changing the diff gears... really make that much difference, worth the cash??????

[CHUUBZ]

Hey guys,

Got a VY SS Series 1 ute, 6 SPD manual with standard clutch and diff/diff gears looking at getting the diff shimmed cuase its starting to get sloppy and thinking about changing the diff gears at the same time but just wondering if its really worth it? Cars got 300rwkw at the moment and since I threw on some 20" VE GTS' the cars definatlly not as quick as it felt before with the 17's on it.'

Read threw some thread that 3.9.3's are the way to go on the 6spd but wondering if it really makes THAT much of a difference and also wondering how much more fuel will I be using with the different gears (at the moment I'm averaging 300km to a full tank city driving and 500km freeway driving)

Cheers,
Maciek

[Uncle Tone]

Hey guys,

Got a VY SS Series 1 ute, 6 SPD manual with standard clutch and diff/diff gears looking at getting the diff shimmed cuase its starting to get sloppy and thinking about changing the diff gears at the same time but just wondering if its really worth it? Cars got 300rwkw at the moment and since I threw on some 20" VE GTS' the cars definatlly not as quick as it felt before with the 17's on it.'

Read threw some thread that 3.9.3's are the way to go on the 6spd but wondering if it really makes THAT much of a difference and also wondering how much more fuel will I be using with the different gears (at the moment I'm averaging 300km to a full tank city driving and 500km freeway driving)

Cheers,
Maciek

I changed to 3.9's in my old VY and my fuel consumption went down!

You will notice it going up hills with less effort, and you will notice an improvement in acceleration. 3.9's are worth doing in my opinion.

[jwilson]

Hi Maciek,

What do you want from the car? Awesome torque on the street or a dyno/strip warrior?

If it's torque for regular street driving, absolutely go the 3.91's. They'll make a huge difference to how it feels when you put your foot down.

[ova400]

Its so worth it, I went 4.11s and currently have standard gears in again waiting for a new diff, and it now feels like i could push the car harder than what these diff gears do.

And yep, my fuel usage dropped and it still can do under 10l/100km on the freeway

[Oztrack Tuning]

The more power you have and the better the quality of your overall tune (not just tuned at max power) the less you will need diff gears. I have had to send 3 of my customers back to taller diff gears recently. Mine is just fast at the strip with 3.73s as with 4.11s and about 1.5L/100km better economy. Willems VZ with a M122 did 1.53s 60 footer with a 2nd gear launch on 3.07s.

With autos its nice to have a lower 2nd gear.
But with M6s they can be made to be really nice with 3.45s

[El Narros]

After my standard diff died I decided to go 3.9s, i've noticed the speedo feels a bit out and that it starts in 2nd gear a bit better. As for accelaration... no major difference. Spend ur $1200+ on some thing better. Very over rated IN MY OPINION and I felt as though I wasted money.

[chook]

Notice that Holden went from 3.7's back to 3.5's in the manuals between VZ & VE. Is anyone changing diff gears in the VE's?

[SS Enforcer]

Notice that Holden went from 3.7's back to 3.5's in the manuals between VZ & VE. Is anyone changing diff gears in the VE's?

For a start you can't compare gearing between VE and previous models as the box ratios are different.

For an unopened car I think the 3.9s are worthwhile in the manual as they make them more drivable. Mine was anyway.

There is quite a few guys changing their gears on the Ve's as well the 3.7 seem popular for the manual guys.

I put 3.45's in my a6 Ve and tbh don't think it is worthwile at all. It hasn't improved the strip times and uses more fuel on the cruise.

cheers

[indian]

Been in my mates car when he had 3.47 in a M6 and then again when he had 3.9's fitted.. I have to say and the car felt a lot livelier and it gets off the mark very well... 3.9 in a vx/vz are the way to go IMO...

[Mungrel]

I put 3.91s in my VUSS 6Spd, well worth every cent IMO!
Made the car so much more fun to drive :D

Yet, particularly on long distance i still get great economy!

Just do it :yup:

[blown ls1]

i have a customer car vy m6 ute 330rwkw it has a kaaz 3.9 1 in rear and is an exelent choice, same car has run 11.6 with that set up

[indian]

i have a customer car vy m6 ute 330rwkw it has a kaaz 3.9 1 in rear and is an exelent choice, same car has run 11.6 with that set up

Wow that is not bad going with that power at the wheels...

[mechatron]

My first mod was changing the diff ratio. I went from 3.46s to 4.11s and it made a big difference. Much better "off the mark" acceleration and it just makes all the gears a lot closer. This diff change also made every gear like the previous one => i.e. 6th now feels like 5th used to, 5th now feels like 4th used to & 1st is quite short now allowing me to explode off the line.

[markone2]

NA....300rwkw / 3.9's / 4.11's.only way to travel imho....3 cars at 1.4 sixty Ft times cannot be wrong :)

[scoot1]

I have 3.9s in a VY SS ute, Series 1, and think they are great. Still good on the highway, fuel economy still around the 10s. Makes the ute more lively around town and better for overtaking on the open road. One of the better mods I have done in my opinion.

[CSP]

My M6 VE HSV is 3.7 from the factory and I'm happy with it. It's got plenty of punch off the line, especially since my tune!

I can think of a WHOLE lot of better things to spend my money on.

[SSidewayz]

IMO diff gears totally change the way your ride will drive. I drive an M6 with 3.9's and that was prob one of the better bang for buck mods for my N/A street use daily. Very soon ill be putting 3.7's in for a go because with around 300rwkw now I reckon that they will suit a bit better. 3.9's are feeling too short for me 1st & 2nd on the street. I was talking to a few people as well and the word is that with my sort of power the 3.7's may help at the strip as well. I also see Oztrack is going the taller gears for alot of his combos now with good results all round.
PS I think 6th is a joke with stock gear ratios.

[wagnman]

as many others have said.
my VY really benefitted from the 3.9 gears. It made 6th gear useable from 90kph up (although I dont use 6th under 100kph to avoid over loading the gearbox) and made the car much nicer all round.
So many of the mods that we do to our cars are changes that you get used to very quickly that sometimes you need to drive a stock one to apreciate how nice your modded one is.

[ss ute 01]

i put 3.9's in my vu ss m6 ute. to be honest i didn't really notice f#ck all difference, if i could do it again i would of spent the money on something else

[mustanger]

i put 3.9's in my vu ss m6 ute. to be honest i didn't really notice f#ck all difference, if i could do it again i would of spent the money on something else

I dare say that would depend on what you were coming from :idea:

[DR-vyss-108]

is there a big SOTP difference with the 3.9s after coming from 3.46?

[Mungrel]

is there a big SOTP difference with the 3.9s after coming from 3.46?

IMO yess :yup:

[DR-vyss-108]

IMO yess :yup:
throttle response or the whole pull to the limiter??

[Oztrack Tuning]

If its a M6 spend the $ on other things, if its an A4 it worth going to 3.73 for sure. 3.07 makes 2nd gear too tall unless you have over 300rwkw.

[aquabat]

Have 3.9's in my R8 Clubsport. Swapped them for my old 3.46 which a bloke wanted so his single turbo SS ute would come onto boost a bit 'smoother' and make the first few gears actually useful!

I reckon it was worth it. With a 3600rpm stall convertor the car is so lively now. It rolls on really well now at 80kph, where as I felt it was pretty homo before.

Worth the swap/ money.

Jason.

[CHUUBZ]

Anywhere have any idea where the cheapest place to get the 3.9.3 gear ratios would be?