Who Knows About Rear Ends?

[VetteTax]

Am undecided about which rear axle I should go with? 2.56 which is standard with the 6-spd Auto vs. a 2.73 "Performance" axle on my '08 w/ F55 Magnetic Selective Ride. I still have a chance to change my order. I intend to keep my new baby stock (as I'm married now) and she'll still be my daily driver. Pricing is still unavailable.

[Eddie44]

Am undecided about which rear axle I should go with? 2.56 which is standard with the 6-spd Auto vs. a 2.73 "Performance" axle on my '08 w/ F55 Magnetic Selective Ride. I still have a chance to change my order. I intend to keep my new baby stock (as I'm married now) and she'll still be my daily driver. Pricing is still unavailable.

I'm not sure but I believe the 2.73 came with the Z51 package that I got on mine. It's great and I personally wouldn't see why anyone would go with the 2.56, short of a light gas mileage.

[Ted Y]

I'm pretty sure we had this discussion a bit ago. You have to look at overall gear ratios, not just the differential one. If someone scrounges up the link, I believe the A6 has a very high ratio (short) first gear, so coupled to the 2.73, produces a very fast revving first gear. Only a transmission with a low ratio (tall) first gear would need a high ratio diff.

I'd say go with the 2.73 like Eddie said.

[Grayeagle]

From what I have read, the new Vette's are all going to have a *nice* launch gear in first, much better than our C-5's have, even with the 3.15's, along with the great cruising gear in 6th.

The 'performance' gear will offer just a bit more zip off the line .. as usual

-Frank

[Desertdawg]

Dan, is this the thread you are looking for??????

[ELESWUN]

3.42s FTW

[Bob]

Call Alan Hall at the Gear Shop (602) 437-1476. Best in town (and my mountain biking buddy).......

[Purdue]

I recommend going with the 2.73 perf option. I suspect it will be a very popular option! Wish they offered it in the 2006 and 2007 models

Here are some ratio to look at when it comes to rear end gearing. I posted a month or so ago.

Note the gearing for the A6 w/ 2.73 will be much stronger than the non Z-51 M6 w/ 3.42’s in 1st and 2nd gear.

2008 C6 A6 2.73

4.03 11.00

2.36 6.44

1.53 4.18

1.15 3.14

0.85 2.32

0.67 1.83

2006/2007 C6 A6 2.56

4.03 10.32

2.36 6.04

1.53 3.92

1.15 2.94

0.85 2.18

0.67 1.72

2005 C6 A4 3.15

3.06 9.64

1.63 5.13

1.00 3.15

0.70 2.21

2005 C6 A4 2.73

3.06 8.35

1.63 4.45

1.00 2.73

0.70 1.91

2005-08 C6 M6 3.42

2.66 9.10

1.78 6.09

1.30 4.45

1.00 3.42

0.74 2.53

0.50 1.71

2005-08 M6 Z51 3.42

2.97 10.16

2.07 7.08

1.43 4.89

1.00 3.42

0.71 2.43

0.57 1.95

[Purdue]

Am undecided about which rear axle I should go with? 2.56 which is standard with the 6-spd Auto vs. a 2.73 "Performance" axle on my '08 w/ F55 Magnetic Selective Ride. I still have a chance to change my order. I intend to keep my new baby stock (as I'm married now) and she'll still be my daily driver. Pricing is still unavailable.

I'm not sure but I believe the 2.73 came with the Z51 package that I got on mine. It's great and I personally wouldn't see why anyone would go with the 2.56, short of a light gas mileage.

The 2006 and 2007 non Z51 and Z51 A6's had the same 2.56 ratio while the M6 Z51's received a different gear ratio compared to the non Z-51 M6's.

I agree ordering a 2008 A6 the 2.73 axle should be a no brainer. Word is it can be purchased as a stand alone or if you opt for the Z51 package it comes standard.