Parameters changed for performance.

[Redline Motorsports]

The following are the parameters that are changed for performance. What they all do I have no idea!!

B0720 Main Injection Pulse
B0721 Main Injection Pulse (no Pilot)
B0910 Injection Timing (C)
B0927 Injection Timing after Pilot (B)
B0928 Injection Timing after Pilot (C)
B1101 Peak Torque
B0725 RPM Limit (upper)
B0726 RPM Limit (lower)
H0107 Vehicle Speed Limit (upper)

Anyone know what the (A) (B) and (C) represent? Also can we control the variable pitch blades of the turbo??

This is going to be crazy!

Howard

[a78turbo]

A,B,C are different the Temps or MAP/MAF readings that affect fueling. "A" may be from 0 deg to 70 deg engine temp. "B" from 70deg to 145deg, then "C" 145deg to 230deg. different stages of control. Also same for MAP/MAF readings. Yes, you can change turbo nozzle (pitch) settings also. Biggest thing is to take small steps, though. Lots of changes available.
P.S. Have fun! :cheers:

[Wasted Income]

The following are the parameters that are changed for performance. What they all do I have no idea!!

B0720 Main Injection Pulse
B0721 Main Injection Pulse (no Pilot)
B0910 Injection Timing (C)
B0927 Injection Timing after Pilot (B)
B0928 Injection Timing after Pilot (C)
B1101 Peak Torque
B0725 RPM Limit (upper)
B0726 RPM Limit (lower)
H0107 Vehicle Speed Limit (upper)

Anyone know what the (A) (B) and (C) represent? Also can we control the variable pitch blades of the turbo??

This is going to be crazy!

Howard

Thanks a TON Howard! :master:

[GMPX]

B0720 Main Injection Pulse
B0721 Main Injection Pulse (no Pilot)

Defines the 'open' time of the injector based on the commanded fuel quantity and desired fuel pressure.
Commanded fuel quantity is based on the throttle position and various torque reductions etc.



B0910 Injection Timing (C)
B0927 Injection Timing after Pilot (B)
B0928 Injection Timing after Pilot (C)

Simply changes the time the fuel is injected, I guess you can think of this similar to spark timing for gas in that this can hurt a Diesel motor, if the timing is wrong they do get noisy.



Anyone know what the (A) (B) and (C) represent?

The ECM switches to different (A), (B), (C), sometimes (D) maps usually based on coolant temp or baro or load.



Also can we control the variable pitch blades of the turbo??

Yes, look under the boost settings, desired target positions :hihi: .



This is going to be crazy!

Howard

Yes, it's amazing what can be done to these engines.
It takes some time to get your head around how the table structures work and how each one ties in with the others as it is totally different to what we are used to with the LS1.
But when it all 'clicks' they are done in a very logical fashion.

Have fun....
Ross

[Dave Lewis]

Ross,

How do the several timing maps inter-relate? For example, if using timing map C how do the temperature maps change this value. I assume the temperature maps would be subtracted from the timing maps? Are there any flow charts that show the interaction of all the maps?


I do have to say this is fun, fun, fun.

Dave

[Racehemi]

I didn't find any flow charts so I drew mine own on scratch paper, then using results from scan data I calculated and compared numbers until it made some sense to the cranium. In the first two weeks I easily spent 40-50 hours, if not more, playing with EFILive plus working my day job.

[Redline Motorsports]

Ross,

Thanks for the clarifications! I noticed that my Duramax seems to be making the same boost regardless of which hp setting is used. It is interesting that just fuel alone makes the power increase. What if the boost got increased and we fed it more fuel?? This thing is making between 15-22 psi but I have heard of guys making between 30-35. What parameters effect boost increase/decreases? What are safe levels of change?

What is the pilot?

Nice job on the Flashscan dashboard!:cheers:

Howard

[GMPX]

Ross,

How do the several timing maps inter-relate? For example, if using timing map C how do the temperature maps change this value. I assume the temperature maps would be subtracted from the timing maps? Are there any flow charts that show the interaction of all the maps?


I do have to say this is fun, fun, fun.

Dave

You almost do need a flow chart, but basically -
B0908, B0909 & B0910 are your base maps, the ECM will switch between them based on baro or load (MAF), look at B0901 to B0907.

Then these values are further modified by the ECT, IAT and Fuel Temp tables. The values from those tables are added on to the base table.
The ECT tables are again selected based on baro or load (MAF). Then to add a bit more confusion, each one of these tables has a multiplier. Look at the Fuel Temp timing multiplier table B0920. It only has any affect when the fuel temp gets hot (multiplier becomes 1).
It appears confusing at first but it is a very good way of doing things, it gives GM an enormous amount of adjustment.

Hope that helps.

Cheers,
Ross

[GMPX]

Ross,

Thanks for the clarifications! I noticed that my Duramax seems to be making the same boost regardless of which hp setting is used. It is interesting that just fuel alone makes the power increase. What if the boost got increased and we fed it more fuel?? This thing is making between 15-22 psi but I have heard of guys making between 30-35. What parameters effect boost increase/decreases? What are safe levels of change?

What is the pilot?

Nice job on the Flashscan dashboard!:cheers:

Howard

Howard,

One of our beta testers did alot of messing around with he's LLY and boost settings, hopefully he might chime in and offer some advice. Though I think he said the desired boost levels had more effect than altering the turbo vane position tables.

The pilot injection is just a small amount of fuel that gets injected before the main pulse. It helps make the engine quieter and also helps ensure the main pulse is also ignited fully. If you do a google search on pilot injection there is plenty of info out on the internet.

Thank Chad (Black02SS) for the dash, he certainly did do a nice job.

Cheers,
Ross

[bobo]

Before changing the boost levels, you must turn off the EGR. Here is what ya do:

Set B1502 to 0. Set B1503 to 8000. The EGR will never come on. You also need to set the DTC'S Processing Enablers to X: Not Reported for P0401,p0403,p0404,p0405,and p0406. This will eliminate the EGR test at start up that could set a code from shutting the EGR off or having too much boost during the startup test. Doing these few tasks will completely disable the EGR. EGR will remain closed at all times. You can log it to prove it to yourself also. You need to select the desired pid (an EGR pid) and record the data.

[Wasted Income]

Before changing the boost levels, you must turn off the EGR. Here is what ya do:

Set B1502 to 0. Set B1503 to 8000. The EGR will never come on. You also need to set the DTC'S Processing Enablers to X: Not Reported for P0401,p0403,p0404,p0405,and p0406. This will eliminate the EGR test at start up that could set a code from shutting the EGR off or having too much boost during the startup test. Doing these few tasks will completely disable the EGR. EGR will remain closed at all times. You can log it to prove it to yourself also. You need to select the desired pid (an EGR pid) and record the data.

So Bob, if I'm thinking correctly, I should now be able to remove my blocker plate and Fingerstick, right? :thankyou2:

[Max Power]

I would leave the blocker plate but you can definately get rid of the fingers stick.

[bobo]

I pulled my blocker plate. I have not seen the EGR open on any of my logs w/ it shut off the way I posted. Max, why leave the plate in?

[Fingers]

If you play with boost, the drive pressure will be enough to crack open the EGR.

[Kennedy Diesel]

I've never had a blocker in mine. Guess I'll need to check it out...

[Wasted Income]

Hmm, lots of good info here. Thanks guys.

[Fingers]

I should elaborate. LLY only.

With somewhere around 70 - 80 PSI of back pressure in the exhaust there is enough force on the EGR valve to overcome the spring. Boost on the other side will help keep it closed. So once boost builds, the valve shouldn't open. On big tunes with agressive, rapid spool up off idle, you can catch the EGR popping. Keep in mind that once it pops, it pressurizes the intake and provides false boost. So it will actually flutter more than pop. You can hear it when it happens.

There is no power here with the stock turbo, or any benefit that I can see being this agressive, The spool up is the same or worse. The extra back pressure actually hinders the engine making power all the way up the curve.

[Redline Motorsports]

I should elaborate. LLY only.

With somewhere around 70 - 80 PSI of back pressure in the exhaust there is enough force on the EGR valve to overcome the spring. Boost on the other side will help keep it closed. So once boost builds, the valve shouldn't open. On big tunes with agressive, rapid spool up off idle, you can catch the EGR popping. Keep in mind that once it pops, it pressurizes the intake and provides false boost. So it will actually flutter more than pop. You can hear it when it happens.

There is no power here with the stock turbo, or any benefit that I can see being this agressive, The spool up is the same or worse. The extra back pressure actually hinders the engine making power all the way up the curve.

70-80 psi of back pressure in the exhaust? :Eyecrazy: Wow that sounds like a lot!

Wouldn't you want to get rid of thatkind of BP with a decent exhaust system? I assume that when the main pulse width is increased the additional fuel helps create a large combustion cycle that will help the turbo spool up. How do we get more boost?

[bobo]

The best way to get rid of the excess back psi would be to upgrade the stock VVT turbo. It is the root cause of the problem.

[bobo]

:welcome: Ohh, and Welcome Fingers!!! You have forgoten more about this motor than I will ever know. Good to see you here and thanks for the input!!

[Fingers]

I should say "drive pressure" instead of just back pressure. My bad. Drive pressure is between the turbo and engine (technically back pressure) and is a necessary evil to make boost. How much evil is another story. A better flowing exhuast helps to a point.

Bobo is right, a larger VVT would help out a lot here.

[GMPX]

Bobo is right, a larger VVT would help out a lot here.

Pardon my ignorance....do larger ones exist?, VVT seems like a good thing to me.

Cheers,
Ross

[Redline Motorsports]

Does anyone make a nice replacement turbo for these trucks without major modifications? Now that the tuning is available, it would be much easier to go to a slightly larger turbo.

[bobo]

IMHO: BD turbo is your best shot. It isn't a VVT, but there isn't a bigger VVT out on the market than stock. McRat tried the new LBZ VVT on his 05 LLY. He didn't notice much more than the stock LLY turbo. You could also look into the Aurora 2000 or 5000. The 2000 is just a bit bigger than the stock LB7 turbo, but don't flow as much air as the BD. The 5000 is the big boy of the bunch, but requires head studs, injectors, and possibly CP3 modifications. Tomack runs the 5000. He is putting down around 600-650rwhp on fuel only (12 flat at 7000# in the 1/4). I'm sure the BD is good for 600rwhp(I seen an LB7 run three 13.3 passes w/ 2.0 60ft times on a hot juice alone w/ BD turbo installed) and the 2000 is good for 550. Bang for the buck the BD takes it hands down. ATS is introducing the hybrid VNT (Variable Nozzle Turbo). This has not been proved and is a new engineering concept that has finally been released to the public. I would not mess w/ it yet. I'll let the "twins" folk explain your options there. They are having very good results on the LLY w/ twins.

[Redline Motorsports]

IMHO: BD turbo is your best shot. It isn't a VVT, but there isn't a bigger VVT out on the market than stock. McRat tried the new LBZ VVT on his 05 LLY. He didn't notice much more than the stock LLY turbo. You could also look into the Aurora 2000 or 5000. The 2000 is just a bit bigger than the stock LB7 turbo, but don't flow as much air as the BD. The 5000 is the big boy of the bunch, but requires head studs, injectors, and possibly CP3 modifications. Tomack runs the 5000. He is putting down around 600-650rwhp on fuel only (12 flat at 7000# in the 1/4). I'm sure the BD is good for 600rwhp(I seen an LB7 run three 13.3 passes w/ 2.0 60ft times on a hot juice alone w/ BD turbo installed) and the 2000 is good for 550. Bang for the buck the BD takes it hands down. ATS is introducing the hybrid VNT (Variable Nozzle Turbo). This has not been proved and is a new engineering concept that has finally been released to the public. I would not mess w/ it yet. I'll let the "twins" folk explain your options there. They are having very good results on the LLY w/ twins.

Thanks for this info! I am not looking to go nuts its still a "daily driver". My Corvettes feed my speed appetite! I was hoping there was a nice replacemenet turbo to step it up a bit. Now that the tuning is here, and working, I am kind of interested in fooling around with the truck. I'll look into the options you noted. I have already gone 14.60 in my 4wd crew cab which I though was funny as hell for a 7000 lb truck!:Eyecrazy:

[Fingers]

Pardon my ignorance....do larger ones exist?, VVT seems like a good thing to me.

Cheers,
Ross

Nothing bigger right now, but I am working on that. These turbos share some parts with others and function the same from a controls point of view to almost any VVT.


VVT can be, and is, very effective in other applications. However, to take full advantage, we need some logic changes to the OS.