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31's + 4:1's + 1.6 EFI + 4.6:1 diffs = Too low????

Posted: Mon Nov 23, 2009 11:26 pm
by Gutless
As the cryptic title says I have a sierra ute with 1.6 EFI, and 4.11 diffs (dead) and I am upgrading to WT's. I have been offered some 4.6 diffs, but I'm not sure if these will be too low or not.

I drive the ute 6 days a week in city and on h'way.

Will it be revving its tits off?

Opinions please. Better yet can someone tell me estimated RPM :D

Cheers
Peter

PS. it has manual sierra 5sp and 1 litre transfer.

Posted: Tue Nov 24, 2009 12:10 am
by mrRocky
maybe 350/400 rpm more id say

Posted: Tue Nov 24, 2009 7:02 am
by joeblow
not with 40" tyres. what size you running?

Posted: Tue Nov 24, 2009 9:06 am
by Gutless
31's joe.

Posted: Tue Nov 24, 2009 9:23 am
by Highway-Star
yeah I personally think that's too low. You'll be doing about 4230rpm at 100km/h in 5th.
If you got a 5 speed with the 0.79 overdrive (which I am still yet to actually see a real version of) you'll get about 3870rpm, which is probably OK.

with the 4.1 diffs you said have died, you were doing 3750rpm, or 3450 with the 0.79 o/d.


Guess it depends how much you like high rpm :D

Posted: Tue Nov 24, 2009 9:30 am
by lay80n
http://www.lepayne.com/gears.html

Knock yourself out


Layto....

Posted: Tue Nov 24, 2009 9:33 am
by dank
Going on these figures:
1.59 tranny (approx I litre high range ratio)
.86 5th gear
4.6 diff gears
31" tyres

= ~4100rpm @ 100km/h

hope that helps. Probably a touch high but at least throttle response will be sweet at 100km... as its up there!

My zook is going to be 4600rpm at 100km/h with a 20v 4age. lol. should be interesting.

Posted: Tue Nov 24, 2009 9:56 am
by joeblow
Gutless wrote:31's joe.
its gonna be borderline, depends on how quiet the cab is really. 4000rpm is what i aim for (max) at 100 kmh when gearing vehicles, but the extra 100 rpm or so may not be too bad. will be sweet off-road :D

Re: 31's + 4:1's + 1.6 EFI + 4.6:1 diffs = Too low????

Posted: Tue Nov 24, 2009 10:02 am
by JrZook
Gutless wrote:As the cryptic title says I have a sierra ute with 1.6 EFI, and 4.11 diffs (dead) and I am upgrading to WT's. I have been offered some 4.6 diffs, but I'm not sure if these will be too low or not.

I drive the ute 6 days a week in city and on h'way.

Will it be revving its tits off?

Opinions please. Better yet can someone tell me estimated RPM :D

Cheers
Peter

PS. it has manual sierra 5sp and 1 litre transfer.
If you are upgrading to WT's why not run NT 3.9:1. That will probs get you around the 3.3K@100 mark which im sure the 1.6 can pull.
Title is a tad confusing are you running 4:1 low range gear set as well? Or just the 5 speed with 1l tcase?

Dan

Re: 31's + 4:1's + 1.6 EFI + 4.6:1 diffs = Too low????

Posted: Tue Nov 24, 2009 2:05 pm
by Gutless
JrZook wrote:
Gutless wrote:As the cryptic title says I have a sierra ute with 1.6 EFI, and 4.11 diffs (dead) and I am upgrading to WT's. I have been offered some 4.6 diffs, but I'm not sure if these will be too low or not.

I drive the ute 6 days a week in city and on h'way.

Will it be revving its tits off?

Opinions please. Better yet can someone tell me estimated RPM :D

Cheers
Peter

PS. it has manual sierra 5sp and 1 litre transfer.
If you are upgrading to WT's why not run NT 3.9:1. That will probs get you around the 3.3K@100 mark which im sure the 1.6 can pull.
Title is a tad confusing are you running 4:1 low range gear set as well? Or just the 5 speed with 1l tcase?

Dan
4.1 transfer but high range is the same as 1 litre anyway.

I thought about 3.9's, but I really like the way it drives on the 4.11's.

To give you some background, I have just dropped my 1.6 8v TBI motor out (~60kw) and dropped in the 1.6 16v (~70kw) and don't want to lose the effectiveness of the extra 10kw by gearing down the diffs to 3.9's. Ideally I would like some 4.1 WT maruti centres, but they are hard to find.

If I have to I have some 32's here I can use, but they will require some trimming mods that I really didn't want to do at this point.

Pete

Posted: Tue Nov 24, 2009 3:34 pm
by mrRocky
i have 2x 4.1 diffs i would sell but alas im in perth

Posted: Tue Nov 24, 2009 3:37 pm
by Gutless
all I need is the ring and pinion gears.

How much would you want for them?

Posted: Tue Nov 24, 2009 5:11 pm
by Gwagensteve
I get 4052 rpm @ 100km/h based on an actual tyre diameter of 30.5".

I think it will OK- I've built a car that runs near 4K @ 100 and it's fine. It has a fairly quiet exhaust though.

Steve.

Posted: Tue Nov 24, 2009 6:26 pm
by 31zook
Im not keen on running my car past 3500 down a highway for ages so i would say go for it and get slighly bigger tyres.... :D

Posted: Tue Nov 24, 2009 7:22 pm
by Gwagensteve
Suzuki were happy to release the Jimny running 4K @ 100 - stock.

4K won't hurt the 1.3.

Steve.

Posted: Tue Nov 24, 2009 8:54 pm
by Gutless
Gwagensteve wrote:Suzuki were happy to release the Jimny running 4K @ 100 - stock.

4K won't hurt the 1.3.

Steve.
I have a 1.6 :D

I think it will be fine too. I don't do long distance highway ( bout 1hr max at a time) so I'm not too concerned with 4K-ish.

My swift sport does 4200 @ 110 so whats the difference really?

Posted: Tue Nov 24, 2009 9:24 pm
by mr green
Gutless wrote:all I need is the ring and pinion gears.

How much would you want for them?
when the father in-law owned my maruti, he paid around $340 for a ring and pinion new through suzi care.
ps. the 4.3 out of the gv front would be favourite diff ratio, might also be a good compromise if their price is right

Posted: Tue Nov 24, 2009 9:49 pm
by Gutless
Yeah the 4.3 would be better.

Does anyone out there with 4.3's wanna swap for 4.6's? :D

gf

Posted: Wed Nov 25, 2009 9:56 pm
by sic_zook
peter just run the 4.6 gears n try them i ran 5.1 with efi 1.6 n a cut n shut n 31s n it was around about 4g but could put your foot down n get about 140 out of it in 5th without hiting the limiter

Posted: Thu Nov 26, 2009 8:16 am
by christover1
I run 4:9 diffs, 1.o litre t-case and a 1.3 5speed with 31's
Off road brilliant, on road acceptable, but could use a 6th gear at times.
I think 4:6's would be ok, inho.
4:6 was my choice, but when I got home, had 2 x 4:9's so I went with that :roll:
NB to myself. Check your ratios before buying, make sure both ends same :idea:

Posted: Thu Nov 26, 2009 9:49 am
by Gutless
Alright, thanks for all the comments fellas.

I'll try the 4.6's with 235/85 16's and see how it goes.

Cheers
Peter