing the Main Inj PW & Main (no pilot) by 20% to trick into thinking it had larger injectors, I will put this back to stock when I tackle reshaping the Base Fuel tables, but for now I hacked it up a little. The steps I followed only talked about 2 tables but HPT sees three. What is the Pilot PW for? I couldn't figure out if one was the Performance profile or what, I may have to add 20% there too but I wanted to understand their relationship better and when which is used and why.

2.) I bumped the base injector timing by copying the high altitude table (base baro low) with higher GM mapped timings to the medium and high barometric tables. Seemed like that would be safe and the truck sounded 100% normal when he goes WOT.

3.) I then did another hack to make 20% more boost, I removed 20% from the desired boost max calibration table above 1000rpm and smoothed the transition. The goal was not to mess with idle and very low load, only when there is real boost. The VCM thinks there is less boost then there is, so it continues to make more, even beyond the factory limits.

...

That sounds great! Do you mind if I use that?

[04snake]

working on a 01 LLY, to tell the truth I didn't follow why to reduce the boost table would fool it into think it was making less boost than it actually was and that would fake it into making overboost. The instructions were taliored for EfI and the only boost table I could find was that one, I might be all wrong on that one, I mean it has a map sensor it can see so?? I am seeing 19.5 lbs after subtracting one atmos but the claim was it was actually making 20% more than reported, but I admit it doesn't make sense to me. Now if the max that an LLY will make is 19.5, which is what I think those puppies make from the factory, then that didn't change, it sees it everytime you step on it but more power is coming from somewhere?

Pilot pulse is to quiet the engine ( Diesel Rattle ) This is what makes them so quiet, you will notice at about 2600 the pilot injection shuts down the engine gets a lot louder.
Some engines use 3 pulses Pre, Main, and Post injection.
Pre is for noise, Main is for power, and Post is to heat the cat converter.
Timing is adjustable for all three separately.
The new engines for 07 may have up to 6 pulses per event all in a effort to clean up emissions and reduce noise.

I am not sure yet, Maybe Chris can Chime in but when you see Low Med and High Baro I think it means boost above atmospheric.

I will comment on A/F later it is too early and I am experiencing a mental block.

EGT is a powerful tuning tool on a Diesel and you must add an aux probe and hook it in to your interface or run a separate gauge.

Not sure what you meant by this.



Are you working on an LB7 or LLY you didn't say.

[Bill@HPTuners]

That sounds great! Do you mind if I use that?

and I followed the quick steps from McRat you pointed me to.

[04snake]

That sounds great! Do you mind if I use that?

Hey dude, I gave credit, didn't I?? LOL!!!


so inquiring minds want to know, how does reducing the max boost table fool it into making more boost, I'm having some conceptual problems with that but I have a 50 YO brain and it is slow to grasp.

I'll tell you one thing though, the 2001 LLY ran like a raped ape after following your 3-step plan there and if you could have seen the look on the owners face, I could tell the truck woke the F up!!

could I send you my boost table to see if I smoothed out correctly, that is an artistic talent, I'm not sure I am that great at.

[Trippin]

That sounds great! Do you mind if I use that?

Lots of good stuff to learn at the McRat site.

[McRat]

Uh... There is no 2001 LLY.

2001-2004 - LB7: IHI Charger, waste-gated, hidden injectors, first gen ECM.
2004.5-2005 - LLY: Garrett VNT charger, exposed injectors, 2nd gen ECM.
2006-2007 - (fake LLY) LBZ: Garrett VNT, exposed injectors, no ICM, 3rd gen ECM.


Pat

PS - Sorry, it sounded like you were saying thanks to someone else.

[Bill@HPTuners]

Just to clarify I pointed him in the direction of your posts over on www.dieselplace.com because as of right now they are the easiest most comprehensive out there. Even though they were origonally intended for use with efilive thankfully hptuners has the same tables as far as I could tell meaning most of the same adjustments can carry over. Thanks McRat for your writeup's...apparently they work very well

[WS6FirebirdTA00]

great info

[04snake]

Uh... There is no 2001 LLY.

2001-2004 - LB7: IHI Charger, waste-gated, hidden injectors, first gen ECM.
2004.5-2005 - LLY: Garrett VNT charger, exposed injectors, 2nd gen ECM.
2006-2007 - (fake LLY) LBZ: Garrett VNT, exposed injectors, no ICM, 3rd gen ECM.


Pat

PS - Sorry, it sounded like you were saying thanks to someone else.

well it was a 2001, so I guess I messed up and will put the boost table back to stock. The shop owner, whose brother inlaw's truck we were working on told me it was an LLY and he owns a LBZ, so I relied on him to know the right motor code. I don't know squat about Diesel's so who am I to argue, so the lesson learned is haste makes mistakes and don't trust anybody.

So Pat,

could you pretty please explain to me how that would work on a LLY anyway? Is the fact that it doesn't have a dumb Wastegate mean that boost blowoff is computer controlled so lowering the max boost table to fool the ECM works by the fact it thinks reported boost is actually 20% higher than what it thinks it sees? I know it is a fake out hack, but after reading your original thread several times, for the life of me I couldn't find the logic in it, but I'm sure I am just light in the basics of this type of boosted system. My track car is supercharged, so I have dealt with boost and boost blow off, I guess I am just having a mental block there.

[04snake]

Pilot pulse is to quiet the engine ( Diesel Rattle ) This is what makes them so quiet, you will notice at about 2600 the pilot injection shuts down the engine gets a lot louder.
Some engines use 3 pulses Pre, Main, and Post injection.
Pre is for noise, Main is for power, and Post is to heat the cat converter.
Timing is adjustable for all three separately.
The new engines for 07 may have up to 6 pulses per event all in a effort to clean up emissions and reduce noise.

I am not sure yet, Maybe Chris can Chime in but when you see Low Med and High Baro I think it means boost above atmospheric.

I will comment on A/F later it is too early and I am experiencing a mental block.

EGT is a powerful tuning tool on a Diesel and you must add an aux probe and hook it in to your interface or run a separate gauge.

Not sure what you meant by this.

Are you working on an LB7 or LLY you didn't say.

LB7/LLY I thought it was an LLY, but I was wrong, heck I had about 12 hours to learn all about GM Turbo Trucks, so I'm sure there was plenty more I didn't know but I'm a quick learner.

thanks Ned, I think I am beginning to have a grasp on the different injection events now, the Pilot injection happens first, staggered ahead of the main injection to minimize the death rattle and that is triggered under 2600 rpm or so when other parameters are also met. While Pilot injection is being commanded the primary power injection event is controlled by the Main Injector PW table, when the truck is then above 2600 and moving with less load the Main Injection PW (NO Pilot) table is the only one in use. I bumped the PW up on those two MAIN power tables and left the Pilot PW table alone. You would only mess with that if the death rattle is too loud, right?

What I didn't see on this 01 was a post injection table. Is the time between PW events controlled by the Interval tables, I didn't see separate timing tables so I'm guessing?

Your an East Coaster like me, I hope to meet up at the track someday so I can buy you a Coke and some track fries!

By the way I submited the 01 stock tune, but it isn't available in the repository yet, so here it is for inquiring minds. It is significantly different from the 04-05 LLY stock tune, even a noob like me can see that! 69 differences to be exact, but most are minor, still pretty interesting.

[JANNETTYRACING]

There are no post injection events on the LB7 or LLY maybe on the LBZ but who knows right now.

On the LB7 I believe Pilot injection is used all the time but on the LLY it is not.

Under Engine/Fuel Control/Diesel/Pilot fuel quantity, there is a parameter the determines above or below fuel mm3 that Pilot injection is allowed.

Ted not Ned.

[04snake]

here is a log from a WOT punch on the 01 I tinkered with. You can see how all the events line up and interact, it helped me figure it out anyway.



I know your name is Ted, I really need to read what I post a little closer! no joke, growing old sucks. Sorry bout that.

[nsracer]

Is the fact that it doesn't have a dumb Wastegate mean that boost blowoff is computer controlled so lowering the max boost table to fool the ECM works by the fact it thinks reported boost is actually 20% higher than what it thinks it sees?

Pretty much! LLY Duramax uses a variable geometry turbo - no wastegate (computer controlled vanes - basically like being able to constantly change the A/R). No vacuum on Diesels so no blowoff valve.

Anyway, what you're doing is basically making the ECM think the engine is seeing 20% less boost than the turbo is actually producing - ECM commands more boost to compensate and wala! More boost!