Originally Posted by
joecar
To calculate what the VSS should read at any RPM, create a calculated pid using this equation...
vss = rpm x tire_diameter / (trans_ratio x axle_ratio x factor)
Here's my calc_pids.txt file...
Code:
# ==============================================================================
# File details
# ------------
#
# This section defines various details about the file format.
*FILE
#Parameter Value Description
#---------- ---------------- ---------------------------------------------------
VERSION 7.1.1 File version
DECSEP . Decimal separator used in this file
# ==============================================================================
# Units
# -------------------
# See sae_generic.txt for more information on the *UNITS section
*UNITS
#Code System Abbr Description
#-------- ---------- -------- -------------------------------------------------------------
None None "" "No units"
# ==============================================================================
# Add slot definitions here
# --------------------------------
# See sae_generic.txt for more information on "SLOT" formats
#
#Units Low High Fmt Expression
#------------ ------------- ------------- ---- --------------------------------------------------------------
*CLC-00-060
mph 0.0 160.0 .0 "{SAE.RPM} * 25.66 / ({GM.BOXRATIO} * 3.23 * 336.135)"
kph 0.0 260.0 .0 "{SAE.RPM} * 651.8 / ({GM.BOXRATIO} * 3.23 * 5305.16)"
# ==============================================================================
*PRN - Parameter Reference Numbers
# --------------------------------
# See sae_generic.txt for more information on the *PRN section
#
#Code PRN SLOT Units System Description
#------------------------- ---- ------------ ---------------- ---------------- ------------------------------------------
CALC.VSS F060 CLC-00-060 "mph,kph" Calculated "Calculated VSS"
My car has tire diameter is 25.66" (651.8mm) and 3.23 rear.