Rear end gears

Discussion in 'PSI Superchargers Tech Questions' started by hydrotherapy, Jan 17, 2017.

  1. hydrotherapy

    hydrotherapy Member

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    I have a alter that weighs 2350 with a brad 540ci 4.375 x 4.5 cr 12 to 1 cr brad 5 heads, k11 superman with all mod done DMPE,Lencodrive three speed,1.31 and a 1.28 ratio Neal chance nsx converter,36 goodyears tires .
    Class rules no electronics no two steps 20% on blower all timing changes and shifts can be made by driver
    What rear end gear should I run? Can run as fast as 6.0 or as fast as the conditions will allow
     
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  2. Mike Canter

    Mike Canter Top Dragster
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    My bet will be a 4.29 or a 4.56 depending what rpm you want to push it to at the finish line. With 36" tires and a 1.67 first gear you may need a 4.56 but you should be light.
     
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  3. hydrotherapy

    hydrotherapy Member

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    Thanks Mike
    I thought that would be the answer ,but I needed someone else to say that,Right now we have a 390 gear in it and I knew that wasn't enough,but still needed someone else option.
    Thanks again
     
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  4. Mike Canter

    Mike Canter Top Dragster
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    The problem with 3.90 gears is that the motor may flatline in high gear. How much engine rpm drop do you see when you shift to second gear?
     
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