What kind of changes are needed to run speed density

[bwelch]

I have a 04 gto with afr heads fast 92mm intake comp cams 238/242 605/609 111 lsa 6 speed with 3.91. I am thinking about going mafless. What changes do I need to make on my tune to do so.

[limited cv8r]

I'm pretty sure the "auto VE" tutorial explains the steps to run mafless, plus other things.

[SSpdDmon]

SD changes required:

Flip MAF Fail frequencies: C2901 & C2904 (low becomes high and high becomes low)
Change Fail Limits to 1: C2903 & C2906
Copy High Octane Spark to Low Octane table
Change MIL Enablers C6002: P0101, P0102, P0103 = No MIL
(Don't change Processing Enablers)

That will put you in SD.

If you were going to tune with a WBO2, you would also want to go open loop.

Open loop tuning changes required:

Disable LTFTs - B3801
Disable STFTs - B4205 (set all to 283*F)
Adjust Commanded Fuel in Open Loop table - B3605 (set all rows 158*F and greater to stoich)
Adjust PE Based on RPM table - B3618 (set as desired for WOT)
Adjust PE Mode Enable - B3616 (adjust as desired by TP% & RPM when you want PE to activate)
Disable DFCO - B3313 & B3308 (set to 283*F)
Disable Cat. Overtemp Protection: B0701

[bwelch]

Thanks for the help.

[terryr85]

is it really that easy?

-sorry for diggin up old crap

[5.7ute]

Pretty much. If you arent using a COS you need to paste your high octane spark table to the low octane table since a fail mode kills the HO table.
Also if you are running an auto you need to prevent excessive line pressure etc, which again is caused from the pcm seeing a maf failure. These are in tables E0102,E0103 & E0104.

[Sid447]

..........Also if you are running an auto you need to prevent excessive line pressure etc, which again is caused from the pcm seeing a maf failure. These are in tables E0102,E0103 & E0104.

Learn something everyday!

I didn't know about these (I'm M6) are these changed to Yes? Maybe there's a thread explaining this a bit more?

[joecar]

Sid, those only apply to A4.

[Sid447]

Hello Joecar :)

Yes understand! But I'd like to broaden my horizon. Is there somewhere I can read up on this a bit more?

[joecar]

This is all we have so far: showthread.php?t=10773 (http://forum.efilive.com/showthread.php?t=10773)

Edit: link is now fixed... sorry about that... :doh2:

[5.7ute]

Learn something everyday!

I didn't know about these (I'm M6) are these changed to Yes? Maybe there's a thread explaining this a bit more?

Change these to No to disable max line pressure.

[Slowrc]

SD changes required:

Flip MAF Fail frequencies: C2901 & C2904 (low becomes high and high becomes low)
Change Fail Limits to 1: C2903 & C2906
Copy High Octane Spark to Low Octane table
Change MIL Enablers C6002: P0101, P0102, P0103 = No MIL
(Don't change Processing Enablers)

That will put you in SD.

If you were going to tune with a WBO2, you would also want to go open loop.

Open loop tuning changes required:

Disable LTFTs - B3801
Disable STFTs - B4205 (set all to 283*F)
Adjust Commanded Fuel in Open Loop table - B3605 (set all rows 158*F and greater to stoich)
Adjust PE Based on RPM table - B3618 (set as desired for WOT)
Adjust PE Mode Enable - B3616 (adjust as desired by TP% & RPM when you want PE to activate)
Disable DFCO - B3313 & B3308 (set to 283*F)
Disable Cat. Overtemp Protection: B0701



WHY would you not disable processing enablers??? Please, I have trouble popping codes for mil"s I have set to No mil

[joecar]

If you disable the processing enablers, then the MAF DTC's will not be triggered...

If the PCM does not see a MAF DTC, then it won't go to SD (VE only) mode...


i.e. when the PCM sees a MAF DTC, it fails over to SD mode.


i.e. the presence of P0101, P0102, P0103 signifies that the PCM is now running is SD mode.

[Sid447]

This is all we have so far: showthread.php?t=10773 (http://forum.efilive.com/showthread.php?t=10773)


Change these to No to disable max line pressure.




Thanks "Joecar" & "5.7ute."

:cheers:

[N0DIH]

What is GM's reasoning for the MAF tied to the transmission pressures?

I don't see the need. Isn't TPS fine for it? Or does it really use Calc Load and that is thrown off without a MAF so it goes max hard to make up for the lost value?

[joecar]

If airmass calculation is low, then commanded transmission pressure will be low, this allows clutches/bands to slip during high torque.


airmass -> calculated torque -> commanded line pressure

[N0DIH]

Are there any tables for it? On my L67 (3800 SC) I am on MAFless and having no problems with the trans with no MAF. All I can do is unplug the MAF and set the MAF Fail Low freq to 0.




If airmass calculation is low, then commanded transmission pressure will be low, this allows clutches/bands to slip during high torque.


airmass -> calculated torque -> commanded line pressure

[joecar]

Look for P0101,2,3 in tables E010x.

Some vehicles have those set to No

[N0DIH]

I set mine to NO when I killed off the MAF. It was bad and I figured it was a good time to tune without it and see.

Only problem I have is low airflow at low speed it stalls sometimes. I can't figure out what is up, even when driving, it almost seems like DFCO is set to aggressively. But it is set stock.



Look for P0101,2,3 in tables E010x.

Some vehicles have those set to No

[wesam]

SD changes required:

Flip MAF Fail frequencies: C2901 & C2904 (low becomes high and high becomes low)
Change Fail Limits to 1: C2903 & C2906
Copy High Octane Spark to Low Octane table
Change MIL Enablers C6002: P0101, P0102, P0103 = No MIL
(Don't change Processing Enablers)

That will put you in SD.

If you were going to tune with a WBO2, you would also want to go open loop.

Open loop tuning changes required:

Disable LTFTs - B3801
Disable STFTs - B4205 (set all to 283*F)
Adjust Commanded Fuel in Open Loop table - B3605 (set all rows 158*F and greater to stoich)
Adjust PE Based on RPM table - B3618 (set as desired for WOT)
Adjust PE Mode Enable - B3616 (adjust as desired by TP% & RPM when you want PE to activate)
Disable DFCO - B3313 & B3308 (set to 283*F)
Disable Cat. Overtemp Protection: B0701

could you illustrate this point
because in AutoVE tuning tutorial they did not say any thing about MAF low frequency

[WeathermanShawn]

wesam:

I have not seen SSpdDmon sign on this forum in awhile, so here is my view.

I don't believe you have to worry about C2904. I.E., I have failed the MAF just like AUTOVE states. I also don't change the Processing Enablers..you need to throw a DTC to be in SD.

Thats my understanding..:).

[wesam]

Thanks a lot Shwan

[Sid447]

Agree,

Just turning P0102 to NO MIL is sufficient. C2901 to 2910 can be left at factory parameters (this then allows you to run SD or maffed as you like).
Check the 2004 HSV GTS tune file in Holdencrazy which is single-spark SD.