[MrRocky]

just assesing my gearing options on my new sierra, i have a tcase with 6:5 gears in and 2 sets of 4.1 diff gears, which one should i use to aim for 3600-3800 rpm at 110 km/phr in 5th as i need to be sitting on 110kms for a few longer trips away this year.

cheers mick

[alien]

you'd want standard 3.7 WT diffs, as the 3.7-4.1 is a 12% reduction, and the 6.5's are a 20% reduction on high range.

a 31 is 19.2% larger than a factory 26" tyre, so 6.5 and WT diffs would be just lower than factory gearing.

Even then though you'd need 5.14 gears to achieve the lower RPMs for 110km/hr... i think mine sits around 3500rpm at 110km/hr

[MrRocky]

ok so 6:5's it is then

[birko]

Yep, thats about my revs with 3.7's and 6.5 tc gears.

[Built4thrashing]

Whats 110kms? sierra's only go that fast when on a trailer.

[alien]

dunno about that, was doig 120 in mine just yesterday =P

[zooky08]

130 in mine along a straight

[5ierra]

alien wrote:

you'd want standard 3.7 WT diffs, as the 3.7-4.1 is a 12% reduction, and the 6.5's are a 20% reduction on high range.

a 31 is 19.2% larger than a factory 26" tyre, so 6.5 and WT diffs would be just lower than factory gearing.

Even then though you'd need 5.14 gears to achieve the lower RPMs for 110km/hr... i think mine sits around 3500rpm at 110km/hr

My 1.6 Sierra revs at 3800 - 4000 @ 100 or so with 6.5's, 31's and 3.7's

[neofitou]

Mines about 4100rpm at 110, and at 5500rpm its much faster.
I have 31s, 6.5s and 3.9s, and no weight in the car.

[mighty_vites]

zooky08 wrote:

130 in mine along a straight

if you put a spoiler on it i rekon you could get airborne at that speed, chitty chitty bang bang has nothin on a flying zook

[crewsy]

mine does about 3850 @ 110 with 6.5's + 3.7's + 32's