Question Truck won't keep up on the hwy

Discussion in '6.9 & 7.3L IDI Discussion (Non PowerStroke)' started by 94turbo5spd, Nov 23, 2018.

  1. 94turbo5spd

    94turbo5spd SDD Junior Member

    Messages:
    8
    Likes Received:
    0
    Joined:
    Nov 23, 2018
    Location:
    el campo tx
    I got a 94 2wd,5spd,7.3 turbo, f 450 with the 73 axle.its screaming at 70 mph on the hwy.what can I do to make it run lower rpm but increase the top speed?
     
  2. 01yellerCobra

    01yellerCobra Full Access Member

    Messages:
    335
    Likes Received:
    71
    Joined:
    Jul 18, 2015
    Location:
    San Diego
    Taller gears or taller tires are your only choices. What is the RPM?
     
  3. 94turbo5spd

    94turbo5spd SDD Junior Member

    Messages:
    8
    Likes Received:
    0
    Joined:
    Nov 23, 2018
    Location:
    el campo tx
    At 70mph,a little over or around 3000rpm,but dont need to go any faster than 75.would a complete rearend swap be a option?or easiest?
     
  4. 94turbo5spd

    94turbo5spd SDD Junior Member

    Messages:
    8
    Likes Received:
    0
    Joined:
    Nov 23, 2018
    Location:
    el campo tx
    What size taller gears?and would I be able to swap rims and tires with a newer model
     
  5. 01yellerCobra

    01yellerCobra Full Access Member

    Messages:
    335
    Likes Received:
    71
    Joined:
    Jul 18, 2015
    Location:
    San Diego
    I would think swapping gears would be easiest. It might be worth talking to a local 4x4 shop. They should be really good at swapping gears and could give you an idea what would be the easiest route.
     
  6. snicklas

    snicklas Super Moderator Staff Member

    Age:
    44
    Messages:
    399
    Likes Received:
    21
    Joined:
    Aug 10, 2008
    Location:
    Greenfield, Indiana
    Welcome!

    Since this is an IDI, I would recommend to go to our sister site:

    www.oilburners.net

    The 6.9 and 7.3 IDI section is about the best forum for these trucks.

    However, with the being the F-Superduty, the highest gear is going to be 4.88:1, but more than likely 5.13:1 or lower. The F-Superduty (450) is geared this way for GVW. That speed limit is about what you would expect for one of those trucks. They will run pinned to the governor all day and be just fine. But it's not going to be a speed deamon..... Your biggest limiting factor is the Dana 80.

    Once you are on oilburners, search on user towcat and F-Superduty or F-450. He ran them for years, unfortunately he passed unexpectedly a couple weeks ago.
     
  7. 94turbo5spd

    94turbo5spd SDD Junior Member

    Messages:
    8
    Likes Received:
    0
    Joined:
    Nov 23, 2018
    Location:
    el campo tx
    Thank you guys for the help!
     

Share This Page