VE SSV M6 Diff Replacement

[scumbo]

Hi Guys, well the Std Diff has given up and started making some nasty nasty noises and I'd say it's not much time before it completely dies. Being a Manual it obviously has the 3.45 ratio. As I have to now replace the diff I was wondering if I should go 3.7's or 3.9's. Car is a daily driver and does freeway driving. Mods are OTR, Tune, Headers & Exhaust.
Scumbo

 

[MYVESSV8]

3.7's seem to be the go-if you do a lot of freeway driving

 

[scumbo]

Thanks MYVESSV8 for at least replying unlike the other 100

 

['ssv']

I drive 38km's one way on the freeway to and from work every day for the past 6 months.
4:11's are the way to go.

Your changing the raio to go faster yes? Why would you change to the not so fast ratio?
Sits around 2000rpm @ 110kph and pulls up hills with out having to use more fuel.
Plus 6th gear is actually usable at any speed over 80 so you'll use less fuel if you travel around that speed alot.

the difference at the traffic lights between 3.45 and 4.11 is huge. You'll be up and out of there a lot quicker

 

[scumbo]

Thanks ssv, exactly what I was after, after speaking with several people I'v pretty much settled on 3.9's . My only concern was the fuel consumption and revs at freewaty speed. So if your's is doing 2000rpm at 110, the 3.9's should be pretty much on the money for me. thanks for the feedback.
cheers

 

[MYVESSV8]

good too see you've picked you set up, interesting info ssv, how would it go then on a prolonged run from Sydney, Brissy return

 

[brasher]

you have a 6L v8, fuel consumption shouldn't be in your dictionary

 

[ducker85]

Sits around 2000rpm @ 110kph

That doesn't sound right, my cars stock and it revs higher, around 2200rpm@110km and from what I've read and believe I have a 6 speed with 3.7s. Dads SSV was 6 speed with 3:45s and it sat around 1900rpm@110km. Generally each ratio adds 200rpm so I would think a 4:11 would be around 2600rpm@110km.

Not saying your wrong, just surprised and now interested to know more.

 

[ducker85]

Actually I think mine revs higher because the HSV gear box has different ratios in it. I can't remember now so I might be completely off

 

[K-Man]

I had 3.7's installed with my Head and Cam job.

Sits at about 1650 @ 90Kph (Damn SA roads, 90 is the new 100), yet the ratio is high enough for it to really boogie from a standing start, and 2nd gear still tops out @110kph if you really want it to.