[my99jimny]

Hi I have a 99 manual jimny and at 100k's its reving at 4grand and this seems pretty high to me I would have thought it would be more like 3grand and was wondering if anyone has changed the diff ratios in there jimny to lower the revs? or if any one could tell me what the diff ratio would be thats in it now or even what ratio would I have to go to in order to get the revs down for better highway driving.
Thanks
Adrian

[Fatzook]

you have 3.9 ratios. 4 grand is normal for a jimny. If you want to lower the revs a little, you could go up a size or two in tyres, but that will effect your acceleration and speedo.

[Taff]

they are meant to rev. its only a little engine

at 3k you would be stuffed with a headwind.

[ninjadaniel]

Jimny's can have 4.11 or 3.9 ratios. The 4.11 is supposed to be reserved for autos but my manual Jimny had 4.11 front diff (can never be sure who stuffed with the car)

A quick way to check is to jack up the rear of the car, chock 1 wheel to stop it spinning, put a piece of metal or a screwdriver in the universal at the diff end, have a friend spin 1 wheel exactly 1 rotation, chock that wheel and have your friend spin the other wheel exactly 1 rotation in the same direction as the first. Taking note of the object you used to mark the universal positon, if your universal spun almost 4 times then its a 3.9, if it spun slightly further than 4 rotations then its a 4.11.

I know this sounds dodgy but when you REALLY don't want to pull your diff apart... it works.

[joeblow]

don't go by manufacturer stated literature. every jimny driveline i have worked on whether it be manual or auto is of the 4.09 (yes, not 4.11 thats maruti). a suzuki dealership may also confirm this as years ago jimny diffs were, and might still be, blowing up left right and centre, so replacement diffs were needed. all that suzuki had listed for australian spec models was the 4.09, for both man and auto.

[my99jimny]

cool I will jack it up and give it a spin to see what I have got.
Auto diff centers might be a cheap way to drop the revs a bit. I am also thinking of putting the twin cam head on so the bit of extra power will help with the loss of torque I dont realy want to run taller tyres just yet as the ones on it are pritty good. also my jimny doesnt have power steering and I want to put it in and go bigger and wider tyres one day.

[joeblow]

getting you're revs down to 3 grand will do two things, it will drink heaps of juice and have absolutely no power. the 16 valve jimny head is a fantastic bit of engineering, a gti head is a dinosour and won't give you any power increases, also a gti head on a 'bb' block is not the most legal of engine mods.

[dank]

Hey Joe I noticed the other day the Jimny uses same airlocker part numbers in the rear as the leafy sierra. is it possible that rear jimny crown wheel and pinion will bolt up to a leafy sierra centre?

It might be an option for people to lower their diff ratios from 3.7 to 4.09..not a huge reduction but could make a vehicle a little more driveable in conjunction with transfer gears....

[ninjadaniel]

yeah sorry, i meant 4.09! its been a while since i had a Jimny- moral of the story is you usually get either less or more than 4 rotations

[joeblow]

dank wrote:

Hey Joe I noticed the other day the Jimny uses same airlocker part numbers in the rear as the leafy sierra. is it possible that rear jimny crown wheel and pinion will bolt up to a leafy sierra centre?

It might be an option for people to lower their diff ratios from 3.7 to 4.09..not a huge reduction but could make a vehicle a little more driveable in conjunction with transfer gears....

yep, you could bolt the whole third member in and that of a maruti (wt) too.

[my99jimny]

joeblow wrote:

getting you're revs down to 3 grand will do two things, it will drink heaps of juice and have absolutely no power. the 16 valve jimny head is a fantastic bit of engineering, a gti head is a dinosour and won't give you any power increases, also a gti head on a 'bb' block is not the most legal of engine mods.

My jimny is a 99 model I dont have much experence with suzuki's but I am pritty sure mine only has a single cam engine

[joeblow]

my99jimny wrote:

joeblow wrote:

getting you're revs down to 3 grand will do two things, it will drink heaps of juice and have absolutely no power. the 16 valve jimny head is a fantastic bit of engineering, a gti head is a dinosour and won't give you any power increases, also a gti head on a 'bb' block is not the most legal of engine mods.

My jimny is a 99 model I dont have much experence with suzuki's but I am pritty sure mine only has a single cam engine

yes, but you have 16 valves just like the gti engine. the extra cam won't make a difference.

[my99jimny]

wow i did know it was a 16valve single cam engine I just thought as it had a single cam it would only have 8valves thanks for that saved me alot of hassel for no gain

[zukenutter]

The Jimny will happily sit on 4000RPM all day long. Mine has taller tyres but also 24% reduction in the transfer case, end result being that at 100km/hr the engine spins at 4750RPM. I'm considering some even bigger tyres to make highway driving bearable. 4200RPM would be great.

I replaced my rear diff centre late last year. Was definitely 1:4.09.

I don't know if it's true or not but I heard somewhere that auto Jimnys have a different ratio in the Transfer case.?.?

[markil]

I've been driving my girlfriends jimny to work the last couple of weeks, it's a 2008 model i think, and at 4000rpm in 5th it does 118-120km/h. At 3000rpm it does around 90km/h. Has it got different ratios or are the transfer gears different? It doesn't have a lever, it's button activated off the dash ie. 2WD, 4WD, 4L

[my99jimny]

joeblow wrote:

dank wrote:

Hey Joe I noticed the other day the Jimny uses same airlocker part numbers in the rear as the leafy sierra. is it possible that rear jimny crown wheel and pinion will bolt up to a leafy sierra centre?

It might be an option for people to lower their diff ratios from 3.7 to 4.09..not a huge reduction but could make a vehicle a little more driveable in conjunction with transfer gears....

yep, you could bolt the whole third member in and that of a maruti (wt) too.

so if I get a 3.7 sierra diff that would get me where I want to go? would it fit straight in?

[zukenutter]

markil wrote:

I've been driving my girlfriends jimny to work the last couple of weeks, it's a 2008 model i think, and at 4000rpm in 5th it does 118-120km/h. At 3000rpm it does around 90km/h. Has it got different ratios or are the transfer gears different? It doesn't have a lever, it's button activated off the dash ie. 2WD, 4WD, 4L

Sounds about right for stock Jimny

[mnemonix]

my99jimny wrote:

joeblow wrote:

dank wrote:

Hey Joe I noticed the other day the Jimny uses same airlocker part numbers in the rear as the leafy sierra. is it possible that rear jimny crown wheel and pinion will bolt up to a leafy sierra centre?

It might be an option for people to lower their diff ratios from 3.7 to 4.09..not a huge reduction but could make a vehicle a little more driveable in conjunction with transfer gears....

yep, you could bolt the whole third member in and that of a maruti (wt) too.

so if I get a 3.7 sierra diff that would get me where I want to go? would it fit straight in?

It sounds like you're still wanting to ignore the advice you've been given above, re: poor fuel consumption and loss of driveability.

Also, wouldn't the reverse rotation/high pinion setup in the jimny front prevent you from using a standard sierra centre?
A normal sierra can use jimny rears at either end, but a jimny can only use a jimny diff up front, so you're shit out of luck with ratio swaps?

[my99jimny]

[quote]
It sounds like you're still wanting to ignore the advice you've been given above, re: poor fuel consumption and loss of driveability.

Also, wouldn't the reverse rotation/high pinion setup in the jimny front prevent you from using a standard sierra centre?
A normal sierra can use jimny rears at either end, but a jimny can only use a jimny diff up front, so you're shit out of luck with ratio swaps?[quote]

lol I am not ignoring anyone i am taking in eveyones advice but at the end of the day its my car also I have decided to aim for 3500rpm at 100ks but as yet I cant seem to find anyone who makes the diffs that will work for me so I might have to leave this idea for a later date

[joeblow]

there are NO diffs.

[Fatzook]

my99jimny wrote:

Quote:

It sounds like you're still wanting to ignore the advice you've been given above, re: poor fuel consumption and loss of driveability.

Also, wouldn't the reverse rotation/high pinion setup in the jimny front prevent you from using a standard sierra centre?
A normal sierra can use jimny rears at either end, but a jimny can only use a jimny diff up front, so you're shit out of luck with ratio swaps?

Quote:

lol I am not ignoring anyone i am taking in eveyones advice but at the end of the day its my car also I have decided to aim for 3500rpm at 100ks but as yet I cant seem to find anyone who makes the diffs that will work for me so I might have to leave this idea for a later date

Larger tyres are your only option.

[my99jimny]

yeah taller tyres were what I was thinking also, does any know how tall you can go with standard ride height I dont fancy the idea of them rubbing.

[zukenutter]

215/75R15 should fit and will give roughly about a 6% drop in RPM

[09JimnySierra]

my99jimny..i'm with you if you find a solution to bringing the revs down let me know....i've being looking at the fairey overdrive path.

mnemonix....how do you explain my G202 Charade...16v Single cam 1.3l sitting on 3000rpm in fifth @ 120kmh...without undue loss of power and far better economy than a brand new vvt 1.3l Jimny????

[mnemonix]

09JimnySierra wrote:

mnemonix....how do you explain my G202 Charade...16v Single cam 1.3l sitting on 3000rpm in fifth @ 120kmh...without undue loss of power and far better economy than a brand new vvt 1.3l Jimny????

Not knowing the relevance of what you're getting at here.
Although I'd be tempted to consider: A lighter car, less power lost through the FWD drivetrain, better aerodynaics and a different torque/power curve of the daihatsu engine to name a few.

My DD hyundai does approximately the same revs at 110km (I don't choose to sit on 120km/hour. your choice), and gets ~500km to a tank. But as above, not sure of the relevance...?

[joeblow]

09JimnySierra wrote:

my99jimny..i'm with you if you find a solution to bringing the revs down let me know....i've being looking at the fairey overdrive path.

mnemonix....how do you explain my G202 Charade...16v Single cam 1.3l sitting on 3000rpm in fifth @ 120kmh...without undue loss of power and far better economy than a brand new vvt 1.3l Jimny????

and the tyre size and ratios of the charade are?.......love it when people compare the revs of a 'car' to that of a '4x4'. if you want the revs of a car....buy a car or do some research before buying a 4by. trying to get the revs down too far will not be beneficial in any way. and as far as claims to a charade being more efficient than a vvt jimny....highly unlikely. i know those engines too well and they are not that flash....(the charade that is!)

[09JimnySierra]

joeblow...i own both so can easily attest to the economy of both

Running up and down the highway 1250ks a week in total the Charade is easily getting 650-700ks out of 35litres the Jimny is pushing hard to get 500ks out of 35litres....alll in all still not a huge level of consumption at the end of the day.
Previous cars have been a FJ40 troopy with the old 4H motor on Gas (dual Fuel), 2.8D hilux dual cab and 2x MQ patrols (shorties) in diesel and turbo diesel....non of those cars sat at 4300rpm to do 120kmh ???

tyre size and ratio of the charade are std...unchanged

[kenn]

09JimnySierra wrote:

Previous cars have been a FJ40 troopy with the old 4H motor on Gas (dual Fuel), 2.8D hilux dual cab and 2x MQ patrols (shorties) in diesel and turbo diesel....non of those cars sat at 4300rpm to do 120kmh ???:)

I bet they didn't happily rev to 7000 rpm either Or were quite as nimble off road as well
Anything under 3900 rpm in a Jimny and your off the cam without much power and not lot of a fuel economy gain.

[jimbo_jones]

I have heard that a Coily front gears will fit in the jimny can anyone confirm this? I’m also wanting to lower my Hey revs I’ve got a M18 so not worried about power loss

[pete_79]

jimbo_jones wrote:

I have heard that a Coily front gears will fit in the jimny can anyone confirm this? I’m also wanting to lower my Hey revs I’ve got a M18 so not worried about power loss

I’ve heard that Jimny front gears fit in a coily....

Or more the point, I’ve seen what happens when some fool puts Jimny gears in the front of a coily and leaves the coily gears in the rear..