top speed 4th gear

Discussion in 'SN95 4.6L Mustang Tech' started by WRXracer, Dec 12, 2003.

  1. ok what is the top speed with 410s and 430s in forth gear..

    how high do you rev..
  2. ok

    there has to be drag racers that know this..
  3. Ok, Im going to give you some gear calculations based a five speed transmission, the T-45. Theese gear calculations are also based with a 26in. tall tire w/ 4.10 gears.


    4th [email protected] = 109.422
    4th [email protected] = 111.308
    4th [email protected] = 113.195
    4th [email protected] = 115.081
    4th [email protected] = 116.968

    Here is a link to the site with the gear calculator is you wish to do more calculations.
  4. cool

    im getting 430 gears..
  5. My 4th is done at about 110-112 running it out the back door to redline.
  6. I've done 130+ several times in 4th gear......unfortunately I still have 3.27s. :(

  7. I calculate 113 mph w/ 4.10's, 26" effective tire diameter, and 6000 rpm. 4.30's would be 113 x 4.1/4.3 = 108mph.

    If your tire diameter is bigger, multiply whichever number (108 for 4.30's or 113 for 4.10's) by your tire diameter divided by 26. If you want a different engine speed, multiply by the new engine speed/6000.

    It is: speed = (rpms x diameter x 3.1416 x 60) /(rear ratio x 12 x 5280)

    or, more simply, speed = (rpms x dia.) / (336 x ratio)

    If you want to check it for other gears, just multiply the trans ratio by the rear ratio, and plug that total ratio into the formula.