Diff Ratios

[Mike Lowrey]

Hi I have a 2008 VE SS manual. It’s making 484hp at rear wheels, and is essentially a second car/toy. My question is I’ve blown the diff and I’m upgrading to a Trutrac, however I don’t know which ratio to choose a 3.9, or a 4.11 which would be more suitable? Given the fact that the car has a massive cam, sits on Nolethine engine and gearbox mounts, and breaths through pretty much 3 inch straight exhaust with no cats, I’m not looking for fuel economy, just performance.

 

[Crunchy Granola]

Hi I have a 2008 VE SS manual. It’s making 484hp at rear wheels, and is essentially a second car/toy. My question is I’ve blown the diff and I’m upgrading to a Trutrac, however I don’t know which ratio to choose a 3.9, or a 4.11 which would be more suitable? Given the fact that the car has a massive cam, sits on Nolethine engine and gearbox mounts, and breaths through pretty much 3 inch straight exhaust with no cats, I’m not looking for fuel economy, just performance.

In your case mate the answer is easy, 4.11. Or what the hell go 4.55s.

 

[losh1971]

3.9 will be about 1900rpm at 100kph. I say 3.9.

 

[someguy360]

3.9 will be the most comfortable for a street car while delivering the poke you want.

I love 4.11's but if you ever think your going to go for a nice senic drive or a highway drive on a weekend they can get a bit annoying.

 

[Pollushon]

Depends what you're after and where you make power. While mines not a VE I make nearly 600hp on a T56 (similar ratios) and have a 3.9 Truetrac. While it is fun and the acceleration is premium it can also hold you back, as I'm making four changes before the traps on the 1/4 and she'll spin up to fourth. The sequential shifter helps. First is useless and it's hell in the wet. So it's fun to track and spirit the streets but it's not a drag car.

All that said, there's bugger all noticeable difference from 3.9 to 4.11, pick whichever suits your budget. I'm going to move back to a 3.45 or lower to stretch its legs. I have 820nm of torque mind you

 

[Mike Lowrey]

3.9 will be the most comfortable for a street car while delivering the poke you want.

I love 4.11's but if you ever think your going to go for a nice senic drive or a highway drive on a weekend they can get a bit annoying.

What would the rpm be in sixth at 100kph with a 4.11

 

[Mike Lowrey]

Depends what you're after and where you make power. While mines not a VE I make nearly 600hp on a T56 (similar ratios) and have a 3.9 Truetrac. While it is fun and the acceleration is premium it can also hold you back, as I'm making four changes before the traps on the 1/4 and she'll spin up to fourth. The sequential shifter helps. First is useless and it's hell in the wet. So it's fun to track and spirit the streets but it's not a drag car.

All that said, there's bugger all noticeable difference from 3.9 to 4.11, pick whichever suits your budget. I'm going to move back to a 3.45 or lower to stretch its legs. I have 820nm of torque mind you

 

[Mike Lowrey]

I just want to get the best out of the car, I still dont want it screaming it’s head off at 100kph but want to get the best spread with the power I’ve got.

 

[Pollushon]

It won't scream. It has six gears, plenty comfortable on cruising

 

[losh1971]

I have 3.9s on NA and I'm happy with where I'm at. You won't need 4.1s with boost.