Any differences in the Quattro system between the S and RS in b8/8.5 series?

[Yoda1]

Ok. So except for a slight tune, I know the the tranny in the rs5 and s4 is the same but how about the Quattro system?
Any knowledge is appreciated:)
Vance.

[snocat17]

Well, technically no, but the RS came standard with a Sports Differential that has torque vectoring. It was an option on the S5 and many decided to save the $1100.

[Ape Factory]

There are definite tuning differences and the rear differential is actually specific to the RS5 (has a different part number). I know the final drive is shorter on the RS5 version but I'm not sure if there are differences in say the number of clutch plates, lockup strategy, motor, etc...The RS uses it's brakes for the ESC and it's pretty non-invasive, especially in sport mode. The RS track is also wider.

Gearbox wise, they're all DL-501 gearboxes but there are internal differences and the RS box is more highly tuned delivering a higher rpm, quicker shifts, etc...
That gearbox is uses in the S6/S7 as well as all of the 4's and 5's. I think Oleg determined there were differences in the clutch packs between the S5 and the S6 with the S6 smaller clutch pack (there are two, a large and small clutch disk pack) having a larger diameter than the S5 but he'd have to chime in to verify.

[HazeMyth]

It was an option on the S5 and many decided to save the $1100.

I'm always shocked when I see them optioned without the sport diff, but then I remember that not everyone understands just how much it helps to alleviate understeer. The difference is night and day!

[Magowin]

I'm always shocked when I see them optioned without the sport diff, but then I remember that not everyone understands just how much it helps to alleviate understeer. The difference is night and day!

Yeah I made sure the Cab I got had it especially helps with that car due to heavier weight.

[superswiss]

Yes, there are differences in the quattro system. The B8 RS5 introduced the grown-gear center differential 6th generation quattro system with torque vectoring. The B8 S4/S5 has a torsion style center differential and no torque vectoring. By torque vectoring I'm referring to the brake based system that slows down the inner wheels around corners, not the sport differential. The sport differential as everybody knows was an option in the B8 S4/5.

Audi then retrofitted the quattro system from the RS5 to the B8.5 S4/5 S-tronic, but not the manual transmission version. The manual transmission B8.5 still has the torsion style center differential and no torque vectoring.

The grown gear center differential is now gone. Audi went back to a Torsion style self-locking center differential in all of their longitudinal platform models.

[Yoda1]

Sweet!! Thanks for the info all!

Good video superSwiss. Thank you!

The reason why I wanted to know is this one kid with his B8 S4 was convinced that we had the same tranny and Quattro system. He also thought that at 30 mph we will be on the same RPM because we have the same transmission LOL

[superswiss]

The reason why I wanted to know is this one kid with his B8 S4 was convinced that we had the same tranny and Quattro system. He also thought that at 30 mph we will be on the same RPM because we have the same transmission LOL

Haha...yeah, not even close. The RS5 has different gear ratios and final drive, because it's a high revving engine. It has more aggressive gearing given that the powerband is between 4k and 8.5k. The S4's powerband is at the other end of the spectrum down low and the gearing is taller. Lot of folks don't understand the importance of gearing. They also only look at the engine torque and forget that the transmission multiplies the torque before it goes to the rear wheels, which means a car that seems to have less engine torque than a comparable car can make more wheel torque than the other car just by using proper gearing as long as it has the power. It's also widely misunderstood that horsepower determines how fast a car can accelerate and not torque. If you have enough horsepower, you can always gear the car accordingly to make the necessary wheel torque.

EDIT: BTW, this concept is important to understand in order to drive either car properly. For example to drive as fast as possible you would generally be a gear lower in the RS5 than the S4, because the power is at top and you have all those revs. The S4 on the other hand runs out of steam around 5000 rpm, so you have to keep the revs lower in order to drive fast and you don't have a 8500 redline to wind out to.