Got to drive my buddy's D4 S8

[rtmeikle]

That car is NICE. I don't think I'd like to drive something that big on a daily basis, but the interior is beautiful. Tons of carbon fiber and brushed aluminum, ventilated massaging seats, and loaded with every feature you can imagine.

And the thing can MOVE. Twin-turbo V8- it is deceptively fast. We did a couple rolls together, one from about 25, and one from about 50, and he comfortably walked on my Stage II both times.

Anyone had any experience with one of these?

[KRp220]

saw a tuned A8 run consistent 11.8 sec 1/4 mile times at the dragway one night. i can only imagine how quick the S8 is

[wangshuo1989]

That thing has a RS7 engine right? I think B8 S4 has no way to touch that performance

[rtmeikle]

Yep, I think it's the same engine, just tuned differently. It's a beast.

[Morritse]

That thing has a RS7 engine right? I think B8 S4 has no way to touch that performance

Ehh, not too sure about that. A lot of our s4s have a better power to weight ratio than the s8. They do a 3.3s 0-60 and 11.6 1/4. A lot of peoples' s4's on here are quicker.

[rtmeikle]

Ehh, not too sure about that. A lot of our s4s have a better power to weight ratio than the s8. They do a 3.3s 0-60 and 11.6 1/4. A lot of peoples' s4's on here are quicker.

Yeah, there are definitely some fast S4s on here (WAY faster than mine.) But from a roll, where weight is less of a factor than HP, I wonder if even the fastest could compete with the S8. I was impressed.

[Morritse]

Yeah, there are definitely some fast S4s on here (WAY faster than mine.) But from a roll, where weight is less of a factor than HP, I wonder if even the fastest could compete with the S8. I was impressed.

I think so. People here have over 600 crank. Our powerbrand is probably a bit wider too.

Weight is actually more of a factor from a roll. It helps you from a dig (more traction)
F=MA

[endy1]

Here is a good video to compare:
Same engine as the RS6 but weights more, so a bit slower.

[rtmeikle]

Very cool video- thanks for sharing. A guy down the street has a V10 R8. I gotta' find a chance to introduce myself!

[kevinz]

sigh...someday. those headlights are my favorite ever.

[Bartlett]

I think so. People here have over 600 crank. Our powerbrand is probably a bit wider too.

Weight is actually more of a factor from a roll. It helps you from a dig (more traction)
F=MA

Who has over 600 crank? :o

[hilmar2k]

I think so. People here have over 600 crank. Our powerbrand is probably a bit wider too.

Weight is actually more of a factor from a roll. It helps you from a dig (more traction)
F=MA

You have that completely backwards. Weight has much more of a negative effect from a dig. Once moving, it's much more about power.

[rtmeikle]

You have that completely backwards. Weight has much more of a negative effect from a dig. Once moving, it's much more about power.

Yeah, that's why I didn't bother replying.

[Morritse]

You have that completely backwards. Weight has much more of a negative effect from a dig. Once moving, it's much more about power.

I don't think so. It's pretty basic physics. Acceleration is in essence power to weight ratio. The large exceptions are when traction or drag is the limiting factor.

At a given power to weight ratio, the car with more traction should accelerate faster (everything else being the same). And since traction is a function of friction is a function of weight....

[hilmar2k]

I don't think so. It's pretty basic physics. Acceleration is in essence power to weight ratio. The large exceptions are when traction or drag is the limiting factor.

At a given power to weight ratio, the car with more traction should accelerate faster (everything else being the same). And since traction is a function of friction is a function of weight....

You are looking at traction in a vacuum, which you can't. The additional traction that comes form the extra weight is not sufficient to overcome the extra power required to move that extra weight.

As long as you're traction limited (initial hard acceleration), lighter cars of the same power to weight will accelerate faster. Once you get beyond that, the cars with the higher power will accelerate faster, since the aerodynamic drag will be a much lower percentage of the car's power (since the drag will be similar with both cars). That's why lighter cars win off the line, and high power cars run them down at speed.

[sacandagaD]

This thread is over.....

[doughboy17]

You are looking at traction in a vacuum, which you can't. The additional traction that comes form the extra weight is not sufficient to overcome the extra power required to move that extra weight.

As long as you're traction limited (initial hard acceleration), lighter cars of the same power to weight will accelerate faster. Once you get beyond that, the cars with the higher power will accelerate faster, since the aerodynamic drag will be a much lower percentage of the car's power (since the drag will be similar with both cars). That's why lighter cars win off the line, and high power cars run them down at speed.

I work and hang out with a number of engineers. Stuff like this is gold to me!

[Morritse]

This thread is over.....

Sigh. I guess it's time to stop. Even though I disagree :(

The one thing I will say though. There's no point in talking about weight, or power. If 2 cars have the same power to weight ratio. The one with more traction will win. Weight doesn't matter. Power doesn't matter. Power/weight matters.

[sacandagaD]

Sigh. I guess it's time to stop. Even though I disagree :(

The one thing I will say though. There's no point in talking about weight, or power. If 2 cars have the same power to weight ratio. The one with more traction will win. Weight doesn't matter. Power doesn't matter. Power/weight matters.

One thing for sure, physics left the S8 discussion in the dust in a hurry, lol!

[hilmar2k]

One thing for sure, physics left the S8 discussion in the dust in a hurry, lol!

That's because physics, while heavier, has more power. The S8 won the thread initially, but physics caught it and outran it.

[fs454]

I can't do big cars. BMW gave me a twin-turbo V8 equipped loaner once while I had my 135i in for service and the same driving style I had with my 1-series burned through the giant 22 gallon fuel tank in hours. You could watch the fuel gauge move after one hard onramp launch. That thing was so expensive to run that I barely drove it.

[kristokes]

Moved into the A8/S8 section.

[q5 dave]

Can't imagine an S8. The 4.0T in our a8l is epic, and it's stock.

I thought my stg2 3.0 q5 was fast. ha.

[Phrost]

I really want to drive (or ride in) an S8. I've had a very tuned B8 S4 for 8 years now, yes very quick, but I could only hit mid 12's in the 1/4mi (mainly due to weak clutch). D4 A8 is supposed to run that stock, and I just had APR flashed on my 4.0T last week...

Overall the A8 feels quicker, but it's also huge/heavy and automatic. Just such a different feeling in the S4 having a 6speed manual and a smaller car

Now if only someone would make intake/exhaust for the A8 so it would sound better!

[PhillyVance]

Ehh, not too sure about that. A lot of our s4s have a better power to weight ratio than the s8. They do a 3.3s 0-60 and 11.6 1/4. A lot of peoples' s4's on here are quicker.

You are saying that someone's S4 would keep up with an S8? Stock no way, and tuned no way in hell. The S8 horsepower is underrated at 520 at the wheels. The S8 Plus is even higher. And for that video, I am not sure where it's taken but the RS6 is not sold in the US, or I would have an RS6. You cannot compare a stock S8 with tuned anything, I am positive there are S4's that have more money in them than my S8 cost me.

[m4xm1l10n]

Stock S4’s with 600 crank ? Lol

Crank is a thing of the past ...
My S8 is aight, it moves for 4635lbs including me .