SR71 wrote:I reckon 100 gear shifts around the Ring?
Even if each S-tronic shift is only 1/10 sec faster than a manual shift in the RS4, there is your 10 secs...
Hmm, yeah, never thought of that.....
SR71 wrote:The GTR is ~1700kg and runs sub 7.30 with (ostensibly) ~480hp so the extra 60hp is worth ~30 secs on the RS4!
Weight + trick diff = performance
I would suggest it's a bit more than a trick diff and 60hp that makes the GTR 30 seconds quicker than the RS4 (despite the GTR's weight as you mention). In particular the 434lb ft torque the blown engine creates compared to the 317 of the audi. The main point being the GTR chassis is a bespoke design rather than one robbed / adapted from another VAG platform.
SR71 wrote:I predict somewhere between 7:50-7:55.
That would be amazing.

Not sure where you guys get your times from but this is from supercars.net. 10 seconds quicker than stippler's 7.58 would put it ahead of some pretty quick cars. Just can't see it - GT3 RS fast?! Don't want to appear negative here either. I genuinely hope it is as quick as you are expecting.
35. Lamborghini Gallardo Superleggera 7:46 159 ´07 530 / 1520 Auto (Italy)
36. Jaguar XJ220 7:46.37 159 ´92 549 / 1555 John Nielsen
37. Ferrari 599 GTB Fiorano 7:47 159 ´06 620 / 1748 Sport Auto
38. Porsche 997 GT3 RS 7:48 158 ´06 415 / 1375 Sport Auto
39. Lamborghini Murcielago 7:50 158 ´02 580 / 1800 Sport Auto
40. BMW M3 CSL (E46) 7:50 158 ´03 360 / 1385 Sport Auto
41. Porsche 997 Carrera S (2008 facelift) 7:50 158 ´08 385 / 1425
42. Mercedes SL65 AMG Black Series 7:51 157 ´09 670 / 1870 Sport Auto 05/2009
43. Lamborghini Gallardo 7:52 157 ´03 500 / 1613 Sport Auto
44. Ford GT 7:52 157 ´04 550 / 1538 Sport Auto
45. Lamborghini Gallardo LP560-4 7:52 157 ´08 560 / 1530 sportauto
46. Mercedes CLK DTM 7:54 156 ´04 582 / 1678 Sport Auto
47. Porsche 996 GT3 late 7:54 156 ´03 380 / 1380 Sport Auto
48. Ferrari F430 7:55 156 ´05 489 / 1450 Sport Auto
49. Porsche 996 Turbo 7:56 156 ´00 420 / 1540 Sport Auto
50. Ferrari 360 CS 7:56 156 ´03 425 / 1280 sport auto 02/2004
51. Chevrolet Corvette C5Z06 '02-'04 7:56 156 ´01 411 / 1414 Dave Hill
52. Porsche Panamera Sport Chrono Turbo 7:56 156 ´09 500 / 1974 Walter Roehrl (AutoB
53. Porsche Panamera Turbo 7:56.0 156 ´09 500 / 1870 Walter Röhrl
54. Porsche 996 GT3 early 7:56.33 156 ´99 360 / 1350 Walter Rohl
55. Honda NSX-R 7:56.733 156 ´02 280 / 1270 Motoharu "Gan-san" K
56. Lamborghini Gallardo LP560-4 7:57.46 (full lap) 155 ´08 560 / 1530 AutoBild sportscars
57. Audi RS4 (B7) 7:58 155 ´05 420 / 1720 Frank Stippler