3.45 or 3.7 diff gears into my 5spd VS S?

[5spdVS]

Hey guys, I'm interested in buying some new diff gears but wasnt too sure whether to go 3.45's or 3.7's.

Would love to hear some opinions/recommendations.
Thanks!

[Commydoor]

horses for courses...my diff guy recommended the 3.7's as a good all rounder...better acceleration but still economical...i went 3.9's fark the economy...

[Claudy]

I put 3.45s in my vt with t5 behind it and at 100km/h it sits bout 2150-2200rpm better acceleration than standard 3.08s. Was gonna go 3.7s but i drive 100kms a day on freeway so didn't want it revin too high...

[RX25SE]

Hey guys, I'm interested in buying some new diff gears but wasnt too sure whether to go 3.45's or 3.7's.

Would love to hear some opinions/recommendations.
Thanks!

V6 or V8???

[bpefi]

I have a 93 Hilux dualcab with a vs engine & 3.7 diff ratio & its fine getting 12-13 on highway great acceleration..

[RX25SE]

I have a 93 Hilux dualcab with a vs engine & 3.7 diff ratio & its fine getting 12-13 on highway great acceleration..

What size are the tyres?

This has a large effect on the overall gearing.

[bpefi]

What size are the tyres?

This has a large effect on the overall gearing.

215/70r15 before now 225/50r16

[thetriksta99]

go 3.9s with a 5 speed, this is what i have in my auto and they are awesome. #### economy, if you want economy go buy a smart car or hybrid. make sure you get new 3.9's not second hand 3.89's out of the nissans cause they are noisy even when new, alot of guys on ebay sell these cheap and advertise them as 3.9's.

[vs commo]

Is it true that to put 3.7s in my vs v6 u can use them from an r31 skyline or do u need to buy them new???sorry for hijackn lol

[bpefi]

Not sure - there is other treads on this - do a search

[Super_Low 91]

if you can find some in decent condition then by all means go for it

[bpefi]

I originally had 4.3 ratio diff gears - still got reasonable economy - revved a bit on highway though

[5spdVS]

Sorry for the late reply guys. Yeh I have been doing my research and have been looking for a good set of 3.7's but havent had any luck.
Was gonna finish some last mods then sell her so i could buy a VR SS or VS SS. Really want to spend my money on a v8. Thanks for all your posts though!

[[p]wrr-247]

im keen on getting some 3.7s in my lsd v6 ecotec whats the rev range sitting on the highway because gotta use it for work cheers

[immortality]

im keen on getting some 3.7s in my lsd v6 ecotec whats the rev range sitting on the highway because gotta use it for work cheers

assuming auto trans? (0.70:1 OD) assuming 17" wheels about 2150rpm

I put 3.45s in my vt with t5 behind it and at 100km/h it sits bout 2150-2200rpm better acceleration than standard 3.08s. Was gonna go 3.7s but i drive 100kms a day on freeway so didn't want it revin too high...

VT has the getrag 260 gearbox which has a final drive ratio of 0.81:1 (instead of 0.72 of the T5) which then works out about right for 2150rpm with only 3.45 gears in the ass

[[p]wrr-247]

lol good guess auto and 17s cant remember what the revs were sitting on when i went up the coast but 2150 dont seem to bad am i wrong what does it sit on stock

[immortality]

lol good guess auto and 17s cant remember what the revs were sitting on when i went up the coast but 2150 dont seem to bad am i wrong what does it sit on stock

LOL, my spread sheet is set up with the figures for a 17" rim with 235/45 profile tyres

stock with 17's it should be just under 1800rpm @ 100km/h.

[[p]wrr-247]

yer thats not to bad thanks for that have you got any rough idea on price and install ?

[azkwazere]

Honestly, i wouldt go any higher than 3.7's on a 5spd... otherwise you mayaswell get a 6speed trans aswell.

1st gear in the wet will be useless...

Both my VR V6 T5 and my VP V8 T5 will be getting 3.45's

aZk.

[Vee-ard]

Would having an Auto cause the final gearing to be different as opposed to the final gearing on a T5? IE: would the revs at highway speed be higher or lower than a T5 with the same diff?

I heard that the auto could sensibly take a higher geared diff than the T5 because of its lower ratio final gear?

[immortality]

T5 5th gear 0.72:1
4l60e OD 0.70
getrag 5th gear 0.81
T56 6th gear 0.50

so yes, with a auto you could get the next numerically higher diff ratio. if you had a T56 then you could go much higher.

as for first gear,

T5 1st gear 3.25:1/2.95:1 (V6/V8)
T56 1st gear 2.66:1
4l60e 1st gear 3.06:1

i have T5/3.45:1 diff with 17" wheels. if i launch hard, first gear lasts for about 2.5 seconds (if you get traction) before i need to pull 2nd gear. (measured with Gtech)