Page 1 of 2 12 LastLast
Results 1 to 10 of 15

Thread: Just one question for now?

  1. #1
    Junior Member
    Join Date
    May 2012
    Posts
    32

    Default Just one question for now?

    Hello everyone.

    LS2 engine with E40 pcm in Australian VZ clubsport.

    My question is in relation to table B3671. The original tune has 14.7 across the board to reflect the stoichiometric ratio of normal unleaded fuel,
    however I am using premium shell unleaded 98 ron which supposedly has a stoichiometric of 14.35. Should this be the value that I populate in that table.

    Thanks again .

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

    Default

    Try it and observe the LTFT's... compare them before/after.

  3. #3
    Junior Member
    Join Date
    May 2012
    Posts
    32

    Default

    Thanks, ill let you know.

  4. #4
    Junior Member
    Join Date
    May 2012
    Posts
    32

    Default

    Hello Joecar.

    I ended up populating the table with 14.4 for stoich, LTFT's became more negative, not sure how I am meant to interpret this.

    Car feels more responsive and fuel economy has improved.

    Am I on the right track by populating table B3671 with this value.

    Thanks

  5. #5
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    14.4 might not be the right stoich AFR...

    yes.

  6. #6
    Junior Member
    Join Date
    May 2012
    Posts
    32

    Default

    Can you inform me what the correct stoich AFR is for Australian Premium 98 ron fuel.
    Thanks.

  7. #7
    Lifetime Member
    Join Date
    Aug 2013
    Posts
    735

    Default

    The correct stoich AFR is 14.7 for both regular unleaded and premium unleaded.

    The only difference between regular and premium unleaded is that premium unleaded has a higher RON number. The RON number is an indication of how resistant the fuel is to detonation. The higher RON number means that you can advance the spark timing more before you encounter engine knock.

    There's absolutely no benefit in using premium fuel unless your spark tables are tuned for premium fuel.

  8. #8
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    Premium being more knock resistant allows you to run more spark advance and/or higher compression ratio.

  9. #9
    Junior Member
    Join Date
    May 2012
    Posts
    32

    Default

    Thanks for the input fellas.

  10. #10
    Junior Member
    Join Date
    May 2012
    Posts
    32

    Default

    Hello joecar.
    I did not want to start another thread. Question is.

    In near the future I am going to fit some pacemaker long tube extractors and cat back exhaust.
    I know that I have to delete the two rear NB o2 sensors from the tune as there is no provision for them in the exhaust and I will only be using the NB o2 sensors fitted to each bank on the extractors.
    Now when I come to tune the VE table with a wideband do I need the information from both narrow band sensors? Or can I get away with unplugging one of them, plug my wide band in its place and tune the VE table from there?

    Thanks

Page 1 of 2 12 LastLast

Similar Threads

  1. Desired Airflow Question, not your normal question
    By Dale in forum General (Petrol, Gas, Ethanol)
    Replies: 25
    Last Post: October 1st, 2010, 10:10 AM
  2. Locked out timing question for boost setup question??
    By nitrorocket in forum General (Petrol, Gas, Ethanol)
    Replies: 13
    Last Post: September 13th, 2005, 02:22 PM

Posting Permissions

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