MAP or MAF for timing

[Dave Lewis]

Does the Duramax use the MAF or MAP for timing? Looking at B0901 on my stock tune it is set to MAP. I would have thought it should be using MAF. Please forgive my ignorance.:hihi:

[GMPX]

Dave, all the GM files I've seen are using MAP (actually Baro), reason?, not sure.
You can confirm this by the fact the A,B,C load points for the MAF are all set to 32 as well as the MAP selection.

Well, thinking about it, if set to Baro that gives you 3 timing tables to compensate for Baro differences, but if you set it to MAF you could have 3 timing tables based on load.....that to me sounds like a much better option as far as when these engines are being pushed way above the power levels GM would have tuned for, the only problem is you then loose Baro timing compensation because there is no Baro based timing table.
That might very well be an issue for someone who lives up in the clouds.

Cheers,
Ross

[GMC-2002-Dmax]

Use Injection Timing MAP "C" as it is in effect above 162 degrees.

The other MAPS "A" and "B" are used for lower temps and then use multipliers for BARO and Fuel Temp to further alter timing if necessary.....but the multipliers do not effect anything over 132 degrees and the factor is ZERO so it does not effect timing anymore.

If it rattles you have too much timing..........or you might want to move pilot timing closer to main injection timing..........use PILOT Timing table "C" for 155 degress to 162 degrees and "D" for 162 degrees and over.......

You would be surprised how different the truck reacts and the motor reacts to pilot timing........:)

If you need any help you have my email and you can PM me,

T:eek: NY

[Dave Lewis]

Awesome, Thanks. Now if it would quit snowing.

[GMPX]

You would be surprised how different the truck reacts and the motor reacts to pilot timing........:)


You mean, you can make it sound like a Powerstroke :hihi:

Cheers,
Ross

[dfe1]

You mean, you can make it sound like a Powerstroke :hihi:

Cheers,
Ross

That's "Powersmoke"

[Max Power]

You mean "PowderStroke"

[GMPX]

"Powerjoke", keep em coming, where a happy GM family around here :hihi:

Cheers,
Ross

[Max Power]

Hey did you hear Ford found the problem? Yep, they even circled it!

http://www.lakenorman.com/images/sponsorPages/3153/Ford_oval.jpg

[joecar]

Found On Road, Dead. :hihi::hihi::hihi::hihi:

[dfe1]

Then there's always the old standbys- Fix Or Repair Daily and First On Race Day. Although Ford folk will disagree, I thing "First" refers to the DNF list, not the winner's circle.

[kbracing96]

And backwards, it "Driver Returns On Foot" :)

[Max Power]

Did you hear Ford is putting heated tailgates on their 6.0L's as a new option?


That way you won't freeze your hands when your pushing it to the side of the road :D

[GMPX]

Good to see this thread is sticking to it's original topic :rolleyes:
It is funny though.

Cheers,
Ross

[joecar]

Ross, age and/or insanity have dealt us a soft blow, we can't focus anymore...:hihi: ...what was it that you said...? :D

[Max Power]

I was analyzing the thread and I am pretty sure I found the post that through if off course.

"Powerjoke", keep em coming, where a happy GM family around here :hihi:

Cheers,
Ross

[dfe1]

As long as we're careening around off topic, here's a great story (true, by the way). A friend of mine (driving a Duramax) was towing a 28-foot enclosed trailer on the Interstate and pulled along side a guy in a Powersmoke (who wasn't towing anything). The Powersmoke driver looked over, saw the "Duramax" logo on the side of the truck and pushed the accelerator pedal to the floor. My friend did the same thing and he said it was really funny to watch the Powersmoke driver's jaw drop when the guy realized he was being passed by a Duramax-- towing a trailer.

[Max Power]

It happens quite often, trust me :D

[cured5.7]

So was that MAP or MAF for timing ??????????????? lol
Found
On
Rubbish
Dump

[lakingslayer]

I'm just trying to understand here. Is there a PID that measures MAF the can be equated to the B0902 table? Looking at this stuff it looks like the 32grams is quite large for what I can measure on the PID (g/s).

Sorry go off topic again.:smile:

[GMPX]

With all 3 values set like that it is basically disabled.
But B0901 dictates which is used, MAP or MAF.

Cheers,
Ross

[Dieselholic]

Ross,

I noticed while trying to enable the 3 timing tables via the MAF setting that the highest MAF value that will be accepted is 32 g/sec. on my '02 & '03 O.S.
However on my '01 O.S. it will accept MAF values up to 256 g/sec. not sure why that is, 256 is better than 32...but it could be higher still, couldn't it?:help2:

P.S. This stuff is so much fun it should be illegal?:coool: :wink:

Thanks, Todd.

[GMPX]

Mmmm, the 02/03 O.S should not be limiting the value to 32, we will look into that.

Cheers,
Ross

[lakingslayer]

Mmmm, the 02/03 O.S should not be limiting the value to 32, we will look into that.

Cheers,
Ross
'04 LLY also has this problem...at least mine does. I only mention that here for the LLY so you don't have to follow two treads.

[Danville Performance]

Flip
Over
Read
Directions

Doesn't
It
Equal
Slow
Especially
Loaded

[Dieselholic]

Ross,

Just curoius if you were able to sort out the irregular(& low) mass airflow values regarding the timing table switching? It really is a great feature if it can be utilized fully, I've played with it in the '01 O.S. Even more range (say 512) would be excellent their as well though.

Keep up the great work,
you guys rock, Todd.:)

[GMPX]

GM changed the code, I guess they decided they would be using MAP all the time so they made a change to the MAF setting with the result that the highest value is much less than what it used to be.

Cheers,
Ross