Intake Runner Length?

Discussion in 'PSI Superchargers Tech Questions' started by Bjs344, Aug 21, 2022.

  1. Bjs344

    Bjs344 Member

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    Does it matter on a roots blower motor?
     
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  2. MaggiFinn

    MaggiFinn New Member

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    I think there is so much violence below the blower that there is no chance for any waves or resonance, helping or hindering the intake charge based on runner length difference.

    I do believe however that it might be easier to distribute this violence between the runners by lifting the blower and having room to direct the runners where they could get fed with more fairness.

    But, life is full of compromises...
     
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  3. jay70cuda

    jay70cuda Well-Known Member

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    The only thing that matters is blower setback. That will make or break your combo.
     
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  4. Bjs344

    Bjs344 Member

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    I have this combo that won’t make power and got to thinking that the runners are super short compared to anything else out there. The blower is set back to the dash bar and the plugs come out even with minimal stagger (I think only a 2 spread across the motor).

    so nobody has ever found any power by adding runner length or plenum volume under a roots?
     
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  5. Mike Canter

    Mike Canter Top Dragster
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    The reason intake runner lengths are important are because of pulses on a normally aspirated motor. There are no pulses on a blower motor.
     
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  6. lucky devil

    lucky devil Member

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    I have seen a couple of Turbo Cars get hung up on this subject and spend a lot of time on manifold / runner design.
     
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