Results 1 to 4 of 4

Thread: Previous tune using IFR for smaller injectors than fitted

  1. #1
    Lifetime Member
    Join Date
    May 2007
    Posts
    254

    Default Previous tune using IFR for smaller injectors than fitted

    Guys

    just been working through upgrading my tune. The OS had actually been changed from the original 2001 GM OS to an earlier 99 OS then had a tune applied. I'm confident in the work that was done but have a question.

    The IFR on my tune was set for the smaller injectors fitted to earlier LS1s.

    I then upgraded to the custom OS3 and applied the HSV 04 Clubsport tune. Below is the different IFR tables, the before is obviously from the tune that was previously applied.

    My question is how exactly will the previous table been possibly effecting the car?

    before
    kPa Injector Flow Rate (Grams/Second)
    0 3.296875
    5 3.351563
    10 3.421875
    15 3.601563
    20 3.648438
    25 3.703125
    30 3.750000
    35 3.773438
    40 3.796875
    45 3.828125
    50 3.851563
    55 3.882813
    60 3.921875
    65 3.953125
    70 4.000000
    75 4.046875
    80 4.101563

    after

    kPa Injector Flow Rate (Grams/Second)
    0 3.546875
    5 3.601563
    10 3.679688
    15 3.875000
    20 3.921875
    25 3.984375
    30 4.031250
    35 4.054688
    40 4.078125
    45 4.117188
    50 4.140625
    55 4.187500
    60 4.257813
    65 4.328125
    70 4.421875
    75 4.523438
    80 4.632813

  2. #2
    Lifetime Member eboggs_jkvl's Avatar
    Join Date
    Apr 2004
    Posts
    757

    Default

    The question is....

    What size injectors are you running now? Set for those in your IFR and then start your tune.

    Injector size:
    99 ~26.4 lb
    01 ~28.8 lb


    Elmer

  3. #3
    EFILive Distributor dfe1's Avatar
    Join Date
    Jan 2005
    Posts
    837

    Default

    If you're trying to correlate what is to what was to what should be-- IFR data that is lower than ACTUAL injector flow will cause AFR to be richer than it should be, if IFR is higher than actual, AFR will be leaner. The PCM calculates injector pulse width based on IFR relative to operating conditions (rpm, MAP, MAF or both and whatever other modifiers come into play). Obviously, you don't have to keep a 4.5-gram injector open as long as a 4-gram model to discharge the same amount of fuel-- and vice versa. Of course, if the VE table has been altered to compensate for the difference in injector flow, correcting IFR will require redoing the VE table.
    DigitalEFI- EFILive US Distributor
    sales@digitalefi.com
    678/344-1590

  4. #4
    Lifetime Member
    Join Date
    May 2007
    Posts
    254

    Default

    elmer the car is a 2004 Monaro so should be 28.8

    I beleive that when running with maf/o2's it should take care of things

    I've currently got this tune applied, the VE table is using that from the HSV tune as currently have no widebands installed.

    http://www.stigmundfreud.f2s.com/tuning/upgraded.tun

Similar Threads

  1. best injectors to tune
    By pdasterly in forum Gen IV V8 Specific
    Replies: 2
    Last Post: December 9th, 2009, 03:24 PM
  2. What to tune with red top svo injectors?
    By dirt_track_racer_81 in forum General (Petrol, Gas, Ethanol)
    Replies: 29
    Last Post: December 4th, 2006, 10:11 AM
  3. Restoring Previous OS ?
    By DrX in forum General (Petrol, Gas, Ethanol)
    Replies: 7
    Last Post: November 19th, 2005, 04:19 PM
  4. How To Tune For Larger Injectors
    By RacerChris in forum General (Petrol, Gas, Ethanol)
    Replies: 8
    Last Post: November 9th, 2005, 01:20 PM
  5. Previous tune with LS1Edit
    By ibjamin in forum General (Petrol, Gas, Ethanol)
    Replies: 1
    Last Post: January 15th, 2005, 10:39 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
  •