Roots max rpm

Discussion in 'PSI Superchargers Tech Questions' started by racecar1517, Aug 7, 2017.

  1. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    Boost/Flow seems to be the most common number thrown around, so I was specifically addressing that.
     
    #21
  2. Mike Canter

    Mike Canter Top Dragster
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    I wouldn't call that a AFR compution. That's just a number that happens to fall within the same approximate numbers as AFR. Ok to use it, call it a guide number but not AFR
     
    #22
    Last edited: Aug 20, 2017
  3. 68cudab1

    68cudab1 Member

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    Could you please share the more accurate AFR computations?
     
    #23
  4. Mike Canter

    Mike Canter Top Dragster
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    Sorry can't do that. Too much time and effort in developing it.
     
    #24
  5. aj481x

    aj481x Member

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    Secret stuff :cool:
     
    #25
  6. Nasa6173

    Nasa6173 New Member

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    Mike, can you enlighten me on which ways are considered accurate and inaccurate?

    I know my way has variables I have yet to find a way to accurately calculate
     
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  7. bob szabo

    bob szabo FC / altered

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    Just to qualify: I was not saying to jet and engine for 6.45 to 1 AFR. I was saying how it works. Fuel enrichment is done to keep cylinder temperature below the self ignition temperature of the fuel. For methanol, that is in the vacinity of 800 deg. F. Pre-ignition occurs anytime any part of the cylinder contents exceed the self ignition temperature before spark ignition. The extra fuel retards pre-ignition before the planned flame front from the spark plug. All that burns though is 6.45 to 1. After peak combustion, ideally at 2 degrees after TDC, all of the extra fuel is in the way and reduced power. That is why the amount of enrichment is so critical to making the max performance.
     
    #27
  8. Mike Canter

    Mike Canter Top Dragster
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    Thanks Bob, just didn't want anyone misunderstanding you and try and lean the motor out to that real AFR
     
    #28
  9. racecar1517

    racecar1517 Member

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    A huge thank you to Mike, Bob and as always Will.

    As I asked questions and watched the thread evolve I suspected that boost to flow ratio would be another guide more than a tool to the pursuit of quicker et's.

    It's hard work to haul ass!
     
    #29

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