D3AeighT

Has anyone explored installing the S8 exhaust system and tail pipes on an A8?

In speaking with a parts guy at a local Audi dealer, he said it would fit and boost HP power significantly more so than a new chip. Price around $500. Would ECU have to be re-programmed, etc. Would warranty be effected?

icsamerica

I went through this already and according to my research at the dealer parts counter, The S8 and short wheel base A8 exhaust systems have the same part number. I've owned both a 2001 A8 and 2001 S8 and I can tell you they both sound the same.

D3AeighT

OK, what about the questions regarding increased HP? How many more horses? ECU change required if HP increases.

Mikes97A8

I there shouldn't be any computer or ECU changes required as long as the new exhaust system has the same emissions (i.e., cataletic converters). Since icsamerica says the S8 and A8's exhaust has the same part number I would guess there is no difference.

ryoung

"Where the V8 in the A8 is muted and reserved; the S8's engine is rough, with a deep rumble being emitted from the exhaust." Jon Linkov

What???? Did this S8 have a hole in the muffler and a dead coil pack? I can't hear the exhaust on my S8 unless I put my ear near the tailpipe, and I think I can balance a coin on it's edge on the motor cover.

John, I agree with you - no difference between the A8 and S8 exhaust. I can't imagine what car Linkov was reviewing (or thinking).

D3AeighT

How can they be the same part number when they supposedly offer increased air flow to give the S8 additonal horsepower? I know it's the same distance since we dealing with the same body length, etc vs the stretch L.

Can anyone confirm that putting a S8 exhaust system and tail pipe assembly on an A8 gives additional horsepower (HP)? If it costs around $500 bucks to replace the A8 exhaust with the S8 and lets say you get 25 more HP and better looking brushed aluminum tips (that some mail order wants you to pay $150 buck for), sounds like a pretty good deal to go with the standard Audi S8 exhaust system and put it on the A8.

April/V - you must have the answer?

icsamerica

I've seen this "Exhaust rumble" in print a few times, notably Motor Trend states Audi changed the exhaust system to get more HP. We'll we know it's not true and their credibility is suspect. I think their doing these reports in front of the PC not at the wheel.

D3AeighT

with increasd HP since in reality more noise more air throughput, etc., and you are saying there is "absolutely" no increase in S8 exhaust sounds over the A8.

But can you answer the answer the "real" question at hand? Does the S8 exhaust system offer increased HP or not? What were all the variables that gives the S8 60 more HP? Is the exhaust one of them and if so how may ponies got added? from the exhaust?

Since you already covered every issue regarding this subject point me to the weblink and we can leave it there.

As I noted, a parts guy at a local Audi dealer, sort of indicated to me there would be increase HP by putting S8 exhaust system on an A8, for about $500 bucks. And I don't think he was just trying to sell me a new exhaust when not needed.

ryoung

... perhaps the cats are different, but the S8 exhaust by itself is almost certainly not worth the money for expected HP gains. Someone would need to run dyno tests, though, to confirm. The S8 doesn't even have equal length primary exhaust runners, which you'd expect to see to get max hp numbers.

I have no cam specs for either car, but believe that increased lift and duration on the S8's cams probably account for most of the difference, and I wouldn't be surprised if the variable length intake runner manifold "shortens" the runners at different rpm's also.

Note also that the A8 produces 310 hp @6200 rpm; the S8, 360 hp @ 7000 rpm. Does either the Auto trans or Tip on an A8 even allow you above 6200? Probably not.

bassp01

Why waste money on an S8 system when for $300 you can get a new sport muffler with great looking chrome tailpipes from LLtek. I have a second generation sport muffler I am installing shortly. The first one was simply too noisy (off idle) and resonated too much. While I like the S8 muffler and tips, this new sport exhaust makes the S8 tips look puny.As far as performance, the sport muffler may increase the power very slightly at higher rpm's but you don't feel a big power difference, just the rumble of the exhaust.