Rear gear question? Blown Top Dragster.

Discussion in 'PSI Superchargers Tech Questions' started by slegermotorsports, Jul 14, 2015.

  1. slegermotorsports

    slegermotorsports New Member

    Joined:
    Dec 1, 2010
    Messages:
    19
    Likes Received:
    0
    Hi guys, We run a Top Dragster that we are wondering what some guys with similar sets up are running for rear end gear ratios?

    Here is a little on our set up: 250" swing arm dragster, 17x34.5 Hoosier tires, currently 4.11 gears, power glide trans 1.80 first gear. Engine is a 540 Chevy with a SSI 1471, 30# boost. Cars weighs 2150 with driver. We run 6.3s at 218mph with no tire shake at all. 1.00 sixties.

    Our concern is through the top end as were turning 8400 with the dragster shifting at 8400-8500. This is higher than we want to be. Ideally looking to trap at 7800-8000. Do we switch and try 3.89 gears or drop it all the way to a 3.70 gear? Are we going to kill the car off the line with a 3.70? Just looking for some input and what others may be using.... Thanks
     
    #1
    slegermotorsports, Jul 14, 2015
  2. caseyspradlin

    caseyspradlin Member

    Joined:
    Sep 9, 2008
    Messages:
    214
    Likes Received:
    0
    3.89

    Exact same setup. 3.89 gears. Shift 7600 cross 7800. Retard launch timing to have 1 flat leaving at 4200. No shake. Hoosiers from racing tires by Jody way to go.
     
    #2
    caseyspradlin, Jul 15, 2015
  3. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
    Staff Member

    Joined:
    May 6, 2003
    Messages:
    6,706
    Likes Received:
    133
    rpm

    Is there a reason why you are wanting to lower the rpm? Are you experiencing any parts failures or feel like you are going to have to service it sooner than you want?

    Just saying TD is getting quicker and quicker. Also sometimes lugging the motor is just as hard as freeing it up with a little more rpm.
     
    #3
    Will Hanna, Jul 15, 2015

Share This Page





XenPorta 2 PRO © Jason Axelrod from 8WAYRUN.COM