Gearing Ratio Calculation

[Pep]

Hi all

Please help me

I need to know what rpm would my sierra do in 5th at 100kpm with Calmini 5.14 transfer gears

94 WT standard diffs on 30" Tyres

As i'd like to get these but do a fair bit of highway driving

Thaks Pep

[Gwagensteve]

use
http://www.novak-adapt.com/knowledge/gearing.htm

And the rock crawler gear ratios thread from Cj -

I get 3260 rpm, based on:

.76 overdrive, 1.67 high range, 3.7 diffs 30" tyres and 62 MPH road speed.

You might come up a bit higher than that if your rolling radius is less than 15", (which it will be) but I would have thought anything in the 3200-3800 range is workable on the highway.

Steve.

[Highway-Star]

use
http://www.novak-adapt.com/knowledge/gearing.htm

And the rock crawler gear ratios thread from Cj -

I get 3260 rpm, based on:

.76 overdrive, 1.67 high range, 3.7 diffs 30" tyres and 62 MPH road speed.

You might come up a bit higher than that if your rolling radius is less than 15", (which it will be) but I would have thought anything in the 3200-3800 range is workable on the highway.

Steve.

As Steve said, however the post 91' WTs have a slightly lower 5th gear. 0.86 I believe, whilst earlier models have the 0.79. This will make the revs a little more.

[Gwagensteve]

Thanks for the clarification Highway star -

hmmm based on a 29" actual tyre and .86 5th, RPM shoots up to 3817, which is what I would call the upper end of useable for extended cruising but not impossible- it's about what a stock Jimny is doing at 100.

Steve.