Tuning Port and Hat Nozzles

Discussion in 'PSI Superchargers Tech Questions' started by wagspe208, Jun 14, 2011.

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  1. Mike Canter

    Mike Canter Top Dragster
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    The answer to your question is no the idle EGTs do not matter that much as long as they all fall within a range. The only danger is of being too cold on a cylinder at idle is that since you launch from idle you could do what we call "put the fire out" in that cylinder and it will take too long to recover and you will be down on power. The hat nozzles are not going to balance your cylinders at idle because all that fuel is being mixed up in the rotors and go out the bottom at a foward angle. If that is your EGT spread from 250 to 436 then the setup is close at idle. I would lean out the BV to bring that cold cylinder up to around 400* to keep it going. It is not uncommon to have the back cylinders up around 500-550 when all the others are at 400-450. You just can't balance the cylinders at idle unless you run dribblers which you do not want to do. So just adjust the BV a little leaner and all will be good.

    Why the open bottom on a High Helix? You are losing a lot of boost and defeating the reason for a HH?
     
    #21
    Mike Canter, Jun 21, 2011
  2. wagspe208

    wagspe208 Member

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    Gotcha... that is the answer I wanted Mike.
    Open bottom (mostly).
    1) I did not want tuneup to change a huge amount. (it did not)
    2) We run about 13# of boost to run the 8.0 class. It only takes 20# ish to run the 6.0 @ 1000' class.
    3) I mostly bought the blower cause it looks cool IMO. And my old gas mooneyham would max out at close to 20 ish, so if horrible air came by I would fall a little short on power.
    4) 10-71.. did not want to mess with offset drive/ front mount dist, etc with the offset of a retro opening. I could have bought many used 14-71's more than adequit for us... see #1, #3, and #4.
    5) Oh, I think Eric was runnning 10 HH rotors when I ordered it.
    6) Most importantly. High helix is fun to say.

    Oh, my old gas blower on would take 8% over to run the 8.0 in x air. The new piece makes the power at 4% underdriven. (same air)
    Low hp application.
    Thanks again.
    Wags
     
    #22
    Last edited: Jun 21, 2011
    wagspe208, Jun 21, 2011
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