3.9 or 4.11 diff??

[SlvrR8]

Hey guys I'm looking at changing the gears In my vx clubby from the standard 3.7 gears to either 3.9 or 4.11. Any advice from people who have had it done would be great. I was leaning to 4.11 cos going 3.9 wouldn't be much difference I'd imagine. Cheers

[Buckd1ch]

You are right in saying it wont make much difference going to 3.9's. But 4.11's is just wheelspin heaven. I would reccomend test driving a car with 4.11 diff before getting it done. They arent for everyone.

[SlvrR8]

Cheers for advice, I can't justify spending over 1k on 3.9s and not feeling a diff

[SlvrR8]

Difference *

[Buckd1ch]

What other mods are done to your car? In all honesty the money could be used more wisely.. 3.7 is a nice ratio with good low down torque without sacrificing hwy fuel economy.

[LETZRIDE]

I dunno if your tranny gears are like ours, or which tranny you guys have...but if it is like ours I'll say go 3.90s...I originally had 3.90s in my car and loved them...after blowing 2 rears and putting in a ford 8.8 I didnt have a 3.90 option so I jumped up to 4.11's...I did notice a difference over the 3.90's as it took out some flatspots, but to be honest the gears are too short. I have an A4 and as you know you cant go WOT into 4th gear because of the converter locking up, 3rd gear will wind out to about 202km/h at 6500-6600 rpm which I don't like churning the car to.

Secondly my gas mileage took a BIG hit...I used to get 550-570km to a tank of gas all highway, with the same kinda driving Im struggling to push 500km to the same tank.

I'd love to have my 3.90s back...great performance and easier on the wallet.

[GRPABT1]

What gearbox you running? T56 is perfect for 4.11's with a long first gear and two big overdrives.

[SlvrR8]

My bad should of mentioned it's an M6. Mods are just mafless tuned 253rwkw. Cheers for input guys

[SlvrR8]

And I'm planning on camming it at around same time so what do use reckon. Will 4.11 be just to short with that set up? Keep in mind I only drive it on weekends etc

[Buckd1ch]

Ahh might be ok for a weekend warrior. Aslong.as your.not fussed with fuel consumption. Cam+4.11's will not be pretty in terms of fuel.

[Clint_G]

Will you only be driving it around town or highway driving also

[GEN3RATD]

4:11's for manual, 3:9's for auto

[VY Rossi]

I have 3.9s in my m6 vy ss and love them ive been told the opposite 3.9s for manual and 4.11s for auto

[SlvrR8]

Very rarely I highway as I'd drive my vt super 6 on highway trips . And I woulda thought 4.11 in an auto would rev like mad on highway being only 4 gears?? And I've been told I 6th with 4.11 still only sits under 2000rpm??

[Clint_G]

If you only really drive it around town then go 4.11.

[SlvrR8]

Thanks for the comments . Wouldn't it be a bitch to get traction at the strip tho? I Imagine it will shred tyres at a rapid rate with 4.11s and cam.

[Clint_G]

The townsville track is a pain to get traction on in any car. At first you might have a bit of trouble but after a few goes you will get the hang of launching it with the 4.11

[SlvrR8]

Yeah true I'd love to drive one with 4.11s already but don't know anyone wit them . I might just bite the bullet an get them done .

[GRPABT1]

I have 4.11's and a T56 and more power. A bigger cam will appreciate more revs around town, highway is still only about 1800rpm and as I mentioned the tall first gear suits these gears. GTS's came with 3.9's from factory, a few extra revs won't hurt and you'll love them.

[SlvrR8]

I agree mate my engine tuner said exactly that, I think im sold on the 4.11. Cheers dude

[LETZRIDE]

as long as you are going to stay N/A 4.11's are fine than...if you go F/I that gear will be too short

[GRPABT1]

Turbo's need lower ratios to help load the motor and spool the turbo but superchargers still run well with the same gears as NA motors. If you go drag racing then basically you wanna pick a ratio that puts you as close top revs over the line in 1:1 ratio gear (3rd for auto, 4th for manual) without limiter bashing.

[SlvrR8]

Yeah true ATM I cross the line in forth but only probably around4000-4500rpm not 100% sure.

[SlvrR8]

Wait no it should be higher rpm than that I think..

[GRPABT1]

With 4.11's I am crossing the line somewhere around 6000rpm (factory tacho lol). It's up there somewhere but not enough to light up the shift light which is set to about 6900. That's at 117mph.