Thread: The SR20 Pressure Ratio/Air Flow Rates w/ 85% Ev

Here it is in Pic Format





Here it is in Text format.
More expanded version of above
This enables you to quickly plot multiple boost pressures against varios rpm points
Details Figures
Turbo adiabatic efficiency % 75
Air inlet temp ('deg f) 70
Atmospheric presure 14.17 (14.7 is Sea Level) Corrected elevation For Roanoke Va @ 1100 feet
Displacement (Ci) 121.878
Number of Turbos 1


Answers:

Ev% (Vol Eff) 85.00 85.00 85.00 85.00 85.00 85.00 85.00 85.00 85.00 85.00 85.00 85.00
rpm -------------2,000 - 2,500 - 3,000 - 3,500 - 4,000 - 4,500- 5,000 - 5,500 - 6,000 - 6,500 - 7,000 - 7,500

Boost -----PR -----------Inlet Air Flow (CFM)
01 -1.070571630 062.55 078.19 093.83 109.47 125.10 140.74 156.38 172.02 187.65 203.29 218.93 234.57
08 -1.564573042 079.44 099.30 119.16 139.02 158.88 178.74 198.60 218.46 238.32 258.18 278.04 297.90
10 -1.705716302 083.93 104.92 125.90 146.88 167.87 188.85 209.84 230.82 251.80 272.79 293.77 314.75
14 -1.988002823 092.58 115.73 138.87 162.02 185.17 208.31 231.46 254.60 277.75 300.90 324.04 347.19
16 -2.129146083 096.76 120.95 145.14 169.33 193.52 217.71 241.90 266.09 290.28 314.47 338.66 362.85
20 -2.411432604 104.86 131.08 157.29 183.51 209.72 235.94 262.15 288.37 314.58 340.80 367.01 393.23

Inlet Air Flow (lbs/min)
Boost 2,000 2,500 3,000 3,500 4,000 4,500 5,000 5,500 6,000 6,500 7,000 7,500
01 1.07057163 4.32 5.40 6.47 7.55 8.63 9.71 10.79 11.87 12.95 14.03 15.11 16.19
08 1.564573042 5.48 6.85 8.22 9.59 10.96 12.33 13.70 15.07 16.44 17.81 19.18 20.56
10 1.705716302 5.79 7.24 8.69 10.14 11.58 13.03 14.48 15.93 17.37 18.82 20.27 21.72
14 1.988002823 6.39 7.99 9.58 11.18 12.78 14.37 15.97 17.57 19.16 20.76 22.36 23.96
16 2.129146083 6.68 8.35 10.01 11.68 13.35 15.02 16.69 18.36 20.03 21.70 23.37 25.04
20 2.411432604 7.24 9.04 10.85 12.66 14.47 16.28 18.09 19.90 21.71 23.52 25.32 27.13

Kg/s
Boost 2,000 2,500 3,000 3,500 4,000 4,500 5,000 5,500 6,000 6,500 7,000 7,500
01 1.07057163 0.0346 0.0432 0.0518 0.0605 0.0691 0.0778 0.0864 0.0950 0.1037 0.1123 0.1210 0.1296
08 1.564573042 0.0439 0.0549 0.0658 0.0768 0.0878 0.0988 0.1097 0.1207 0.1317 0.1426 0.1536 0.1646
10 1.705716302 0.0464 0.0580 0.0696 0.0812 0.0927 0.1043 0.1159 0.1275 0.1391 0.1507 0.1623 0.1739
14 1.988002823 0.0512 0.0639 0.0767 0.0895 0.1023 0.1151 0.1279 0.1407 0.1535 0.1662 0.1790 0.1918
16 2.129146083 0.0535 0.0668 0.0802 0.0936 0.1069 0.1203 0.1336 0.1470 0.1604 0.1737 0.1871 0.2005
20 2.411432604 0.0579 0.0724 0.0869 0.1014 0.1159 0.1304 0.1448 0.1593 0.1738 0.1883 0.2028 0.2173

cfm 59.95 74.94 89.93 104.92 119.90 134.89 149.88 164.87 179.85 194.84 209.83 224.82 <<-- This should be the Airflow w/o boost.


Boost p2= t2= outlet temp 'F temp rise in F adiabatic temp Rise Actual outlet Temp F Density Ratio
01 15.17 540.3644096 80.36440963 10.36440963 13.81921284 83.81921284 1.043366896
08 22.17 601.8444902 141.8444902 71.8444902 95.7926536 165.7926536 1.325077416
10 24.17 616.7901093 156.7901093 86.79010929 115.7201457 185.7201457 1.400033197
14 28.17 644.2082714 184.2082714 114.2082714 152.2776951 222.2776951 1.544300075
16 30.17 656.8802739 196.8802739 126.8802739 169.1736986 239.1736986 1.613972932
20 34.17 680.5217437 220.5217437 150.5217437 200.6956582 270.6956582 1.749099322



I have this in excel Format if needed.

Just to make it look better i also included Pic format. Also if you want this is your corrected Elevation let me know and I will happily do so.

Aslo I will be willing to Plot this info on Compressor maps if people would like to see them.

Anyone know the Voltrametric Effiency of an SR20?

post up the excel file

as far as the VE goes, i've used anything in the 90s% How exactly do you determine the VE of an engine?

Garrett says to use anywhere from 95-99 percent for 4 valve heads for turbo... to be conservative I used 95 in some calcs I was doing when I was learning off their site to be conservative.

IIRC, in one of the articles for NPM, Mike K. used 85% for the DE.