Supercharger Information

There are three main categories of superchargers for automotive use:

 - Centrifugal turbochargers – driven from exhaust gases.
 - Centrifugal superchargers – driven directly by the engine via a belt-drive.
 - Positive displacement pumps – such as the Roots, Twin Screw (Lysholm), and TVS (Eaton) blowers.
Roots blowers tend to be 40–50% efficient at high boost levels. Centrifugal superchargers are 70–85% efficient. Lysholm-style blowers can be nearly as efficient as their centrifugal counterparts over a narrow range of load/speed/boost, for which the system must be specifically designed.

Positive-displacement superchargers may absorb as much as a third of the total crankshaft power of the engine, and, in many applications, are less efficient than turbochargers. Desirable in applications for which engine response and power are more important than any other consideration.

CFM of Blower
60 deg std - Cu in/rev = rotor length X 27.45
High-helix -  Cu in/rev = rotor length X 31.53

Opening Top:
15.06" x 4.43" W  (Buzzard and barn door)  14-71 (older)
12.25 x 4.00" W (bird and bug catcher)    6 to 10-71 (original)
11.875 "  x 4.50"
10.875 "     ( new style retro/setback etc)
10.50"  Top Fuel
10,00"  Top Fuel (max - 2019)
9.875 "       ( new style retro/setback etc)
9.500"
9,00
8.875"
10.00"
8,00"
7,00"
6,00"


Standard Blower Output - Cu. In. per Revolution   (5.840" represents modern designs)

SizeRotor Dia.Rotor LengthStandard Helix
Output     CI/Rev
High-Helix
Output
2-715.778 4.875136 
3-715.7787.482205-
4-715.7789.980274-
 5.840 290 
6-715.50514.975339 
 5.778 411472
 5.840 435 
8-715.77815.905436500
 5.840 461 
10-715.77817.000466536
 5.840 493 
12-715.77818.000494568
 5.840 522 
14-715.77819.000521600
 5.840 551 
16-715.77820.00--
 5.840 580580
18-715.77821.00--
 5.840 609609

 

 

Effective Compression Ratio Chart

Static
Compress.
Ratio
Blower Boost Pressure (psi)
 24681012141618202224
6.0:16.8:17.6:18.4:19.3:110.1:110.9:111.7:112.5:113.3:114.2:115.0:115.8:1
6.5:17.4:18.3:19.2:110.0:110.9:111.8:112.7:113.6:114.5:115.3:116.2:117.1:1
7.0:18.0:18.9:19.9:110.8:111.8:112.7:113.7:114.6:115.6:116.5:117.5:118.4:1
7.5:18.5:19.5:110.6:111.6:112.8:113.6:114.6:115.7:116.7:117.7:118.7:119.7:1
8.0:19.1:110.2:111.3:112.4:113.4:114.5:115.6:116.7:117.8:118.9:120.0:121.1:1
8.5:19.7:110.8:112.0:113.1:114.3:115.4:116.6:117.8:118.9:120.1:121.2:122.4:1
9.0:110.2:111.4:112.7:113.9:115.1:116.3:117.6:118.8:120.0:121.2:122.5:123.7:1
9.5:110.8:112.1:113.4:114.7:116.0:117.3118.5:119.8:121.1:122.4:123.7:125.0:1
10.0:111.4:112.7:114.1:115.4:116.8:118.2:119.5:120.9:122.2123.6:125.0:126.3:1
10.5:111.9:113.4:114.8:116.2:117.6:119.1:120.5:121.9:123.4124.8:126.2127.6:1
11.0:112.5:114.0:115.5:117.0:118.5:120.0:121.5:123.0:124.5126.0:127.5129.0:1


Lysholm Screw  Cu. In. per Revolution
 

PSI 200-A,C,H385
PSI 206-B422
PSI 210-C476
PSI 206-D422
Whipple A980601
Whipple R980601
Whipple 305R305

"Other " street / industrial

SizeRotor Dia.Rotor LengthOutput     CI/Rev 
"GMC" Straight 53 series (2 Lobe)
2-53  4.37570Bushings
3-53 6.5104"
4-53 Short 7.5120"
4-53 Long 8.7139"
"GMC" Straight 53 series (2 Lobe)
6-V53 Short 10.9174"
6-V53 Long 13.1209"
8-V53 15330"
"GMC" V 71 series (3 Lobe 30 deg)
6-V715.77812338Ball Bearings
8-V715.77815.9448"
Eaton (3 lobe 60 deg)
M-45 4.92145Ball/Needle bearing
M-62tall4.92162"
M-90 5.43390"
M-112tall5.386112"
B&M (3 lobe 60 deg)
144 8.7144Ball bearing
174  174"
250  250"
Weiand/Holley (2 Lobe Straight)
Pro 142 8.7142"
Pro 144 8.7144"
Pro 174  174"
Pro 177  177"
Pro 250  250"
Pro 256  256"
Camden
5 inch 580"
7 inch 7112"
9 inch 9144"
12 inch 12192"
S.Co.T Italmeccanica Italian (2 lobe straight cast rotor)
4500cc 8.7275"
4000cc 8.7275"
S.Co.T- H&H Flatheads/U.S.A (2 lobe straight billet rotor)
  8.7142"

Street Blower boost @ aprox 6000 RPM

OD RATIO %-25-20-15-10-505101520253035
              
6-71 std             
3508.29.611.112.614.115.617.118.620.121.623.124.626.1
4005.26.57.89.110.411.713.014.315.616.918.219.520.8
4542.73.85.06.17.38.59.610.811.913.114.215.416.3
5020.81.934.15.26.37.48.49.410.411.412.413.4
              
8-71 std             
35010.712.414.015.517.118.720.321.923.525.126.728.329.9
4007.69.010.311.713.214.616.017.318.720.121.522.924.3
45456.27.48.69.911.112.313.514.716.017.218.419.6
50234.25.36.47.58.69.710.812.013.114.215.316.4
5501.52.53.54.55.66.67.68.69.610.611.612.613.6
              
10-71 std             
4546.37.68.910.211.512.814.115.416.718.019.420.722.0
5024.35.46.67.89.010.211.412.513.714.916.117.318.5
5502.63.74.85.86.98.09.110.211.312.313.414.515.6
6001.22.23.14.15.16.17.18.19.110.111.112.113.1
650-0.91.82.73.64.55.46.37.38.29.110.010.9
              
12-71 std             
4547.58.910.311.713.114.515.917.218.620.021.422.824.2
5025.46.77.99.210.411.712.914.215.416.718.019.320.6
5503.64.85.97.18.29.410.511.712.814.015.116.217.3
6002.13.24.25.36.37.48.49.510.511.612.613.614.6
6500.81.82.83.74.75.76.67.68.69.610.511.412.3
              
14-71 std             
4548.810.311.713.214.716.117.619.120.522.023.525.026.4
5026.57.99.210.511.813.214.515.817.218.519.821.122.4
5504.75.97.18.39.510.712.013.214.415.616.818.019.2
6003.14.25.36.47.58.69.710.812.013.114.215.316.4
6501.72.73.84.85.86.87.98.99.910.912.013.014.0
              
14-71 HH