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Thread: O/T Flying Bug
12-14-2005 07:27 PM #1
O/T Flying Bug
Have you been keeping up with the recent press on the finally released Bugatti Veyron? Let's ignore, for the moment, its "styling" and instead try to come to grips with its performance. Would you believe its 8 Liter W16 motor has 4 turbochargers, sends 1000 HP to the wheels and can propel the car to over 250 MPH? Believe it. In fact, that engine actually produces 3000 HP but 1000 is lost to the cooling system and another thousand goes out the exhaust pipes! It even has a "Power" gauge which tells you how much HP the engine is producing at any particular time. 0-62 takes 2.5 seconds, 125 MPH comes up in 7.3 seconds which is faster than Schumacher's F2005 F1 car can get there, 188 MPH is passed in 16.7 seconds and 250 MPH is reached in 55 seconds. This is the fastest, most powerful, street legal automobile ever produced, and it is built by Volkswagen! Amazing! Grease Monkey
12-14-2005 10:41 PM #2
Re: O/T Flying Bug
can you explain the "chain of physics" regarding the lost hp to the cooling and exhaust sytems, and how different is it from a normal internal combustion driven car? The car is amazing and so over the top that it appears to be loony tunes, like the spruce goose (except this thing can really run--although in original design I hear it was squirrely as hell and dangerous to the extreme, thus the long delay).
12-15-2005 12:57 PM #3
Re: O/T Flying Bug
In order for the engine to make that kind of HP, it must burn an inordinate amount of fuel. EPA ratings are 7mpg city and 10 mpg highway! Perhaps more tellingly, the mpg rating at full power is 3 mpg! As a result of all that gasoline being burned in such a short time, a tremendous amount of energy is released and most of it is in the form of heat. Some of that heat is used to power the car, but most of it is unproductive and must be removed to keep the engine from overheating. This was one of the biggest challenges the VW engineers had to overcome to make the car streetable. The Veyron ended up with 4 radiators and 4 cooling fans to control the heat production. Keep in mind that all internal combustion engines produce excess heat (due to the inefficiency of the combustion process and internal friction produced by moving parts) which cannot be used to power the car. This efficiency factor is around 20% in most cars today, meaning that only 20% of the energy produced from the gasoline is used to power the car and 80% is lost as heat, so the Veyron's engine is actually doing a better job (mostly due to its quad turbo set-up) but the levels of output involved are so high that the numbers seem outrageous.
Another interesting point relating to the extreme world the Veyron lives in and the forces which must be overcome to achieve that level of performance is that it only takes 500 HP to propel the car to 185 MPH but the last 65 MPH requires another 500 HP! This also means that if you are traveling 185 MPH in the Veyron and punch it, you have 500 HP to accelerate the car. Simply amazing!
The primary reason the early versions of the Veyron were so problematic was because they started with a stylized body design posessing marginal aerodynamics and promised 250 MPH and 1000 HP from it before they had done the engineering work to determine how to achieve that level of performance. On the McLaren F1, the engineering work was done first (a much better approach) and then a body was designed to work with the engine and chassis. The difference in approaches is instructive when you consider that the F1, a much lighter and more aerodynamic car, would only need 740 HP to go 250 MPH. Paradoxically, a great deal of the Veyron's high aerodynamic drag is due to its excessive cooling needs (channeled air passing through mulitple radiators) so by promising 1000 HP, their engineers were saddled with a high CD and thus needed 1000 HP to overcome it. The truth is, given the obstacles they faced, the VW engineers worked a small miracle to get the Veyron to perform at the promised level. Grease Monkey
12-15-2005 01:38 PM #4
12-15-2005 02:26 PM #5
Re: It's never dull with GM.
Veyron costs $1,250,000. If you put down a $375,000 deposit, you can get a demo ride. Once you pay for the car, you will be invited to Ehra-Lessien in Germany, VW's 13 mile test track, where you can take your new Veyron up to 250+ MPH. On the other hand, I know some deserted roads in Montana where I'd be willing to bet we could match that speed, so if any Veyron owner wants to stretch those legs a bit, Z8 Bob and I will chip in for the gas!Grease Monkey
12-15-2005 03:29 PM #6
Don't be too eager with the gas
On the British Top Gear show, they drove this beast across Europe. One interesting stat: The gas tank is 100 liters. At full speed, its empty in 12 minutes.
So many intersting stats in this car:
- Due to the heat - no engine cover, its open to the sky.
- To get to full speed, you need to enable the 'full speed' mode by using the key in a slot just inside the door. This locks the tail wing down and lowers the ride height.
- To get their full speed, they made the wing mirrors smaller, and then found that they lost front end stability.
- Above something like 230mph, they need 26HP to go 1 mph faster
- If you were in a race to 200 mph with a McLaren F1, you could let the F1 get to 120MPH before setting off and still beat it.
12-15-2005 03:47 PM #7
12-15-2005 08:33 PM #8
12-16-2005 12:33 AM #9
12-16-2005 11:17 AM #10
12-16-2005 11:58 AM #11
Re: Don't be too eager with the gas
I don't have any specific 0-200 MPH data for the McLaren F1 but I would be surprised if it was that much slower to 200 MPH. The reason I say this is because the F1's pounds per horsepower measurement is 3.9 while the Veyron's is 4.3. If we factor in the CD of the F1 at .32 vs the Veyron's best of .36 (in 250 MPH trim which wouldn't provide the best acceleration time), the numbers just don't add up. The Veyron would certainly have an advantage at launch due to its all-wheel drive and very aggressive launch control, but once rolling, the F1 should be very competitive. The only significant diffference I can imagine might be in the gearing. Perhaps you have some more info on this subject? Also, to keep things in perspective, the only 0-200 MPH time I can find for the Veyron is 22 seconds (estimated by Car and Driver) which has been bettered by a Hennessey Viper TT which got there in 21.3 seconds and was closely followed by a Saleen S7 Twin Turbo which hit 200 MPH in 23.4 seconds. For reference, the Hennessey Viper has a pounds per horsepower measurement of 3.4 and the Saleen S7's is 3.9.Grease Monkey
12-16-2005 03:03 PM #12
12-19-2005 08:46 PM #13
Re: O/T Flying Bug
The Veyron is fast, but the Saleen S7 Twin Turbo is now available with a 1,000 hp option.
<b>Saleen S7 takes on Veyron</b>
Wednesday 7th December 2005
Saleen is now offering buyers of its 750 bhp S7 Twin Turbo supercar the option of a 'performance upgrade'. It costs £46,500 on top of the S7's £320,000 list price and boosts the 7-litre twin-turbo V8 to a claimed 1000 bhp. Coupled with a relatively light kerbweight of 1338 kg, the huge power should allow the S7 to challenge the Bugatti Veyron as the fastest production car in the world. And with 75 examples of the S7 already delivered in the US, the Saleen certainly has every right to claim the title.
Even with the 'cooking' 750 bhp engine, the S7 Twin Turbo is said to be good for a sub-three second run to 60 mph, and 100 mph flashes up in a claimed six seconds flat. Currently Saleen claims a top speed of 240 mph for the S7 Twin Turbo but with the 1000 bhp upgrade there are whispers that the car has already topped over 260 mph in testing.
(end of article)
"Expect a future intercooled version with almost twice the boost to make over 1000 bhp."
- Road & Track
The new S7 Twin Turbo runs 5.5 psi of boost.
12-19-2005 09:33 PM #14
12-20-2005 01:32 PM #15
Re: Don't trust the BBC
Actually, if Kaptain is correct and the F1 takes 28 seconds to reach 200 MPH, then the BBC report might actually be true. The explanation for why the Veyron, with a higher weight to HP ratio would accelerate so much faster, is probably related to 3 factors:
Better launch due to sophisticated electronic launch control, wider tires, and all-wheel drive.
7-speed transmission should provide better gearing for maximum acceleration and potentially a higher top speed.
Much higher torque output of Veyron engine. The lb/torque ratio for the F1 is 5.1 and for the Veyron it is 4.7 so there is a very real advantage. Horsepower allows a car to achieve maximum speed but torque (plus gearing and drag) determines how fast it gets there.Grease Monkey
12-20-2005 09:49 PM #16
Re: Don't trust the BBC
I got the stat from Autocar May 11 1994.
60-160 mph in 11.4 seconds
60-80 in 1.2 seconds in second gear
0-100 in 6.3
0-110 in 7.2
120-140 in 2.3 seconds in 4th gear
150-170 in 3.5 seconds in 5th gear (0.5 seconds slower than it accelerates from 80-100 in the same gear)
1/4 mile in 11.1 seconds at 138 mph
It doesn't have stats on handling.
Kerb weight including 1/2 tank of fuel = 1138 kg
It was included with more tests of the McLaren F1 in a Brooklands road test book.
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