Thread: turbo or super
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Old 03-02-2021, 06:25 PM   #24
tomm.brz
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Quote:
Originally Posted by Irace86.2.0 View Post
You completely missed the context of the conversation. We were discussing the use of the bypass valve as a wastegate to bleed boost like turbos bleed exhaust, so someone could run a smaller pulley, but not hit high boost. Essentially they would bleed boost so boost would be flat instead of building with rpms. I was saying this means that if the supercharger is hitting 10 psi from 4-8k then it is spinning twice as much at 8k than at 4k while only producing 10 psi, so at 8k the engine is working harder creating more heat and is less efficient than it is at 4k. It is over-spinning while the bypass valve is open and bleeding/wasting boost. Turbos don’t waste boost, which is why they are much more efficient when doing boost-by-rpm/gear/map.
then it would just be easier to choke the inlet pipe with a restrictor.
It doesn't affect much under 5000 rpm but limits airflow capacity at high rpm

to reach a flatter boost curve like a PD supercharger or a turbo it would require such a small pulley that you ll overspin and break the impeller
Centrifugal sc anyway won't put out much boost at lower rpm even with a smaller pulley because it just won't spin enough

EDIT: and then after writing I remember that you actually don't have a centrifugal supercharger but the Harrop, sorry
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