Turbo outlets: SPD vs AMS

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zombiekiller

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Get any size bucket you want to it doesn't matter. Get a bigger diameter hose to fill it then you will see how and what fills up faster.
you do realize that there is a lot more to turbo efficiency than " move more air through a bigger tube", correct?

for forced induction, in particular turbos, you need to pick up CFM AND velocity.

your example would only be picking up CFM.

The pump needs to create MORE pressure to maintain velocity when the "hose" gets larger. ( or you need a bigger pump)

If it doesn't, you'll actually lose power.

Most modern turbos need a specific backpressure target to maintain efficiency.
 

xrocket21

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you do realize that there is a lot more to turbo efficiency than " move more air through a bigger tube", correct?

for forced induction, in particular turbos, you need to pick up CFM AND velocity.

your example would only be picking up CFM.

The pump needs to create MORE pressure to maintain velocity when the "hose" gets larger. ( or you need a bigger pump)

If it doesn't, you'll actually lose power.

Most modern turbos need a specific backpressure target to maintain efficiency.

This is false. Turbo don't need backpressure, that's absolutely ridiculous. Exhaust headers use back pressure and scavenging to create more power. The best exhaust the hot side of a turbo is nothing. Anything else is a restriction.
 

Zeusmotorworks

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White papers on this from all over (both turbos and exhaust manufactures). NA engines don’t need “back pressure” either. They need proper velocity for efficient exhaust gas scavenging.
 

nikhsub1

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This is false. Turbo don't need backpressure, that's absolutely ridiculous. Exhaust headers use back pressure and scavenging to create more power. The best exhaust the hot side of a turbo is nothing. Anything else is a restriction.
Agreed. Centrifugal pumps never want or need back pressure. I will say that it is ALWAYS much worse to restrict the INLET of a centrifugal pump than to restrict the outlet.
 
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