Surprised a newer A8

[Cmnair]

At a light three lanes merging into two. The A8 (twin turbo V8) came flying up on third lane (there was nobody behind me). Open road for about half a mile in front of us. The light turns green and we floor it and he couldn’t catch up. May have taken him by surprise because he probably thought “old Audi”. I think those cars are faster (he may not have been on it in the beginning). He was pacing me a bit and then gave a thumbs up before turning off.

Dont usually do this but I thought this was a good opportunity to see how the old girl held up vs newer cars with similar power.

Somewhat similar experience with newer S550... he was surprised too.

[DHall1]

Remember the thread a bit back about how "slow" these old RS6s were.

I called BS and the $hit storm started.

Lol

if you don't maintain and keep up on the tune of these cars then you will have a big turd.

If you keep up on the tune? Well we see what can happen.

My beater RS6 w115k clicked off 12.50s with no hard launches.

[Cmnair]

I was pleasantly surprised too. I didn’t launch either... just rolled of idle and then floored it progressively. The car moved like a freight train. I know we can’t launch as well as these newer cars with launch control engine management gizmos but once it gets moving it is such a rush.

[ben916]

.I know we can’t launch as well as these newer cars with launch control engine management gizmos but once it gets moving it is such a rush.

Rat Duck Goose - as Patrick would say...

[Aronis]

I drove an A8L for a few years, it was very quick, don't think my RS6 was faster (stock).

Mike

[DHall1]

As as noted by cmnair above. He has both the A8 and S550 covered.

If his RS6 is running properly that would be the case.

I have both those vehicles easily covered by my RS6s.


I drove an A8L for a few years, it was very quick, don't think my RS6 was faster (stock).

Mike

[Bigglezworth]

A good tune and regular maintenance and only a select few cars will out run you. I ran a douche bag driving a new ZL1 Camaro and he was astonished that he only barely eeked out a car length after a full half minute sprint. Guy was utterly dumfounded on what just happened. Yes, before you ask - he had a mullet & moustache..... lol

[lswing]

Figure you're at least 20% slower not tuned...

Mike, you need a tune! And then you can get a new transmission! Or not if you're careful and timely with shifting...

[Aronis]

Figure you're at least 20% slower not tuned...

Mike, you need a tune! And then you can get a new transmission! Or not if you're careful and timely with shifting...

My RS6 is stock! My A8L was stock. My M2 is stock. :)


I don't want to buy another transmission. I have not even gotten my parasitic current drain fixed yet! The car is sitting in the garage with the snows on but no love!

Mike

[RSSIK]

I also have a 2013 a8L 4.0T and ran it stock and got a 12.2.. after doing a simplestage 1+ tune I ran an 11.8. Definitely faster than the old girls and even though its a bigger car it feels much more nimble than the rs6

[GreggPDX]

I also have a 2013 a8L 4.0T and ran it stock and got a 12.2.. after doing a simplestage 1+ tune I ran an 11.8. Definitely faster than the old girls and even though its a bigger car it feels much more nimble than the rs6

Damn, that's quick. Do you remember your trap speeds?

I wonder how much the newer transmission helps too...

[Bigglezworth]

Numbers are entirely associated with gearing of the transmission and differentials. Back in the day (gawd I sound old), the age old trick to improve acceleration times was to swap the gears in the rear end. If one were to alter the gearing of the C5 RS6 you can get it to accelerate quicker also. Clearly we can't alter the internal gearing of the ZF auto, but we certainly could change the gearing in the differentials. Not aware of anyone having done this though?

[DHall1]

As that would be a sure fire way to snap that trans input shaft.

Im happy I have what I have

[Bigglezworth]

As that would be a sure fire way to snap that trans input shaft.

Im happy I have what I haveI don't know that the difference in gearing would have that much of an affect. The front and rear differential RS6 gearing is 3.197

The base ZF tranny gearing is:
1st: 3.571
2nd: 2.200
3rd: 1.505
4th: 1.000
5th: 0.804

Final gearing then is:
1st: 11.412
2nd: 7.033
3rd: 4.811
4th: 3.197
5th: 2.570

The S6 has final differential gearing of 4.111. “IF” the parts could be swapped, I might in fact give it a go. That would give a staggering 1st gear of 14.680 – albeit at the cost of your 5th gear top-out.
So, to my point, the new ZF 8spd transmissions have an additional 3 gears which assist in getting you a steeper 1st gear (launch) and 8th gear for some long legs. The new RS7 as a reference has a base first gear ratio of 4.71 and a differential gearing of 3.08. That’s a final gearing of 1st: 14.507 which is just a tad smaller than the above.

Entirely about gearing as you can see. Yes, with only 5 gears, you compromise upper for lower. I don’t tend to drive 280+ all that often, so I wouldn’t mind having more fun with gearing that helps acceleration even more. I think I need to research the swapping of the front diff a bit more now.... :) To my benefit, I have both a C5 RS6 and S6 tip sitting in my garage collecting dust. Time to disassemble the diffs and check things out with micrometers.

[nubcake]

The front and rear differential RS6 gearing is 3.197

????
Talking C5? It's 4.111.

[Bigglezworth]

????
Talking C5? It's 4.111.
Well, I guess that Wikipedia has it wrong then....?

18373

[nubcake]

Actually, it's a bit trickier.
Rear diff is 4.11, but final drive ends up being 3.19 due to internal gearing of the transfer case.
So what I'm trying to say is - you can't just take front and rear diff from the S6 and plug it into the RS6 to get different gearing.
Check this table:
18374

[Bigglezworth]

Right Spur gears that are a slight multiplier. Wiki would benefit from adjusting how they describe things by not stating the value as a differential value, and to improve the inclusion of the spur gears. Anyway, the 30:11 front ring & pinion is different than the rear 37:9 ring & pinion. My observation above still remains the same in that I would wonder about revising the ring and pinions in the two differentials.

[G2]

Increasing power and torque effectively increases the numerical gear ratio value when compared to a stock engine. I call it the "cheater" method.

Much as I despite my Revo tune it sure hits hard on the torque.

Should be going head to head with a 550hp Jag next week or two. I hope it's a cold day.....

I am now using Amsoil Octane Boost with each tank. Bought a case last week. Impressive stuff- normally only use it during the summer. It's like my boost is back to where it was before lowering. Might try 2 bottles when the Jag is ready to play...:revs:

[G2]

I believe one of the advantages of the 5spd gearing is it's very well suited once rolling. Would predict if gearing was reduced (higher #'s) too much the car would be significantly slower. Unless it had more cogs to grab to keep the engine loaded.

For a drag strip queen would certainly focus on getting the car launched. That's how the new cars are so fast off the line. Short gearing for impressive 0-60's. But at speed the Ol' C5 walks them or is in striking distance.

Drove a 650hp Shelby (595 whp) I worked on years ago and it didn't feel much faster than the RS.

And after driving a MT6 RS6 conversion was a bit let down. Stilly short 1st gear. Car was down on power so was like driving a NA S6. Thinking if a newer Autobox would fit (someone chime in?) that would be the ticket. D

[Cmnair]

Agree Gary... at speed this car is pretty impressive