B8.5 sport diff retrofit?

[mc8198]

Has this been done, or does anyone know if it's actually possible? I can't seem to find any substantial information anywhere...

[LYKUNO]

Never seen anything about it having been done, although with enough $$$$$, just about anything is possible. Did see this one thread that might give an idea of what's involved to do a retrofit. As many others have said, if you're not driving at 10/10ths most of the time, you should be able to live without it - it is still a great car, even without the sport diff. Others with and without the option, and those who've experienced both can chime in here.

[Sceanzo]

I had a non sport diff car before my current equipped one. I would choose with it every single time.

[DBFL]

I had a non sport diff car before my current equipped one. I would choose with it every single time.

Same here. I had a '14 without it, and now have a '16 with. I definitely notice the difference. If buying an S4 I strongly recommending getting it with the sports diff.

As for a retrofit, no clue. I'd guess that it would would be quite expensive.

[FlyS4]

Any info on this?

[LYKUNO]

Any info on this?

I suspect the OP decided not to pursue it further, or else we'd have seen a build thread. The link provided in post #2 had the following comments from an indy Audi repair shop owner:

"I've also driven B8S4's both with and without the torque-vectoring differential. It's definitely a nice option, but not one that will affect resale value more than a few hundred dollars 4 years down the road. ... While a retrofit is "technically" possible, the work involved would be immense, including removing, and disassembling the transmission. I doubt any dealer technician in the country has done that. The cars are so new that if there are any transmission problems, they're covered under warranty and sent back to Audi without ever opening it up. But again, when I say it's technically possible, this would mean that a VERY good independent Audi shop would take on the job. Labor would run somewhere in the 30 hour range, I would expect the sports diff to cost at least $3k from a dealer parts department, and then software coding it to the car might be impossible with the existing drivetrain computer in the car, so if an ECU retrofit is needed, that would also be extra. All told, easily an $8k retrofit that would net you maybe $500 extra on resale."

Of course, if someone could do the work themselves and obtain the required parts from a wrecked/parted out S4 inexpensively, it might be worth attempting. For anyone else, it's probably cheaper to sell the car without it and buy another one with it.

[mmm def]

I've owned both, they're both great.

[S4'ed]

Retrofitting the torque vectoring differential does not require the transmission to be opened. There are no changes to the transmission, just swap the rear diff, add the computer box and associated wiring, and then some module recoding (probably the abs/ traction control ecu). I have thought of doing this retrofit, but it is hard to find a salvage torque vectorial different, especially for a manual transmission S4.

[S4'ed]

There was a used low mileage sport diff on ebay for $400, but it had the wrong gear ratio for a manual transmission.

[FlyS4]

I would like to do it...Can someone give me exact parts i need? I have a 2014 S4 DSG. Is it only the control module, wiring, and rear diff?
Can anyone get part numbers?

[waxxonMTL]

Would love to drive a sport diff compared to mine. I'm willing to bet that on a stock car the difference could be felt, but when you take one without, do quality coilover, full billet insert/bushing mod, add swaybar, sticky tires, I bet the difference get less and less.

[FlyS4]

Would love to drive a sport diff compared to mine. I'm willing to bet that on a stock car the difference could be felt, but when you take one without, do quality coilover, full billet insert/bushing mod, add swaybar, sticky tires, I bet the difference get less and less.

I had Bilstein pss10 coilovers and honestly they weren't much better than my stock suspension. The difference was that billsteins were reacting faster to bumps and settling. Stock feels less responsive. Nonetheless i felt just as confident going 170 on stock shocks as on coilovers.

[waxxonMTL]

I had Bilstein pss10 coilovers and honestly they weren't much better than my stock suspension. The difference was that billsteins were reacting faster to bumps and settling. Stock feels less responsive. Nonetheless i felt just as confident going 170 on stock shocks as on coilovers.

well, a sport diff won't do any different if your accelerating/cruising at 170 than a ''reg'' diff. However, if you are talking about 170 in a curve, where a sport diff could shine more, and you don't feel more secure doing it with the pss10 compared to the oem suspension, I simply don't believe you lol. I don't get your point here.

[FlyS4]

well, a sport diff won't do any different if your accelerating/cruising at 170 than a ''reg'' diff. However, if you are talking about 170 in a curve, where a sport diff could shine more, and you don't feel more secure doing it with the pss10 compared to the oem suspension, I simply don't believe you lol. I don't get your point here.

Its only my opinion. As far as steering feel it wasnt any different with pss10's. The car did stick better in turns. If i was to do proper turn in and accelerate right out of the apex then god damn it stuck to the ground. More so than stock units. High speed on i95 isnt that much different. I dont beliave coilovers made much difference when set to the setting i am ok daily driving in. Maybe if i set them on full stiff and do some runs on the perfect road with no bumps I would imagine they would outperform stock suspension.

[S4'ed]

Forgot to add : a retrofit would also need different halfshafts, as the length is different than what's used with the standard differential (the sport diff is wider). I think the driveshaft length is the same.