We're not an auto parts supplier and I can't respond to inquries for random Lexus and Toyota auto parts. All parts not listed above, including the LS400 and SC400 turbo kit, rebuild kits and supercharger are sold out and won't return.
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The table below was transferred from Corky Bell’s book Supercharged! ISBN # 0-8376-0168-1 Page 8
| Characteristic | Roots | Centrifugal | Screw |
| Low Speed boost capability | A | D | A |
| High boost – Pressure capability (10+ psi) | B | A | A |
| Fast boost rise | A | B | A |
| Thermal Efficiency | C | A | A |
| Volumetric Efficiency | B | B | A |
| Ease of Intercooling | C | A | C |
| Power Loss through supercharger | C | C | C |
| Simplicity of installation | B | A | B |
| Noise | C | C | C |
| Vibration | B | B | B |
| Space Requirement | C | B | C |
| Installation Convenience | C | B | C |
| Cost | B | A | C |
| Score | 2.69=B- | 3=B | 2.77=B- |
A= Excellent-4; B=Good-3; C=Fair-2; D=Poor-1
The final score is the total points divided by the total. I am getting the average of all the scores.
Root Score: 2.69 is B-
A-2 = 8
B-5 = 15
C-6 = 12
Centrifugal: 3.0 is B
A-5 = 20
B-5 = 15
C-2 = 4
Screw: 2.77 is B-
A-5 = 20
B-2 = 6
C-5 = 10
Here is another comparison of supercharger types:
| Type | Fix Displacement | Internal Compression ratio |
| Roots | Yes | No |
| Centrifugal | No | Yes |
| Screw | Yes | Yes |
Thermal Efficiencies of typical superchargers
| Type | Et (%) | Temp increase with 1 psi |
| Roots | 55 | 18.5 |
| Screw | 70 | 14.6 |
| Centrifugal | 75 | 13.6 |
| Turbocharger | 75 | ??? |