overdrive change on tune up k11

Discussion in 'PSI Superchargers Tech Questions' started by FORDMAN, Mar 9, 2009.

  1. FORDMAN

    FORDMAN New Member

    Joined:
    Dec 14, 2008
    Messages:
    11
    Likes Received:
    0
    How much more boost (or gpm of fuel) do you think a 1471 littlefield, with k11 rotors would make going from 22 over to 28 over on a 548 wedge shifting at 7000rpm. Right now it’s close to 25psi at 22over. I was thinking of adding .4 of a gallon to the tune up?


    I’ve read that there is a “point” where these things really come alive. Is there truth to that statement, or is the boost/power gains at this level pretty linear?


    Does the k11 start to like 10k, or is it , just doesnt fall off like other rotors at higher rpms
    :confused::confused::confused:
     
    #1
    FORDMAN, Mar 9, 2009
  2. aj481x

    aj481x Member

    Joined:
    Jan 27, 2004
    Messages:
    976
    Likes Received:
    18
    That would probably be a good starting place. The increase is no where near linear as the "law of diminishing returns" really applies to a roots.
     
    #2
    aj481x, Mar 10, 2009
  3. Mike Canter

    Mike Canter Top Dragster
    Staff Member

    Joined:
    Mar 10, 2004
    Messages:
    4,630
    Likes Received:
    189
    Yes, there is a point where things come alive. The question is if you want to go there with your motor. With shifting at 7000 rpm you are not going to see the big gains in boost that are just waiting for you. By just going to 8000 RPm you should see a lot more boost. The K-11 is a great blower and it is routinely run at over 50% OD making tons of boost at over 9000 RPM on the motor. You have some way to go before you have to worry about diminishing returns. Some blowers at the 20-22% OD can give you a 4-5 lbs boost increase from going from 7000 to 8000 RPM. If you don't want to crank up the RPM that much then I would bring the OD up some. If you always use the same RPM in third gear for measuring boost. Such as always at 7000 RPM or always at 8000 RPM and for every one pound increase of boost you see at this reference RPM then add .3 to .4 GPM to you tuneup you should be safe. Do you have a data logger with EGTs?
     
    #3
    Mike Canter, Mar 10, 2009

Share This Page





XenPorta 2 PRO © Jason Axelrod from 8WAYRUN.COM