3.00 gears and RPM's

Discussion in 'Technical' started by rebelgt, Jun 24, 2007.

  1. rebelgt

    rebelgt Member

    Joined:
    Mar 10, 2007
    Messages:
    45
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    Southeast Missouri
    Vehicle:
    1972 Comet GT
    what kind of RPM's should I expect from a 302 with c-4 and 3.00 gears at 55 or 60 mph?
     
    rebelgt, Jun 24, 2007
    #1
  2. T.L.

    T.L. Banned

    Joined:
    Oct 5, 2002
    Messages:
    4,187
    Likes Received:
    3
    Trophy Points:
    0
    Location:
    Southern Colorado
    Vehicle:
    '73 Maverick 2-door, V-8
    Around 2600 RPM @ 60mph...
     
    T.L., Jun 24, 2007
    #2
  3. Mavaholic

    Mavaholic Growing older but not up!

    Joined:
    Mar 9, 2002
    Messages:
    14,992
    Likes Received:
    209
    Trophy Points:
    258
    Location:
    Live Oak, FL
    Vehicle:
    Original 72 Sprint Owner, 71 Comet GT, 57 Ranchwagon, 57 4 dr Wagon
    What size tire are you running?
     
    Mavaholic, Jun 24, 2007
    #3
  4. T.L.

    T.L. Banned

    Joined:
    Oct 5, 2002
    Messages:
    4,187
    Likes Received:
    3
    Trophy Points:
    0
    Location:
    Southern Colorado
    Vehicle:
    '73 Maverick 2-door, V-8
    The tire diameter does affect it, but ever so slightly (unless you're running 28-inch tall tires Vs. 25-inch)...
     
    T.L., Jun 24, 2007
    #4
  5. Max Power

    Max Power Vintage Ford Mafia

    Joined:
    Aug 7, 2002
    Messages:
    1,230
    Likes Received:
    1
    Trophy Points:
    0
    Location:
    St. Paul, MN
    Vehicle:
    1977 Maverick, 1969 Mustang Sportsroof, 1970 Mustang Grande Project
    There are gear rpm calculators all over the web. Google it up.
     
    Max Power, Jun 24, 2007
    #5
  6. Hawkco

    Hawkco Genuine Car Nut

    Joined:
    Jan 2, 2004
    Messages:
    5,281
    Likes Received:
    10
    Trophy Points:
    135
    Location:
    Rex, Georgia (GA)
    Vehicle:
    77 Maverick
    26 inch tall tire + 3.00 gear + 2,325 RPM = 60 MPH.
     
    Hawkco, Jun 24, 2007
    #6
  7. 71 Comet

    71 Comet Member

    Joined:
    Nov 11, 2005
    Messages:
    16
    Likes Received:
    0
    Trophy Points:
    33
    Location:
    London Ontario Canada
    Vehicle:
    1971 Comet
    RPM= MPH X Final Drive Ratio Tire O.D. (inches) X 0.002975
     
    71 Comet, Jul 17, 2007
    #7
  8. 71 Comet

    71 Comet Member

    Joined:
    Nov 11, 2005
    Messages:
    16
    Likes Received:
    0
    Trophy Points:
    33
    Location:
    London Ontario Canada
    Vehicle:
    1971 Comet
    The post above did not print as I had typed it. I'll try again. RPM=(MPH x Final Drive Ratio) divided by (Tire O.D. in inches x 0.002975)
     
    71 Comet, Jul 17, 2007
    #8
  9. T.L.

    T.L. Banned

    Joined:
    Oct 5, 2002
    Messages:
    4,187
    Likes Received:
    3
    Trophy Points:
    0
    Location:
    Southern Colorado
    Vehicle:
    '73 Maverick 2-door, V-8
    That sounds pretty close. I think my RPMs increased by about 500 when I switched from 3.00 to 3.55 ...
     
    T.L., Jul 17, 2007
    #9

Share This Page