Class 3 - gear ratios?

[PJTPW]

What is a typical axle gear ratio for a class 3 vehicle?

Also what is the top speed that this class would typically reach.

Thanks,

Ryan

[toddz]

What is a typical axle gear ratio for a class 3 vehicle?

Also what is the top speed that this class would typically reach.

Thanks,

Ryan

4.56-4.88's are typical.

Todd Z.

[01Baja4x4]

Are you talking about short wheel based SUV's? If so then 4.88 to somewhere in the 5's is common depending on the engine size. Top speed varies but I'd say rarely can they get over 80 just from the design of the courses.

-Tim

[roach]

you need to give more info...............tire size, auto or manual tranny, etc, etc.

[toddz]

4.56-4.88's are typical.

Todd Z.

I should add that my answer applies to my knowledge of the Broncos (Moss brothers, Chuck Atkinson, etc.).

Todd Z.

[PJTPW]

Yep, short SUV's.

35-37" tire.

I was guessing 4.56's with 35's and 4.88 with 37's, but wasn't sure if people ran the 5xx ratios or not.

TH400 for the transmission.

Wasn't sure if running the 5.xx gears would kill the top end, or with the limitations of the vehicles vs. the courses, would work out well due to lack of inherent speed.

Thanks for all the input. All this desert stuff is new to me.

Ryan

[TheWebWheeler]

I dont Race really but I would imagine it also depends on the course...
Short corse or Tight course that you wont be getting up to high speeds anyways then I would imagine You gear acordingly same with a wide open Long race course with high speed straights..

Well that how we'd do it in most other forms of racing..http://www.thewebwheeler.com/forums/images/smilies/shrug.gif

[Josh_K]

My truck is a class 8 but the drive train is the same as a decent to good 3 would have.

35" tires, 5.13 gears and a c6 give me just over a 100 mph on a graded road at about 6200 rpm.

Keep in mind that top end really isn’t that important in most cases. What is important is the ability to accelerate from a slow speed or a stop to about 50 or 60 mph. This is the magic speed to get to carry your truck over to rough spots.

Back when I was down on power (430hp) I used 5.67 gears and that work really well in places like Barstow. The top end was only about 90 but it accelerated decent (harder than a P.T. and 1k lbs heavier). I almost never used 1st. 70% of the time was in direct (3rd) and it worked well and 3rd is really strong. Now I have 575hp and can use a 5.13 and pulls it well.

Josh