whayes

Can the A6 transmission/differential on a base C6 be upgraded to the Z-51 performance axle ratio?

Has anyone done this? Cost?

revo1059

There is no performance axle as an option on the A6. If yo mean taking the rear from a MN6 Z51, I don't think anybody has done that yet due to programming issues. DTE is working on options for the A6 (there is a thread somewhere about it), but it is still in prototype phase.

BADC64GO

Yup

DTE Powertrain

Our custom 3.15 gear set is no longer in prototype, as we have a car here in the shop for the upgrade now, another one coming in, in just a few weeks and we're already building them in full production for our dealers.

Waveblaster785

Pricing??

ben dover

revo1059

How much for the part? What kind of programming is necessary to make this work?

DTE Powertrain

A .pdf file will be posted here by late tomorrow morning that outlines the differential menu of options and prices for this vehicle platform, using this unique gear set.

Additionally, as with any gear change performed on any car that is equipped with an automatic of some sort, there is always PCM/TCM calibration required after the upgrade to properly set shift points and transmission shifting strategies for correct vehicle operation. Your preferred tuner should know how to do this, as it's quite routine.

AP

There should be OEM option in 2008 ..

revo1059

So there is a method to program the A6's TCM? I thought this was still uncharted territory.

knkali

ttt

LS1LT1

True, allegedly (not quite etched in stone yet) there will be a 2.73 rear axle ratio option for the automatics.


Yes and no...some areas are still uncracked and other parameters are now easy to change.
In the future more tables/upgrades to the tuning software are coming though.

knkali

I thought most guys on this board felt the 3.15 was too much for the A6 and the 2.73 is the way to go.

shurite44

Not me, when available if ever I am going with a 3.42. I have looked at the different speeds it would shift at WOT and that is what I am looking for.

LS1LT1

They do, but if you want some serious gains you've got to step up.


If changing gears in the A6 I would go with a 3.42 or at the least, a 3.15...getting 2.73s from the factory is nice and all but if you're going through the expense to upgrade you may as well make it really count.
If this new optional gear for 2008 is a reality then it might still be smarter for those planning on going with 3.15s/3.42s anyway to just pass on the option (likely going to be in the $400.00-$500.00 range and/or tied into the $1700.00 Z51 package) and apply that cash in getting the gear they want later on.
Unless of course you get a better/easier to modify carrier with that axle ratio option like in the past.

knkali

what are the calculated shift points with the 3.15? Wouldnt 1st gear really cease to exist?

shurite44

http://mysite.verizon.net/foofoo2/c6/
Here you go, you can check out all the different ratio's on a A6 here.

shurite44

Stock 2.56 at 6200 rpms is 47 with a 3.42 the speed would be 35. That does not seem to make first unusable to me. To me if I am going to put the money into a mod I want serious performance change.

Sixth gear at 6500 rpms would be 221 mph with the 3.42 fifth gear is around 175 or so at 6500 rpms.

There would be one more shift in the qtr mile though, only bad part, but the increased acceleration in the first part of the track would more than make up for it. I bet you would gain .3 in the qtr, with a 2800-3600 stall TC you would get over a half a second with the combo.

knkali

I think the numbers are wrong.

3.15 gear set shows at 6500 rpm a 6th gear of 240. The stock gearing takes it to 180ish how can that be? I would expect a 3.15 to LOWR top speen not gain.

glennhl

3.42's would make the auto a great 4 speed in the quarter mile. You'll just have to make sure you have a good set of slicks on the back to hook up out of the hole. I agree, probably worth .3 and you could get another .3 with a decent converter.