Jimny gearing for 33+ tyres

All tech relating to the newest bread of suzuki 4x4s
stimpy
Engaged 4wd low
Engaged 4wd low
Posts: 101
Joined: Mon Nov 14, 2016 10:03 pm

Re: Jimny gearing for 33+ tyres

Post by stimpy » Mon Mar 06, 2017 10:14 pm

Scottie - what tranny box and final drives are you running in your Zook?

User avatar
ScottieJ
The Boss
The Boss
Posts: 11596
Joined: Tue Apr 15, 2008 12:13 pm
Location: Chippenham, wiltshire

Re: Jimmy gearing for 33+ tyres

Post by ScottieJ » Mon Mar 06, 2017 11:09 pm

Anton wrote:Sammy axles or 413 axles are narrower?

The Jimny has a wider track than the Sammy?
Yep wider than sammy
Zuki Build

Steady as she goes!

User avatar
ScottieJ
The Boss
The Boss
Posts: 11596
Joined: Tue Apr 15, 2008 12:13 pm
Location: Chippenham, wiltshire

Re: Jimny gearing for 33+ tyres

Post by ScottieJ » Mon Mar 06, 2017 11:23 pm

stimpy wrote:
Hehe...

The chap i bought it off has had it 6 years on standard box and axles so he's either been lucky or very careful..

I suspect i will be much harder on it so will find the limit of things :lol:

It seems a few folk are using the trail gear 6.5:1 set up. That in itself obviously affects other areas and of course the gearing on the road which frankly one doesn't want to go too quick in it for fear of certain death!!
He was probably ok because without the lower gearing and a stock 1.3 it barely has the torque to move let alone break stuff.

I'm running stock 3.727 diffs and just a 410 tbox behind the doubler (1.580 hi-hi /2.511 hi-lo), but it does have a 1.6 so that helps. Could do with being lower on road with some 4.3 diffs but it'll still motor along well until I get to a steep hill :lol: happily cruises along a 60-70mph on road. I have 4.56 in lo-lo box and it's good, used to run a 4.16 on the back of the doubler so had 7.55 lo-lo but that was just too low most of the time so I only really shifted the 4.16 into lo.

Really it's best to spread the reduction between diffs and the tbox but I've not had issues, however I do have a full float rear conversion and chromo shafts and CVs :mrgreen:
Zuki Build

Steady as she goes!

stimpy
Engaged 4wd low
Engaged 4wd low
Posts: 101
Joined: Mon Nov 14, 2016 10:03 pm

Re: Jimny gearing for 33+ tyres

Post by stimpy » Tue Mar 07, 2017 7:42 pm

Thanks mate.

And yes, with the asthmatic power of the standard 1.3 id imagine it would be tricky to get into a position of trouble in the first place!!!

Going for a play this weekend, don't imagine ill be out of 1st gear low all day.....

Spoke to Rich (RW) earlier today which was insightful as ever. Seems little point swapping thew diffs for little reduction, and it will be a 5:1 box needed...

Cheers

stimpy
Engaged 4wd low
Engaged 4wd low
Posts: 101
Joined: Mon Nov 14, 2016 10:03 pm

Re: Jimny gearing for 33+ tyres

Post by stimpy » Wed Mar 08, 2017 4:09 pm

Just an update to say that i spoke to Rob (RS) and he reckoned a 6:1 was correct for 33s.

I think it will very much be dependant upon true tyre size , with remoulds generally measuring larger than stated and manufacturers being smaller sometimes....

Gutted i missed a 5:1 by days in the classifieds! If anyone has anything stashed away please let me know....

Anton
I spend far too much time on here
I spend far too much time on here
Posts: 3859
Joined: Tue Jan 12, 2010 12:12 pm
Location: London

Re: Jimny gearing for 33+ tyres

Post by Anton » Wed Mar 08, 2017 6:58 pm

Swapping in a 5:1 or even 6:1 is probably the quickest and cleanest option, sure - but not always the cheapest. If you can get the diffs cheap and have a 4.16 rocklobster lying around (like I do) then that makes the most sense.

But then I have a 413, not a Jimny. ;)
1985 SJ413VX (SJ50V) with SPOA, rear disc brakes, 31x10.5R15 Kaiman Malatesta tyres, an MOT and a lot left to do!

My: Build thread To-do list Pay and Play map

stimpy
Engaged 4wd low
Engaged 4wd low
Posts: 101
Joined: Mon Nov 14, 2016 10:03 pm

Re: Jimny gearing for 33+ tyres

Post by stimpy » Wed Mar 08, 2017 8:44 pm

Anton wrote:Swapping in a 5:1 or even 6:1 is probably the quickest and cleanest option, sure - but not always the cheapest. If you can get the diffs cheap and have a 4.16 rocklobster lying around (like I do) then that makes the most sense.

But then I have a 413, not a Jimny. ;)
Haha!! Definitely cheaper mate....

But it would take more time and when doing the diffs you'd end up doing a load of "while you're in there" stuff... And sadly i just don't have time these days else i'd be building a LWB sami :-)

User avatar
ScottieJ
The Boss
The Boss
Posts: 11596
Joined: Tue Apr 15, 2008 12:13 pm
Location: Chippenham, wiltshire

Re: Jimny gearing for 33+ tyres

Post by ScottieJ » Thu Mar 09, 2017 8:44 am

stimpy wrote:
Gutted i missed a 5:1 by days in the classifieds!
sorry ;)
Zuki Build

Steady as she goes!

User avatar
ScottieJ
The Boss
The Boss
Posts: 11596
Joined: Tue Apr 15, 2008 12:13 pm
Location: Chippenham, wiltshire

Re: Jimny gearing for 33+ tyres

Post by ScottieJ » Thu Mar 09, 2017 12:22 pm

Some food for thought.

Presuming that your jimny has 3.909 diffs at the moment and the Tbox is 1.32 in hi and 2.145 lo (i don't know what year, engine it is so that's a guess??)

As stock they run 205/70 tyres so 26" tall.

This means stock is
hi 5th at 4000rpm= 59.9mph
lo 5th at 4000rpm= 36.9mph

With a true 33" tyre, a 4.16:1 tbox and 4.3 diffs.
hi 5th 4000rpm= 57.8mph
lo 5th 4000rpm= 21.9mph

33s, 4.16:1 tbox with 4.090 diffs.
hi 5th 4000rpm= 60.7mph
lo 5th 4000rpm= 23.1mph

33s, 5.1:1 with 3.909 diffs
hi 5th 4000rpm=58.9mph
lo 5th 4000rpm= 19.7mph

33s, 6:1 with 3.909 diffs
hi 5th 4000rpm=57.7mph
lo 5th 4000rpm= 16.7mph

So There's not really much in it at all. I actually think a 4.16 box and 4.3 diffs would be the best option, it's actually lower in low than my sj.
Zuki Build

Steady as she goes!

stimpy
Engaged 4wd low
Engaged 4wd low
Posts: 101
Joined: Mon Nov 14, 2016 10:03 pm

Re: Jimny gearing for 33+ tyres

Post by stimpy » Thu Mar 09, 2017 6:57 pm

ScottieJ wrote:
stimpy wrote:
Gutted i missed a 5:1 by days in the classifieds!
sorry ;)
You bugger!!

Wanna sell it?? :brows:

Post Reply