Dragonslayer

dgbaudiphile

Fairly significant differences between high output variant 4.0T (S8 vs. A8/S6/S7), most of which relate to higher boost (cooling and compression)
1. Different piston (crown design)
2. Lower compression ratio in S8, accommodating higher boost
3. Larger diameter main bearing
4. A difference in crankshaft material
5. Addition of an auxiliary oil cooler (two vs. one oil coolers)
6. Larger main radiator
7. Dual-branch air intake (one for each bank/turbo)
8. Valve timing (camshaft profile) difference
9. Larger turbo compressor wheels

For these reasons, unless you go nuts with a custom overhaul, a Stage III A8 (if will ever exist) will still not outperform the S8 Stage 1 (or II) - the reason APR hasn't pushed towards Stage III (other than there's little/no demand) is cooling. When you start pumping out any more power than you're currently producing, heat becomes a big issue. I'm all for achieving the unachievable but you'll struggle to do so economically. Yes, we went to the moon but we spared no cost. I can rattle off a few custom shops who, for $50+ grand, will put 1200 hp in your A8. You can probably get it to 220!

As an aside - have you upgraded your brakes and tires? Most tires aren't rated to handle those speeds for any length of time (particularly with a heavy car like the D4).

Dragonslayer

Dragonslayer

dgbaudiphile

Good luck and let us know how APR responds. I wasn't being literal in terms of having first-hand experiences with these shops but there are a few out there that focus on Audi and Lambo and 1/2-mile runs. They are out there with packages to modify your car from - $40-$100k+. Sky is the limit as long as money is no object.

Here's an example...

https://www.motor1.com/news/178564/a...lf-mile-video/

Dragonslayer

APR already told me to pound sand, respectfully of course.

Silly Rabbit Motorsport | Audi S4, RS4, RS6 | Porsche Turbo Upgrade

if you want something weird done, go to Vegas!

j.ms

My new turbos are currently on the way from them. Stage 3 S8 coming soon.

chris355

Ritz

Picking up a 2015-ish S8 and adding APR stage II fixin's is a pretty good value if you want a comfy autobahn cruiser that can absolutely spank almost anything on the road and still be reliable and not likely to spray pieces of connecting rod all over the highway. You're talking 50K or so for the car and another 4k in upgrades to get supercar performance on an Acura budget. You can play similar tricks with the A8, but you won't get that extra 100 or so HP that the more tank-like bottom end of the S8 gets you.

Best,

Ritz

It's unfortunate that their website is so dysfunctional. I've been trying to get info on what they have for Audi cars for 10 minutes and get a spinning icon.
Actually, it's more like someone playing a xylophone...