My donation to this site.
I hope some of you will be able to put it to use.
OpenOffice required for the spreadsheet.http://www.openoffice.org/
This is a simulator I created to tell me the air flow, fuel flow, power and torque.
You give Atmospheric condition, eficiency of turbo, intercooler and engine...lambda and boost to use.
[you can view the results of modding these variable in the charts or in the model]
The simulator spits out everything else.
Its designed for 4 cylinder turbo diesel engines.
It wont be bang on....but should be pretty damn close.
For reference UK atmsopheric varies from 960-1060 mbar summer-winter and 30-0c air temps.
You should make sure your boost sits nice on the compressor map at all these extremes.
This should protect against surge, overspeed and choke in the UK.
Garrett uses 85f and 13.95psi absolute as correction for MAF readings to protect against surge.
86f(30c) and 13.92psi(960mbar) has even less air density than this and is a little safer.
Variables to Enter....Air Temp
[atmospheric temp to use for this simulation Farenheit]Air Pressure
[atmospheric pressure to use for this simulation psiA]Intercooler Pressure Loss Ratio
[assuming upto 3psi loss and peak MAP of 37 psi = 37/40]Induction Pressure Loss Ratio
[assuming upto 0.5psi loss and atmospheric is 14.5 = 14/14.5]No. Cylinders
[not used..only for 4 cylinder engines...adventurous could modify the the model using this to allow for more cylinders...I never got round to it]Displacement 2
[engine cc value here]Min RPM
[idle speed]Max RPM
[redline limit or map limit]Volumetric Efficiency Control
(descibes the ramp leading to the spike and slope after the spike).
Peak Volumetric Efficiency RPM [this is the rpm the VE spike occurs]
Start VE RPM [rpm you want to start the ve slope]
End VE RPM [rpm you want to end the ve slope]
Max VE% [this is the peak ve value where 1=100%]
Start VE% [the start ve value @ the start rpm]
End VE% [the end ve value @ the end rpm]
Volumetric Shape Start [not used]
Volumetric Shape End [not used]http://www.turbobygarrett.com/turbobyga ... elTech.pdf
If you datalog rpm iat map and maf you can use the formula in the pdf to calculate VE vs RPMCompressor Efficiency Control
(models the path the boost takes through the efficiency islands on the turbo compressor map).
Values as above...plus...
Volumetric Shape Start [The curve is cut into two part before and after peak. This is the curve before peak]
Volumetric Shape End [This is the curve after peak]
The values are an angle in degrees.
Based on a quarter circle that is cut by a chord to use less and less of the curve.
An angle of 0 used the whole 90 degrees of the curve (very fat and full).
A value of 89.999 uses only 0.001 degrees of the very top of the curve (more of a slope with curved end).
The two quarter circle segment join together at the peak and are always tangent to each other.Intercooler Efficiency control
(models the curve for the intercooler efficiency).
Values used as above.
You need to datlog your own car to work out you intercooler efficiency.http://www.not2fast.com/turbo/glossary/ ... tyCycle=85
This site will help you work out the efficiency.Lambda control
(lets you use a curve to define the AFR based on 14.6:1=lambda [editable]).
Values used as aboveStoichimetric ratio
(used for the Lambda calcs above...arguments exist over 14.5 or 14.6 so now you can change it).Brake Specific Fuel Consumption Control
(models the curve for BSFC in lb hp hr)
Values used as above
You need to hunt for your own values....datalog to work it out if needs must.
bhp x afr x (bsfc/60) = MAF lb/min ...use a dyno and measure MAF BHP RPM at the same time to work out BSFC vs rpm.
You know the AFR vs RPM....you entered it above and its in the model tab
Require the fuel to be calibrated correctly.Manifold Absolute Pressure Control
(models the boost curve you intend to use).
Values used as above.
you should keep an eye on the compressor map when adjusting.
Make sure you are not in surge, over revving or in choke at any Atmospheric temp or pressure.Variables & Charts displayed
(the model tab is a complete spreadsheet with all values that you can copy or reference into ECU table)
RPM vs VE%
RPM vs IE%
RPM vs CE%
RPM vs LAMBDA
RPM vs AFR
RPM vs MAP (mbar)
RPM vs MAP (psi)
RPM vs IAT (F)
RPM vs IAT (C)
RPM vs MAP (mbar)
RPM vs MAF (lb/min)
RPM vs MAF (g/s)
RPM vs MAF (mg/str)
RPM vs MFF (mg/str)
RPM vs TORQUE (NM)
RPM vs TORQUE (lf.ft)
RPM vs POWER (BHP)
RPM vs POWER (PS)
CURRENT BOOST ON COMPRESSOR MAP (uses the GT1752 tab for the compressor map limits..you should use your own turbos map)
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