spec sheet for the d3 s8
02-28-2004, 11:53 AM
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spec sheet for the d3 s8
the following is what would promprt me to upgrade to the d3 s8 (over and above the d3):
1) 420hp v8 or v10
2) 6-speed dsg-type auto
3) fold-down rear seats
4) mp3-capable audio system
5) full bluetooth integration
what have i missed?
1) 420hp v8 or v10
2) 6-speed dsg-type auto
3) fold-down rear seats
4) mp3-capable audio system
5) full bluetooth integration
what have i missed?
02-28-2004, 02:01 PM
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You'll be sorry you asked: Part 1, mechanical
A. Weight - lighter, lower, further back, unsprung, rotating, and polar moment of inertia:
Shedding weight is probably the best, if not the most glamorous, way to improve all aspects of the S8's performance -- acceleration, braking, and handling. The weight of the current D3 A8 is totally unacceptable.
Losing 10% of the car's weight is equivalent to adding 40 HP and improves braking, with both shorter stopping distances and reduced brake fade. Less weight also improves handling; the tires have less mass to turn into a new direction.
Lowering the center of gravity 10% is like increasing the track 6 inches; less weight is transferred laterally under cornering, suspension geometry is easier to control, and handling significantly improves. Also, less weight is transferred forward under braking. Since the rear brakes/tires do more work, stopping distances improve. Since the front brakes do less work, fade is reduced.
Moving the center of gravity aft also improves braking and handling. Braking improves for the reasons as above. Handling improves because the rear tires can do more of their share of the work, reducing some of the infamous understeer.
Reducing unsprung weight has the benefits listed above, but also further improves handling and ride. Reduced unsprung weight makes it easier for the springs/shocks to keep the tire patch uniformly in contact with the road. A side benefit: a higher ratio of sprung to unsprung weight also improves the ride.
Reducing rotating weight improves acceleration. Less weight in the flywheels (wheels, tires, brakes, etc) requires less energy, or HP, to spin them up to speed as the car accelerates.
Reducing the polar moment of inertia, moving the mass of the car toward the center, makes it easier to rotate the car, taking transient loads of the tires during cornering and improving handling.
There's nothing new in all this, it's just a reminder that weight affects everything! Some specific suggestions:
1. Replace the cast brake rotor with a 2-piece rotor with an aluminum hat, saving 10 lb per corner in the front and 5 lb per corner in the rear, for a total of 30 lb of rotating unsprung weight reduction, and lower polar moment of inertia; or better yet ?
1a. As an option, offer Porsche's ceramic brakes, saving 60 lb (?) of rotating unsprung weight and further improving polar moment of inertia and reducing unsprung rotating weight.
2. Locate the rear brake caliper on the leading rather than trailing edge of the rotor, improving polar moment of inertia. I know, this isn't much, but it's zero cost if done originally, and all these small details do add up to something significant.
3. Do something with the sunroof. Either make it an "option delete"; or offer the option of a fixed "moonroof", replacing the glass with Lexan. Total weight savings without glass or motors of about 25 lb (?), located very high.
4. Eliminate the double thickness glass in the side and rear windows. Standard glass would save 40 lb (?) and reduce the polar moment of inertia and lower the CG.
5. Make the hood and roof out of carbon fiber, saving 40 lb (?)
6. Allow the option of manually adjustable, ultra lightweight front seats (but of course matching the leather interior). I'd guess each S8 seat currently probably weighs about 90 lb, but it could be replaced with a 25 lb seat, saving 140 lb.
7. Replace the SS exhaust system with a titanium exhaust system, for a 25+ lb weight savings.
8. Titanium connecting rods probably save only about 6 lb, but it's all weight up front; and they'd reduce stresses on the motor.
9. With a dry sump motor, put the oil tank in the trunk. The additional plumbing may add weight, but ~20 lb of oil moves aft. Also a dry sump motor could be mounted about 2" lower in the chassis.
10. Replace the steel suspension coil springs with titanium, improving longevity and saving 20 lb, half of which is unsprung.
11. Use magnesium/aluminum, aluminum/scandium, or titanium alloys for the wheel uprights, saving 25 lb of unsprung weight.
12. Use aluminum ring gear carriers in front and rear differentials, saving ~20 lb of rotating weight.
13. Use carbon fiber valve covers, saving about 4 lb of weight up front.
14. Install a low mounted water/oil heat exchanger for the power steering fluid, or an air/oil exchanger and exhaust the hot air into the wheel well, improving polar moment of inertia. The 9-1/2 ft of bare pipe hung up high on the front of the current S8 is ridiculous.
15. Provide the option of a less massive battery, saving up to 10 lb and improving polar moment of inertia.
16. Replace every non-critical, lightly stressed steel bolt with an aluminum bolt. Feel free to use titanium bolts in critical applications.
17. Personally, I will pay for other "option deletes" such as 150 of the 200 watts of amplifier, some of the sound proofing, driver adjustable rear head rests, heated seats, power adjustable steering column, headlight washers, home link system, power this, power that, etc etc.
18. Especially in the front half of the car, look at EVERY component and decide whether it could reasonably be made lighter without sacrificing strength - items such as steel brackets, bolts, etc. Probably another 25 lb of miscellaneous savings are possible.
19. Feel free to lose some of the soundproofing. I don't mind hearing some glorious mechanical sounds.
B. Steering:
1. Use quicker steering ratio
2. Use an electric power steering pump, saving weight reducing HP drag
C. Suspension:
1. Widen track about 1-2"; didn't someone once say "wider is better"?
2. Put just a bit more negative camber in the front and a bunch more caster.
3. Add additional anti-dive anti-squat geometry
D. Brakes:
1. Any brake upgrades are always welcome, but as a minimum, no sliding calipers. I'd also use stainless steel braid -AN brake lines.
2. Improved weight distribution could require the rear rotor to go to 320 mm or perhaps even 330 mm (and that rear rotor wouldn't look so out of proportion in the wheel).
E. Wheels/tires:
1. A 19x10 wheel with a 285/35-19 tire, set a 25 lb target for wheel weight
3. Standard tire: Either the Bridgestone S-03, Michelin Pilot Sport, or Pirelli Pzero Rosso or yellow.
4. Specify a bit higher than normal front tire pressure to improve handling.
F. Chassis:
Short wheelbase!
G. Transmission:
Assuming this will be a 6-speed transmission,
1. Lose the torque converter, replacing it with an "automatic" clutch, creating a sequential Tip gearbox.
2. Set 1st gear ratio as low as necessary for PR in magazine reviews; i.e., quick 0-60 times.
3. Set 5th gear for 155 mph (or whatever speed limiter setting) at the rev limit.
4. Set 6th gear as tall as necessary for fuel economy standards.
5. Space 2nd thru 4th gears properly, using progressively higher rev range in the taller gears.
Get clever with the electronics, but remember that some of us still want control of our destiny.
H. Aerodynamics:
The body is squeaky clean and low drag, but that the nicely rounded upper surface, without even a hint of a rear spoiler, undoubtedly contributes to significant aerodynamic lift at high speed. On a vehicle with this market, I probably have as much of an aversion to wings as Audi; but as a result, the underbody needs more attention. At a minimum, a discreet but well-designed diffuser could contribute downforce without distracting from the styling. Note that A6's have a blacked out panel that from a distance even looks like a diffuser. If Audi wants to get fancy, they can figure out a way to add venturi tunnels. Perhaps a clever design could use the center muffler to narrow down the venturi tunnel, and the engine compartment could vent into the front wheelwells rather than under the car. And except for the diffuser or diffuser tunnels, the bottom of the car needs to be smooth.
I. A Wonderful Motor:
1. No question here - a 450 hp min Gallardo V10 with dry sump, and I want to be able to see it in all it's glory.
2. I'd also like to be able to hear it, a subdued but deep throated exhaust note please.
In conclusion:
Put all this together and you've lost 450+ lbs of weight, made major improvements in all aspects of performance, and even improved the ride as well. The result would be a car well beyond D2 S8, and it would run rings (Audi rings, of course) around any other 4-door sedan and even most 2-passenger sports cars.
Shedding weight is probably the best, if not the most glamorous, way to improve all aspects of the S8's performance -- acceleration, braking, and handling. The weight of the current D3 A8 is totally unacceptable.
Losing 10% of the car's weight is equivalent to adding 40 HP and improves braking, with both shorter stopping distances and reduced brake fade. Less weight also improves handling; the tires have less mass to turn into a new direction.
Lowering the center of gravity 10% is like increasing the track 6 inches; less weight is transferred laterally under cornering, suspension geometry is easier to control, and handling significantly improves. Also, less weight is transferred forward under braking. Since the rear brakes/tires do more work, stopping distances improve. Since the front brakes do less work, fade is reduced.
Moving the center of gravity aft also improves braking and handling. Braking improves for the reasons as above. Handling improves because the rear tires can do more of their share of the work, reducing some of the infamous understeer.
Reducing unsprung weight has the benefits listed above, but also further improves handling and ride. Reduced unsprung weight makes it easier for the springs/shocks to keep the tire patch uniformly in contact with the road. A side benefit: a higher ratio of sprung to unsprung weight also improves the ride.
Reducing rotating weight improves acceleration. Less weight in the flywheels (wheels, tires, brakes, etc) requires less energy, or HP, to spin them up to speed as the car accelerates.
Reducing the polar moment of inertia, moving the mass of the car toward the center, makes it easier to rotate the car, taking transient loads of the tires during cornering and improving handling.
There's nothing new in all this, it's just a reminder that weight affects everything! Some specific suggestions:
1. Replace the cast brake rotor with a 2-piece rotor with an aluminum hat, saving 10 lb per corner in the front and 5 lb per corner in the rear, for a total of 30 lb of rotating unsprung weight reduction, and lower polar moment of inertia; or better yet ?
1a. As an option, offer Porsche's ceramic brakes, saving 60 lb (?) of rotating unsprung weight and further improving polar moment of inertia and reducing unsprung rotating weight.
2. Locate the rear brake caliper on the leading rather than trailing edge of the rotor, improving polar moment of inertia. I know, this isn't much, but it's zero cost if done originally, and all these small details do add up to something significant.
3. Do something with the sunroof. Either make it an "option delete"; or offer the option of a fixed "moonroof", replacing the glass with Lexan. Total weight savings without glass or motors of about 25 lb (?), located very high.
4. Eliminate the double thickness glass in the side and rear windows. Standard glass would save 40 lb (?) and reduce the polar moment of inertia and lower the CG.
5. Make the hood and roof out of carbon fiber, saving 40 lb (?)
6. Allow the option of manually adjustable, ultra lightweight front seats (but of course matching the leather interior). I'd guess each S8 seat currently probably weighs about 90 lb, but it could be replaced with a 25 lb seat, saving 140 lb.
7. Replace the SS exhaust system with a titanium exhaust system, for a 25+ lb weight savings.
8. Titanium connecting rods probably save only about 6 lb, but it's all weight up front; and they'd reduce stresses on the motor.
9. With a dry sump motor, put the oil tank in the trunk. The additional plumbing may add weight, but ~20 lb of oil moves aft. Also a dry sump motor could be mounted about 2" lower in the chassis.
10. Replace the steel suspension coil springs with titanium, improving longevity and saving 20 lb, half of which is unsprung.
11. Use magnesium/aluminum, aluminum/scandium, or titanium alloys for the wheel uprights, saving 25 lb of unsprung weight.
12. Use aluminum ring gear carriers in front and rear differentials, saving ~20 lb of rotating weight.
13. Use carbon fiber valve covers, saving about 4 lb of weight up front.
14. Install a low mounted water/oil heat exchanger for the power steering fluid, or an air/oil exchanger and exhaust the hot air into the wheel well, improving polar moment of inertia. The 9-1/2 ft of bare pipe hung up high on the front of the current S8 is ridiculous.
15. Provide the option of a less massive battery, saving up to 10 lb and improving polar moment of inertia.
16. Replace every non-critical, lightly stressed steel bolt with an aluminum bolt. Feel free to use titanium bolts in critical applications.
17. Personally, I will pay for other "option deletes" such as 150 of the 200 watts of amplifier, some of the sound proofing, driver adjustable rear head rests, heated seats, power adjustable steering column, headlight washers, home link system, power this, power that, etc etc.
18. Especially in the front half of the car, look at EVERY component and decide whether it could reasonably be made lighter without sacrificing strength - items such as steel brackets, bolts, etc. Probably another 25 lb of miscellaneous savings are possible.
19. Feel free to lose some of the soundproofing. I don't mind hearing some glorious mechanical sounds.
B. Steering:
1. Use quicker steering ratio
2. Use an electric power steering pump, saving weight reducing HP drag
C. Suspension:
1. Widen track about 1-2"; didn't someone once say "wider is better"?
2. Put just a bit more negative camber in the front and a bunch more caster.
3. Add additional anti-dive anti-squat geometry
D. Brakes:
1. Any brake upgrades are always welcome, but as a minimum, no sliding calipers. I'd also use stainless steel braid -AN brake lines.
2. Improved weight distribution could require the rear rotor to go to 320 mm or perhaps even 330 mm (and that rear rotor wouldn't look so out of proportion in the wheel).
E. Wheels/tires:
1. A 19x10 wheel with a 285/35-19 tire, set a 25 lb target for wheel weight
3. Standard tire: Either the Bridgestone S-03, Michelin Pilot Sport, or Pirelli Pzero Rosso or yellow.
4. Specify a bit higher than normal front tire pressure to improve handling.
F. Chassis:
Short wheelbase!
G. Transmission:
Assuming this will be a 6-speed transmission,
1. Lose the torque converter, replacing it with an "automatic" clutch, creating a sequential Tip gearbox.
2. Set 1st gear ratio as low as necessary for PR in magazine reviews; i.e., quick 0-60 times.
3. Set 5th gear for 155 mph (or whatever speed limiter setting) at the rev limit.
4. Set 6th gear as tall as necessary for fuel economy standards.
5. Space 2nd thru 4th gears properly, using progressively higher rev range in the taller gears.
Get clever with the electronics, but remember that some of us still want control of our destiny.
H. Aerodynamics:
The body is squeaky clean and low drag, but that the nicely rounded upper surface, without even a hint of a rear spoiler, undoubtedly contributes to significant aerodynamic lift at high speed. On a vehicle with this market, I probably have as much of an aversion to wings as Audi; but as a result, the underbody needs more attention. At a minimum, a discreet but well-designed diffuser could contribute downforce without distracting from the styling. Note that A6's have a blacked out panel that from a distance even looks like a diffuser. If Audi wants to get fancy, they can figure out a way to add venturi tunnels. Perhaps a clever design could use the center muffler to narrow down the venturi tunnel, and the engine compartment could vent into the front wheelwells rather than under the car. And except for the diffuser or diffuser tunnels, the bottom of the car needs to be smooth.
I. A Wonderful Motor:
1. No question here - a 450 hp min Gallardo V10 with dry sump, and I want to be able to see it in all it's glory.
2. I'd also like to be able to hear it, a subdued but deep throated exhaust note please.
In conclusion:
Put all this together and you've lost 450+ lbs of weight, made major improvements in all aspects of performance, and even improved the ride as well. The result would be a car well beyond D2 S8, and it would run rings (Audi rings, of course) around any other 4-door sedan and even most 2-passenger sports cars.
02-28-2004, 02:01 PM
#4
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You'll be sorry you asked: Part 2, electronic
Four position ESP switch
1. Normal - current
2. Sport - correct for understeer only, never reduce throttle
3. Snow - quicker to reduce throttle
4. Off
Three position 6-speed Tip, auto
1. Normal - current smart adaptive
2. Sport - adaptive off, higher minimum shift rpm and quicker kickdown
3. Snow - always very short shifts, reluctant to kickdown, start in 2nd gear
Three position Servotronic power steering
1. Normal - current
2. Sport - off
3. Snow - off above 10 mph
Three position electronic shocks
1. Normal - current
2. Sport - stiffer
3. Snow - softer
Obviously you could have just one three position switch (normal, sport, snow) that simultaneously affects ESP, Tip, Servotronic steering, and shocks.
And finally, deactivate ABS if yaw sensors detect a spinning car -- a version of the "spin, two in" (but without the clutch pedal to push in). If the car is totally out of control, it's almost always better to have the brakes locked and slide in a straight line; rather than to have the tires reestablish grip at some point, and then the car darts in an unpredictable direction.
I'd love to be involved with tuning a "Sport" ESP setting; there's got to be tremendous potential to dramatically improve the handling of the car, in ways that are forbidden even in F1. Routinely using the brakes to help rotate the car, though, would require a serious upgrade to both the front & rear S8 brakes. I don't believe anyone's yet doing this type electronic handling enhancement; I believe everyone's using electronics to wait until something's gone "wrong" before they acting
1. Normal - current
2. Sport - correct for understeer only, never reduce throttle
3. Snow - quicker to reduce throttle
4. Off
Three position 6-speed Tip, auto
1. Normal - current smart adaptive
2. Sport - adaptive off, higher minimum shift rpm and quicker kickdown
3. Snow - always very short shifts, reluctant to kickdown, start in 2nd gear
Three position Servotronic power steering
1. Normal - current
2. Sport - off
3. Snow - off above 10 mph
Three position electronic shocks
1. Normal - current
2. Sport - stiffer
3. Snow - softer
Obviously you could have just one three position switch (normal, sport, snow) that simultaneously affects ESP, Tip, Servotronic steering, and shocks.
And finally, deactivate ABS if yaw sensors detect a spinning car -- a version of the "spin, two in" (but without the clutch pedal to push in). If the car is totally out of control, it's almost always better to have the brakes locked and slide in a straight line; rather than to have the tires reestablish grip at some point, and then the car darts in an unpredictable direction.
I'd love to be involved with tuning a "Sport" ESP setting; there's got to be tremendous potential to dramatically improve the handling of the car, in ways that are forbidden even in F1. Routinely using the brakes to help rotate the car, though, would require a serious upgrade to both the front & rear S8 brakes. I don't believe anyone's yet doing this type electronic handling enhancement; I believe everyone's using electronics to wait until something's gone "wrong" before they acting
02-29-2004, 07:46 AM
#6
Wow Randy, you have really given this some thought.
I guess some of this is doable as mods. The sunroof could be removed and a new carbon fiber kit installed. The brakes should be a commercial item. The hood could be carbon fiber. New lighter seats could be bought.
Overall, I agree that it needs to be done at the factory to give it that great Audi finish.
Overall, I agree that it needs to be done at the factory to give it that great Audi finish.
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