What Gears Do I Need?

[jessedavis82]

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?

Thanks
Jesse D.

 

[SteedaGus]

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.

 

[08GTCSTurbo]

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

 

[Diode Dynamics]

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.

 

[F. Jason Garriott]

It could be worn shocks and non-sticky tires.

 

[Dugl]

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.

 

[timjimmy]

Is the car bucking under light throttle or just when you drop the hammer down? Manual or automatic?

 

[Bullitt347]

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.

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

 

[Husky44]

Gear swap isn't going to fix your problem, and may make it worse. You need to work on tightening up your rear suspension.

 

[Dugl]

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

 

[Dugl]

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.