Hey guys I've converted my BA XR6 turbo form a 4 speed to a 6 speed manual and it goes great mid range 3,500rpm to high making 300rwkw.

It feels VERY sluggish down low before boost hits not because of a mechanical problem or anything like that it just seams not as responsive or jumpy off the line and I'm thinking this could be dew to the STOCK BA 4 speed turbo diff gears being a 3.45 and the 6 speed being a 3.73.

It wheel spins like a boss off the line or bogs down can not find an in-between (may be dew to my driving but still feels like the car is asleep down low in normal driving)

Thoughts on diff gears to waken the thing up a bit or any other ideas?

I've read the other threads but nothing really specific to my situation.

3.45 I think is stock on xr6 with six speed. 3.73 is FPV

My mistake then, I must have 3.23 ratio. And that makes it even more sluggish down low than the 3.45 haha

Thoughts?

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Both are 3.73 stock.

If you go lower you'll get more wheel spin when it comes on boost but it will be larger coming on.

Got higher and you place more load on the driveline so it will build boost quicker but may result in wheel spin.

3.73 is the best compromise, that and working on your driving style.

Both are 3.73 stock.

If you go lower you'll get more wheel spin when it comes on boost but it will be larger coming on.

Got higher and you place more load on the driveline so it will build boost quicker but may result in wheel spin.

3.73 is the best compromise, that and working on your driving style.

thanks, ill put some more effort in my footwork and see how I go

4 speed auto ba xr6 turbo is 3.45. Six speed manual is 3.73.

Anyone try 4.11 - does it work with the turbo engine or would it limit boost build up?

4.09 is the closet you'll get in the gear sets for these diffs (although most sell these as 4.11) I had them in my old ute. After swapping out the 4spd Auto for a T56 the 3.43 was waaaaaaaaay to tall. Could do 80+kph in first. I changed the ratios to 4.09. Was laggier off the line than the 3.43 and would light the tires once it came on. Roll's at speed where fantastic though. A touch of brake to load it up and off she would go.

IMHO 3.73 is the spot on ratio for the T56. Especially if you can find a T56 from an F6/GT that has the closer 2/3/4 ratios.

I noticed no difference swapping to 4.11's from the 3.73's. I did order 3.73's when I rebuilt my diff, they sent the wrong ones but I honestly can't tell the difference

4.09 is the closet you'll get in the gear sets for these diffs (although most sell these as 4.11) I had them in my old ute. After swapping out the 4spd Auto for a T56 the 3.43 was waaaaaaaaay to tall. Could do 80+kph in first. I changed the ratios to 4.09. Was laggier off the line than the 3.43 and would light the tires once it came on. Roll's at speed where fantastic though. A touch of brake to load it up and off she would go.

IMHO 3.73 is the spot on ratio for the T56. Especially if you can find a T56 from an F6/GT that has the closer 2/3/4 ratios.

I'll look into getting 3.73's thrown in

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