Results 1 to 4 of 4

Thread: E67 B4001 chart scale kPa values?

  1. #1
    Senior Member
    Join Date
    Jun 2012
    Posts
    147

    Default E67 B4001 chart scale kPa values?

    We are adding a turbo to an LE5 powered buggy. Siemens Deka 60lb injectors and 2 bar MAP. The car was previously tuned MAFless and operated for a couple years without issue. I read the tune and I am confused by the pressure scale in B4001. Instead of Vac MAP, it is Delta MAP 128 to 640. I am tempted to just scale it, but I would like to understand the units.
    Attached Files Attached Files
    05 GTO LS2 6spd E40, 70mm front mount turbo on stock long block

  2. #2
    Senior Member
    Join Date
    Jun 2012
    Posts
    147

    Default

    All my reference files were from 2006 vehicles. The donor for the buggy was a 2009 Solstice. I found a 2007 Sky that had the same table so my confidence has improved that this wasn't the result of previous tuning in another software. I am going to blunder ahead and re-scale the values despite not knowing precisely how this Delta MAP table works...
    05 GTO LS2 6spd E40, 70mm front mount turbo on stock long block

  3. #3
    Joe (Moderator) joecar's Avatar
    Join Date
    Apr 2003
    Posts
    28,403

    Default

    Rail pressure is 58 psi gauge (i.e. relative to barometric pressure)
    this is 400 kPa gauge (wrt baro),
    this corresponds to 500 kPa absolute (i.e. not relative to anything),
    so the absolute pressure at the top of an injector is 500 kPa.

    Now, at WOT, MAP is 100 kPa, this is the absolute pressure at the bottom of that injector,
    so at WOT, the pressure difference across that injector is 500 - 400 = 100 kPa.

    When throttle is snapped shut (from being open), MAP reaches as low as 20 kPa,
    so pressure difference across that injector is 500 - 20 = 480 kPa.


    so Delta MAP means pressure difference across any one injector.


    ( can you see how boost would cause pressure difference to go below 400 kPa...? )



    this portion of the new-style B4001 corresponds to 0-80 kPa in the old-style B4001 (LS1B):

    Delta MAP kPa Value
    400 3.567993
    416 3.639038
    432 3.706787
    448 3.773193
    464 3.848999
    480 3.890991

  4. #4
    Senior Member
    Join Date
    Jun 2012
    Posts
    147

    Default

    Thank you
    05 GTO LS2 6spd E40, 70mm front mount turbo on stock long block

Similar Threads

  1. 3Bar for 03 Suburban file, MAP scanner values are stuck at 105 kpa
    By gm22j in forum Custom Operating Systems
    Replies: 2
    Last Post: August 7th, 2017, 07:24 AM
  2. Replies: 20
    Last Post: January 17th, 2012, 12:48 AM
  3. Some PID's values don't fit in the chart...
    By joecar in forum General
    Replies: 6
    Last Post: March 17th, 2008, 04:00 PM
  4. DESIAC_B values and MAF values keep trimming down. Help!
    By ArKay99 in forum General (Petrol, Gas, Ethanol)
    Replies: 2
    Last Post: September 12th, 2005, 12:54 PM
  5. WOT MAP Values(kPa)
    By Black02SS in forum General (Petrol, Gas, Ethanol)
    Replies: 6
    Last Post: July 16th, 2005, 01:34 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
  •