I have a 2010 drive train with a 6l80e.
I want to swap out my bad the diff with a ZR1 diff. I spoke to subfloor@centurytrans , I thought he was running the ZR1, but he is ruunning the z06 with the A6. He said the Z06 bolts right up! I guess I should price the two units(only if they both will bolt on)
I hear the diff will mount a little further back, but will the 6l80e bolt right up? output shaft on the tranny correct? Anyone with experience on the this swap would be great!

 

I've worked on 2 cars with this ZO6 diff conversion.1 05 car and an 09 car.the 09 car bolted right up as it has 30 spline output shaft in transmission and the 05 car required a 30 spline output shaft installed in trany along with adapter plate to bolt trany to diff.05 car also needed holes in rear cradle slotted 1/4'' for diff.the ZR1 diff as far as I know are identical in dimensions and will bolt right up

 

Great! I just spoke to RPM and they are building a ZR1 diff for me. It will mount right up to the 6L80e. They also build the braces for $425 on a custom order bases.

 

The Z06 diff bolts right up to the A6, without any need for an adaptor. As far as I know, the ZR1 should as well.
The splines in the A6 and Z06 diffs are identical, but due to the larger ring gear and housing, the output shaft of A6 does not engage fully into the splines in the pinion of the Z06 diff, but I've never heard of an output shaft breaking yet on one yet, except when they're run without a brace and the transmission and diff tries to separate at the top, breaking the ears off the diff and bending the output shaft until it snaps. If subfloor isn't breaking them running 1.3x 60' times with the front wheels dangling off the line, I doubt that they can break.
The only problem with the Z diff is that you're limited to one gear ratio: 3.42:1.

 

I have a '11 GS A6 with a ZR1 diff bolts rite up no adapter needed is the best diff is 10 lbs heavier the case itself is beefier and the ears that brake off on the ZO6 diff are re enforced on the ZR diff.

As previously mentioned else where on here you need to slot the rear diff mount holes 10mm tours the back.

If you want to use the diff cooler on the ZR diff you will have to modify the diff cradle I have pictures if you need em PM email.

 

That isn't accurate, I have a RPM Z06 diff installed in my '05 with a 3.90:1 gear. Perfect gear to compliment base/Z06 transmission gearing

 

I've never been able to find anyone that made gears for the Z06 diff. Was unaware that RPM has other gearing available. I'll have to give them a call. I would love to be able to get a higher ratio ring and pinion for my stock Z06 diff.
3.90 gearing may be the ideal ratio for the base/Z06 trans, but it would be way too much gear for the 4.02 first gear in the 6L80, IMHO.

 

1. 

That would be an awfully short 1st gear lol

 

I agree for must 3.90 diff gear and 4.03 first is a bit too tall but not for all with 7,200 shift rpms and 28" tires 14.1 compression 3.90 is just great for a 1/4 mile track then for 1/8 mile track 4.10 of course maybe you will not agree with me unless you drive the car or see it in action, sure this is uncharted territory for 99% of this forum population but not for all.

Few will know enough to have this much fun with stock block and no broken piston ring land and even less will dare.

 

Are you saying that you're running a 3.90 axle ratio with a 6L80??
What 28" tire are you running, and did you have to do anything to get it to fit?
I have a set of so-called 28" M&H (325/45/17) radials as well, but they actually only measure 27.25" diameter on a 17x11 wheel. I would bet a good sum of money that a true 28" would rub pretty hard in a stock C6 wheelwell, especially if it's a racing tire that grows at speed.
My car shifts at 6900-7000 too, and I'm sure I could make it shift at 7200 without breaking anything, but I wouldn't think of putting a 3.90 gear in it, because when I calculate the gearing vs. tire height, that would definitely cause a shift into 5th before the end of the 1/4 mile, even at that RPM.
With the 3.42s, my car shifts 4-5 right around 140mph, which is fine for me. However, on the street, which is where most of us drive, it doesn't hook for **** in first gear, but that's probably because I don't know what I'm doing. So for me, a 3.90 gear, let alone a 4.10 would just be a waste of time. I would venture to say that it would be the same for the other 99% of the "unenlightened" members of this forum too.
Gearing is like everything else, the ideal depends on what you're doing, what power you're making and where you're making that power, so you can't expect the optimum gear for a N/A car that runs mid 10s at like 132 to be the best gear for a FI or nitroused car that will run a second quicker and 10 miles an hour faster. This is especially true when you factor in the low first gear in a 6L80/90 trans. Nitroused and boosted cars make lots of low end torque and horsepower, so they will obviously be harder to hook than a N/A setup. That's the simple reason they don't need the torque multiplication of a lower first gear as much as an N/A car.
There's nothing here that's new. It's all maths and applied physics at the end of the day, not black magic.
I don't get what a stock block and the absence of broken ring lands have to do with a discussion about gearing, or compression, for that matter. But, I suppose, such knowledge is reserved to the realm of luminaries such as yourself.

 

Wow first broken ring land for the fI victims lead to it as best power adder for stock ls engine.

My car has a 3.42 gear in it just that my combo would be rite at home with 28" tires (in my drag pack now) and taller gears, your set up may not be able to go there as you are not in same rpm extension.

My statement there's no need for fI and it's consecuences to stock block when is possible to have a killer performer with out broken pistons ring lands.

Any one reading the what do I do now treads started almost every week by poor fI victims will undertand making the car fast should not have to destroy it.

Finally first gear in my car on the street is lethal as is at the track but then is just as lethal in second and third all these are areas of performance to be worked and is just as important an area to work on as is making power.

The corvette suspension is great as design but not as tuned so all I'm using of it is the control arms and these are not stock.

So to get power increased and better gears just to go explain how it all useless? not me.

 

Us poor FI people have no clue ? I guess we are all stupid. You say 3.90's would be great, but haven't even tried that combo? First gear would be more than useless with that high a gear, boosted or not.

Please let us know how it works out when you actually run that combo.

 

the 3.90 gear installed in your Z06 differential is the smaller base ring and pinion setup so that you have a choice of axle ratio's.you no longer have the physically larger Z06 ring and pinion in your Z06 case

 

Don't waste your time Jody, we are not worthy, are we are clearly in that lower 99 percentile group of idiots of CF that he's complaining about. The most amazing thing is the audacity of someone who readily engages in argument in a language that has clearly not yet been properly learned, let alone mastered...
Apologies to the OP. It wasn't my intent to engage anyone in argument here. Was just trying to give some useful input.

 

i have a rpm 3.90 in my c6z lsx/ysi setup and dont have any issues. leaves like bat out of hell.

 

Is your car an A6 or an M6?
The 3.90 should be a good gear for an FI/M6 Vette, since you'll have a much taller (lower numerical)1st gear than an A6.

 

 

RPM just delivered the ZR1 case with 3.42 and brace kit for A6.
Compared to the base diff it is beefy!

 

Congrats man that upgrade looks great you'll will appreciate the extra go in all gears.

I weight mine and was 10 lbs heavier than the grand sport 2.73 diff by the way where did you find the girdle and did you get the pics...

 

I never received pics:-( Please try to resend if you can. I think you said you were having intermittent internet service at the time.
The braces were made by RPM to mate up to the 6L80e. Before I send the core back, I will weigh the two units. I feel the difference. The ZR1 unit has much thicker ribs and seems bigger on the sides. I’ll post pics after I get the tranny mated up with the bracing. It’s still being built right now.