Page 1 of 2 12 LastLast
Results 1 to 10 of 13

Thread: Supercharger/cam ignition timing

  1. #1
    New Member
    Join Date
    Aug 2013
    Posts
    8

    Default Supercharger/cam ignition timing

    So I am using the Diablo sport predator tune that came with my Supercharger as a base tune. So it is not adjusted for the cam that I'm running.

    According to the tune, they quit adding more fuel at 4800 rpm. My question is, now that I have adjusted for the fuel on the high end, do I need to change the spark timing more to maintain a rich mixture? My afr shows that around 5000 rpm it starts to lean out. It gets leaner then 15 at 5800 rpm. Any help and input would be appreciated. Also, do I need to adjust the pulse width of the injectors to accommodate for the higher lift and longer duration?

  2. #2
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    Add more fuel at higher rpm.

  3. #3
    New Member
    Join Date
    Aug 2013
    Posts
    8

    Default

    I'm already down to a .5 lambda and it's still running lean.

  4. #4
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    0.5 lambda from your wideband...?

    You said:
    My afr shows that around 5000 rpm it starts to lean out. It gets leaner than 15 at 5800 rpm.

    Post a log file.


    You need to set the IFR table (possibly scaled) and get VE and MAF tables corrected... then the commanded PE fuel will be what you get (measured with wideband).

  5. #5
    New Member
    Join Date
    Aug 2013
    Posts
    8

    Default

    No but the commanded fuel is at. 05. Idle and lower rpm is right around 14.2-15.2. Then under boost it richens up as its commanded to. But high end just kind of quits and starts to lean out. I'll get the tune from the guy that is helping me. He is more of a diesel tuner though...

  6. #6
    Lifetime Member limited cv8r's Avatar
    Join Date
    May 2005
    Posts
    567

    Default

    Has your fuel system been upgraded? Maybe your just running out of fuel?
    It's all good until it goes "Bang"

  7. #7
    New Member
    Join Date
    Aug 2013
    Posts
    8

    Default

    Right, I thought that I might just be running out but with what I'm running it should support around 525 horse at the flex plate and I don't think that I'm quite to that level of power

  8. #8
    Lifetime Member limited cv8r's Avatar
    Join Date
    May 2005
    Posts
    567

    Default

    What is your injector duty cycle & fuel pressure doing? They will be good indicators if you fuel system is lacking & your adding a lot of fuel to the tune & its not helping.
    It's all good until it goes "Bang"

  9. #9
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    Good point (thanks cv8r)...

    Kmb, describe your fuel system (from rear to front).

  10. #10
    New Member
    Join Date
    Aug 2013
    Posts
    8

    Default

    It is the factory flex fuel pump with factory rails and 42 lb high impedance injectors.

Page 1 of 2 12 LastLast

Similar Threads

  1. E38 6.0 Streetrod/Stanalone Swap - Very little ignition TIming
    By RdRacerZ28 in forum E37, E38 & E67 PFI ECM's
    Replies: 5
    Last Post: August 3rd, 2011, 11:10 AM
  2. Ignition timing issue,bank to bank
    By AllOutPerformance in forum Gen III V8 Specific
    Replies: 9
    Last Post: December 5th, 2009, 11:38 AM
  3. Ignition welcome message
    By stigmundfreud in forum General (Petrol, Gas, Ethanol)
    Replies: 0
    Last Post: March 29th, 2008, 10:39 AM
  4. B5154 VVT Cam Phaser Timing
    By MN C5 in forum Gen IV V8 Specific
    Replies: 2
    Last Post: February 13th, 2008, 08:15 AM
  5. Ignition Timing
    By VetPet in forum General (Petrol, Gas, Ethanol)
    Replies: 3
    Last Post: May 30th, 2006, 02:47 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •