[bulldoggy]

Hey guys trying to decide what gears to go not sure on the 6.5 or 4.9s.

For those with the stock 1.3ltr motor and 3.9 diff gears who run 6.5 is it screaming it's head off at 100kph? or is it ok?

Learning zooks as i go coming from the toyota background.
Cheers

[want33s]

Revs at speed will depend on your chosen tyre size.

[5ierra]

I Have 31's with 5.12 (or 4.8 :S) dif gears and i get about 4000-4200rpm at 100Km/h

Its just a given when you get bigger tyres.

[S13RR4]

5ierra wrote:

I Have 31's with 5.12 (or 4.8 :S) dif gears and i get about 4000-4200rpm at 100Km/h

Its just a given when you get bigger tyres.

dont wanna sound like a dick and all, but wouldn't bigger tyres give you lower revs?

the tyres have a bigger circumference so the diffs, and therefore engine would only need to spin at a lower rpm to achieve the same speed?

wouldn't the reduction gearing in either the diffs or TC be responsible for increasing the revs??

[appsie]

if your running 3.9 diff gears and going to 6.5 imo it will be to low for most driving.i have 3.7 and 6.5 on 31s but have now also gone to 1.6 efi.It used to be ok with the 1.3 and now i sit on about 3600 at 100 which aint too bad.
A mate who used to be on here had 3.9s,6.5s and 33s and we both crawled about the same in the bush,unsure of his revs up the road,also on 1.6 efi

i take it yours in NT?you really cant beat 6.5s for the price i say

[bulldoggy]

Mine is a wide track but has NT gears in it.

As tyre size increases revs decrease, as mentioned above. if i go to 31s now i will loose 5th. But all Tcases i have run were 1:1 but the zook alters hi range gearing also. So that will solve that just unsure whether 4.9 or 6.5 dont want to be in the 4k rev range at 100 though i don't know much about zooks and whether that is to high as having mainly diesels that redline at 5.5k.
Thanks for the input sensus seems to be 6.5???

[shep]

i have small 31s and 6.5s and i would like it to rev a bit higher at 100kph.
i reckon 4000 at 100kph would be perfect.

[Highway-Star]

they like to rev... My LJ gets better fuel economy then my injected Sierra, and it sits on around 5000rpm on the highway ....anyway I digress....

I have 4.9's and 3.7's on 31's, and I wish it revved more on road. I think the 3.9's would make this nice on road (around 3700). Offroad is fine, 1st is a nice crawl gear, and 2nd is a nice "punch it" gear.

I've seen 6.5's with 31's, it works fine, just different gear spacing to what I am used to. 3.9 diffs will make it rev allot at highway speeds, but probably not too much.

[shep]

the difference between 3.7s and 3.9s is very small. i doubt that it would be noticeable.

[lump_a_charcoal]

I have 31s, 6.5s and 3.9s, and it is fie for my driving, however it could be a little better as I am doing 4000 at about 110km.

[squirezook]

shep wrote:

the difference between 3.7s and 3.9s is very small. i doubt that it would be noticeable.

I would agree but I change my diffs to wt and noticed the difference straight away. I did put a wider body/tray on at the same time so wind resistance increased. @ estimated 100 k revs are at 3000 rpm fuel consumption went up Running 31"
Need transfer gears 6.5's I reckon.
Need money for gears first.
Need job first.

[shep]

squirezook wrote:

shep wrote:

the difference between 3.7s and 3.9s is very small. i doubt that it would be noticeable.

I would agree but I change my diffs to wt and noticed the difference straight away. I did put a wider body/tray on at the same time so wind resistance increased. @ estimated 100 k revs are at 3000 rpm fuel consumption went up Running 31"
Need transfer gears 6.5's I reckon.
Need money for gears first.
Need job first.

3.7 to 3.9 is less then %5 gearing change, because your gearing is so crappy
any little bit helps. your tyres are around 20% bigger so it stands to reason
that you will need at least 20% gearing change to get back to standard
performance. of coarse that's not taking into account the wider and heaver tyre.

[JrZook]

squirezook wrote:

shep wrote:

the difference between 3.7s and 3.9s is very small. i doubt that it would be noticeable.

I would agree but I change my diffs to wt and noticed the difference straight away. I did put a wider body/tray on at the same time so wind resistance increased. @ estimated 100 k revs are at 3000 rpm fuel consumption went up Running 31"
Need transfer gears 6.5's I reckon.
Need money for gears first.
Need job first.

3000rpm at 100 ouch!! The 1.6 MPFI likes its revs to be around 3600rpm to be comfortable at that speed.

[bulldoggy]

Okay then if they like to rev i'll go with the 6.5s if their no good someone can buy them .
Cheers

[Merk]

I run 31's and 6.5's on the road and it's perfect at 100ks, sits at about 3600rpm. Anything lower and It would struggle a lot I would think. And as others have said, they love to rev. Go the 6.5's, they are way cheaper and if you decide to go 33's in the future you'll be set.

[jdk81]

I have 6.5s and use stock tyres as daily. it revs at 4500 at 100km/h.

When I put the muddies on its about 3100 at 100 km/h.

I would prefer it to be reving at about 3600 rpm, as I find thats where I get best fuel consumption.

Given my time again, I would much prefer changing diff ratios and whacking different ratio xfer gears, as I rarely ever use 1st low.

[31zook]

mine does 100kph @ 3100rpm. Im very happy with it, i shift at about 3000rpm everywhere except if im overtaking traffic. I return about 8L on the highway and about 10-11L in town. I wouldn't setup my gearing any other way....

I drive a lwb sierra with stock tyres and gearing. shall be 30x9.5s and a rock lobster soon... just gotta find a set of tyres first....

[shep]

31zook wrote:

mine does 100kph @ 3100rpm. Im very happy with it, i shift at about 3000rpm everywhere except if im overtaking traffic. I return about 8L on the highway and about 10-11L in town. I wouldn't setup my gearing any other way....

I drive a lwb sierra with stock tyres and gearing. shall be 30x9.5s and a rock lobster soon... just gotta find a set of tyres first....

the only stock sierra that i have had was doing 80kph at 3000rpm in top, so i reckon that either ya speedo or your tacko is wrong.

[31zook]

yeah? there is bugger all rev difference between 80 and 100 on my car...

what is the stock tyre size? i have 3.9s and 205s would that make it way off?

[MacDaddy]

Highway-Star wrote:

they like to rev... My LJ gets better fuel economy then my injected Sierra, and it sits on around 5000rpm on the highway ....anyway I digress....

I have 4.9's and 3.7's on 31's, and I wish it revved more on road. I think the 3.9's would make this nice on road (around 3700). Offroad is fine, 1st is a nice crawl gear, and 2nd is a nice "punch it" gear.

I've seen 6.5's with 31's, it works fine, just different gear spacing to what I am used to. 3.9 diffs will make it rev allot at highway speeds, but probably not too much.

X 2
The Zook engine is made for high revs, they redline at 6000rpm..., 4000rpm at 100kph is right, 3800 to 4200rpm is the norm, and 4600 to 4800 at 110 to 120kph...

[steak_knife]

Highway-Star wrote:

they like to rev... My LJ gets better fuel economy then my injected Sierra, and it sits on around 5000rpm on the highway ....anyway I digress....

I have 4.9's and 3.7's on 31's, and I wish it revved more on road. I think the 3.9's would make this nice on road (around 3700). Offroad is fine, 1st is a nice crawl gear, and 2nd is a nice "punch it" gear.

I've seen 6.5's with 31's, it works fine, just different gear spacing to what I am used to. 3.9 diffs will make it rev allot at highway speeds, but probably not too much.

That's what I am thinking would be the perfect combination.

In my opinion the 6.5's are to low for a car that needs to be driven on the road for more than 5km to get to the track's.
But that is on 31's tho..

[Crunched]

Agreed. I have 4.9's, 31's and 3.7's in mine and I would love just a slight reduction on road, which I think the 3.9's would be perfect for. The way it is now, 4th gear revs it's tits off but there's not enough grunt to hold 5th up even the slightest incline.

Offroad, the 4.9's, 31's and 3.7's are perfect - mostly using 2nd and 3rd gear with 1st only for real crawling stuff. I think 6.5's would be overkill unless you were planning to go to 33's at some stage.

And aren't you going 1.6EFI??

[steak_knife]

Crunched wrote:

And aren't you going 1.6EFI??

Yes, but 6.5's are still to low in high range..

IMO

[MrRocky]

I have 4.1 diffs and 6.5 gears with 31's and sit on about 4000rpm
in 5th gear doing 100km/phr i can maintain that speed up any incline with the 16v 1.6. To be honest its a little to low i would like to change it to 3.9's in the future

[alien]

im running calmini 5.14 tcase gears and 31's... tcase would be 3.7 i think? (92 WT) ... anyway - the 5.14s were about 19% reduction in high range and about 180% low range and its spot on for me. 100km/hr is around 3500rpm and its great, as i can still grab 4th if need be and use 5th for cruising.

[Crunched]

steknig wrote:

Crunched wrote:

And aren't you going 1.6EFI??

Yes, but 6.5's are still to low in high range..

IMO

That was my point - with the extra horsies you won't need to go lower...

[Moph]

I'm running 6.5's, 3.7's, 31's and stock 1.3L - am very happy with it. Pulls a loaded camper trailer at 100kph in 5th / 110kph in 4th ... awesome engine braking on descents ... more than enough usable speed in 1st-4th Low (I swap to High if moving between sections). Would think either 4.9's or 6.5's would be fine with 3.7's and 31's depending on your driving style (crawling vs sand/mud).

[DMAC]

I run 29" tyres with 6.5 transfer gears everything else is stock. 94 WT Sierra

3800rpm at 100km/hr (GPS speed)
Stock is 3600 rpm at 100km/hr I checked this prior to changing tyres and transfercase.

Yes low range is low. Great for driving on rocks.

31s would be very close to stock in high range.

[steak_knife]

I'm running 3.9's tho.

i can't see the point of having 2 gear's in low that you need to be almost vertical to use.
Mr DMAC, how often do you actuality use 1st low & for how long would you be in said gear??

Cause I'm in the market for gear's & can't make my mind's up..

[steak_knife]

http://www.lowrangeoffroad.com/suzuki/s ... gears.html

Reading here, it's says the gear's are "Rock monster"

I've been told thay brake, can anyone confirm this??