What Gears Do I Need?

Discussion in '2005 - 2009 Specific Tech' started by jessedavis82, Jun 17, 2013.

  1. I just purchased a 2005 mustang gt, with a cold air intake, comp cams and longtube headers, also it's tuned if that matters. The car likes to bounce a lot coming out of 1st and the previous owner said the car would be better with different gears. What size gears should I run?

    Jesse D.
  2. Sounds like you are describing wheel hop. I would look at the rear suspension first and see if it still have the factory lower and upper control arms.
    Diode Dynamics likes this.
  3. depending on the cam you have you will need atleast 3.73 gears. the bigger cams will sacrifice driveability with the stock gear but going bigger will improve that
  4. It sounds more like a suspension issue than a gearing issue, wheel-hop is pretty common in the S197 if you're running mostly factory suspension components

    +1 on SteedaGus' answer

    Chassis stiffening is a good place to start IMO

    -Nick C.
  5. It could be worn shocks and non-sticky tires.
  6. Just word to the wise about my gear experience. I also have an 05 GT and opted for 4.10 gears, however afterwards I wanted fatter tires and lost a full inch on the diameter, which effectively gave me a 4.30 ratio....still love the acceleration, but plan your mods well.
  7. Is the car bucking under light throttle or just when you drop the hammer down? Manual or automatic?
  8. This could have easily been resolved by using one of the online tire size calculators. http://www.discounttire.com/dtcs/infoTireMath.dos This is an example of one such site. You could have found out that a 275/40/18 is within .59" in dia. of the stock 235/50/18 while gaining you 1.58" in section width. That usually works out to just over .8" of tread width per tire. This is another site that compares sizes http://www.tacomaworld.com/forum/tirecalc.php?tires=235-50r18-275-40r18
  9. Gear swap isn't going to fix your problem, and may make it worse. You need to work on tightening up your rear suspension.
  11. The problem was that my crystal ball saw lowering the car and not 18" wheels in my future. I will definitely think thrice about naturally aspirated vs fi when Cam shopping. Appreciate the sources u posted.