RE: Bugatti Supersport With 1200hp: Truth Or Fiction?
Discussion
Regarding the top speed being limited to 253.8mph, I’m sure I remember reading/hearing it was because of the tyres.
I know VW/Bug had to develop the tyres the veyron uses specially for it because no one made road tyres that could hold up to the huge forces generated at such massive speeds.
You will notice I said road tyres because I know other cars ran faster before and since but I would question how long the tyres lasted or if they could repeat terminal velocity runs on the same set.
Anyway Im pretty sure they deemed 253.8mph (the fastest car in the world at the time) quite fast enough AND it was repeatable safely on the same set of tyres.
I know VW/Bug had to develop the tyres the veyron uses specially for it because no one made road tyres that could hold up to the huge forces generated at such massive speeds.
You will notice I said road tyres because I know other cars ran faster before and since but I would question how long the tyres lasted or if they could repeat terminal velocity runs on the same set.
Anyway Im pretty sure they deemed 253.8mph (the fastest car in the world at the time) quite fast enough AND it was repeatable safely on the same set of tyres.
leon9191 said:
Regarding the top speed being limited to 253.8mph, I’m sure I remember reading/hearing it was because of the tyres.
I know VW/Bug had to develop the tyres the veyron uses specially for it because no one made road tyres that could hold up to the huge forces generated at such massive speeds.
You will notice I said road tyres because I know other cars ran faster before and since but I would question how long the tyres lasted or if they could repeat terminal velocity runs on the same set.
Anyway Im pretty sure they deemed 253.8mph (the fastest car in the world at the time) quite fast enough AND it was repeatable safely on the same set of tyres.
That's a possibility. I did hear that they chose the speed they did because it was "more than fast enough", but it still doesn't explain why they would use an electronic limiter to rein in a car that's effectively more powerful and therefore heavier/less reliable than it needs to be to reach the headline speed. I know VW/Bug had to develop the tyres the veyron uses specially for it because no one made road tyres that could hold up to the huge forces generated at such massive speeds.
You will notice I said road tyres because I know other cars ran faster before and since but I would question how long the tyres lasted or if they could repeat terminal velocity runs on the same set.
Anyway Im pretty sure they deemed 253.8mph (the fastest car in the world at the time) quite fast enough AND it was repeatable safely on the same set of tyres.
I'm not so sure about the top speed being very repeatable, though, because wasn't it said that the tyres will only last for quarter of an hour at that speed? Given the time it takes to reach the top speed, I reckon that only gives you three, maybe five, runs per set of tyres. What happens to them after that fifteen minutes at VMax, I don't know..
That said, perhaps the biggest problem is the heat that builds up in the tyres, so if you ran at VMax for ten minutes then pulled over, refuelled and cooled them off, perhaps you could do it all again, all day? Or until the Gulf runs dry, one or the other
Edited by McSam on Thursday 17th June 10:20
spoonoff said:
Frimley111R said:
No.The Veyron is an exquisitely engineered hypercar-to-end-all-hypercars and has all the money, influence and resources of the VW group to draw on.
The Venom is someone’s project, built in a shed, on a shoestring, which will go backwards into a hedge the first time it’s driver puts their foot down. It just happens to have the patronage of some of the PH team who are mates with the constructors.
Edited by ptopman on Thursday 17th June 10:38
McSam said:
I did hear that they chose the speed they did because it was "more than fast enough", but it still doesn't explain why they would use an electronic limiter to rein in a car that's effectively more powerful and therefore heavier/less reliable than it needs to be to reach the headline speed.
I'm not so sure about the top speed being very repeatable, though, because wasn't it said that the tyres will only last for quarter of an hour at that speed? Given the time it takes to reach the top speed, I reckon that only gives you three, maybe five, runs per set of tyres. What happens to them after that fifteen minutes at VMax, I don't know..
That said, perhaps the biggest problem is the heat that builds up in the tyres, so if you ran at VMax for ten minutes then pulled over, refuelled and cooled them off, perhaps you could do it all again, all day? Or until the Gulf runs dry, one or the other
A car's power output, particularly turbocharged cars is fairly variable dependent on climate. The car's probably engineered to do its stated Vmax under normal conditions, but under certain circumstances (cold weather for example) the engine might be capable of producing more power, or exceeding its nominal top speed purely because of air density, and therefore being capable of exceeding the limitations of the tyres and perhaps even aerodynamics. Hence it would be sensible to cap it.I'm not so sure about the top speed being very repeatable, though, because wasn't it said that the tyres will only last for quarter of an hour at that speed? Given the time it takes to reach the top speed, I reckon that only gives you three, maybe five, runs per set of tyres. What happens to them after that fifteen minutes at VMax, I don't know..
That said, perhaps the biggest problem is the heat that builds up in the tyres, so if you ran at VMax for ten minutes then pulled over, refuelled and cooled them off, perhaps you could do it all again, all day? Or until the Gulf runs dry, one or the other
Also, as said before, the Veyron would have to be pretty close to critical gearing (on the limiter at Vmax) to hit 252mph with its nominal 1000bhp output, perhaps any 'extra' availability in terms of RPM would be down to the availability or mechanical practicality of the gear sets necessary to achieve the precise ratio. Let's not forget you're probably talking about 0.01:1 differences in Ratio for 5mph differences at that speed, and at the end of the day, a gear ratio is just x number of teeth on the input over y number of teeth on the output.
OR it could be that under nominal circumstances the Veyron produces peak power at a significantly lower RPM than the limiter, in which case if the gearing were shorter it might not actually be capable of hitting the nominal Vmax.
Whichever way, it's not because the car is overspecced, that's for sure!
Also, the tyre's survivability will almost certainly be heat build up, rather than any sort of 'finite life'. In fact I once heard that the tyre manufacturers were worried about the vmax duration requirements placed on them (probably some typically pulled out of a hat figure like 30 minutes), saying it couldn't be done much to the concern of Bugatti, until Bugatti realised that at full speed it would empty the tank in 5 minutes less than the tyre manufacturer's quoted maximum 'life time'!
The Wookie said:
In fact I once heard that the tyre manufacturers were worried about the vmax duration requirements placed on them (probably some typically pulled out of a hat figure like 30 minutes), saying it couldn't be done much to the concern of Bugatti, until Bugatti realised that at full speed it would empty the tank in 5 minutes less than the tyre manufacturer's quoted maximum 'life time'!
The Veyron is the concorde of the car world. I bloody love it. Probably wont ever see anything like this again once they stop production.
There are a lot of people that dont appreciate what has been done, as other people have said its not just a case of plonking a 1000bhp engine in. Its a totally useable, luxurious package that can be driven by pretty much anyone. Thats impressive.
There are a lot of people that dont appreciate what has been done, as other people have said its not just a case of plonking a 1000bhp engine in. Its a totally useable, luxurious package that can be driven by pretty much anyone. Thats impressive.
The Wookie said:
McSam said:
I did hear that they chose the speed they did because it was "more than fast enough", but it still doesn't explain why they would use an electronic limiter to rein in a car that's effectively more powerful and therefore heavier/less reliable than it needs to be to reach the headline speed.
I'm not so sure about the top speed being very repeatable, though, because wasn't it said that the tyres will only last for quarter of an hour at that speed? Given the time it takes to reach the top speed, I reckon that only gives you three, maybe five, runs per set of tyres. What happens to them after that fifteen minutes at VMax, I don't know..
That said, perhaps the biggest problem is the heat that builds up in the tyres, so if you ran at VMax for ten minutes then pulled over, refuelled and cooled them off, perhaps you could do it all again, all day? Or until the Gulf runs dry, one or the other
A car's power output, particularly turbocharged cars is fairly variable dependent on climate. The car's probably engineered to do its stated Vmax under normal conditions, but under certain circumstances (cold weather for example) the engine might be capable of producing more power, or exceeding its nominal top speed purely because of air density, and therefore being capable of exceeding the limitations of the tyres and perhaps even aerodynamics. Hence it would be sensible to cap it.I'm not so sure about the top speed being very repeatable, though, because wasn't it said that the tyres will only last for quarter of an hour at that speed? Given the time it takes to reach the top speed, I reckon that only gives you three, maybe five, runs per set of tyres. What happens to them after that fifteen minutes at VMax, I don't know..
That said, perhaps the biggest problem is the heat that builds up in the tyres, so if you ran at VMax for ten minutes then pulled over, refuelled and cooled them off, perhaps you could do it all again, all day? Or until the Gulf runs dry, one or the other
Also, as said before, the Veyron would have to be pretty close to critical gearing (on the limiter at Vmax) to hit 252mph with its nominal 1000bhp output, perhaps any 'extra' availability in terms of RPM would be down to the availability or mechanical practicality of the gear sets necessary to achieve the precise ratio. Let's not forget you're probably talking about 0.01:1 differences in Ratio for 5mph differences at that speed, and at the end of the day, a gear ratio is just x number of teeth on the input over y number of teeth on the output.
OR it could be that under nominal circumstances the Veyron produces peak power at a significantly lower RPM than the limiter, in which case if the gearing were shorter it might not actually be capable of hitting the nominal Vmax.
Whichever way, it's not because the car is overspecced, that's for sure!
Also, the tyre's survivability will almost certainly be heat build up, rather than any sort of 'finite life'. In fact I once heard that the tyre manufacturers were worried about the vmax duration requirements placed on them (probably some typically pulled out of a hat figure like 30 minutes), saying it couldn't be done much to the concern of Bugatti, until Bugatti realised that at full speed it would empty the tank in 5 minutes less than the tyre manufacturer's quoted maximum 'life time'!
makes you wonder... did they limit the fuel tank's size so you couldn't blow up the tyres? McSam said:
leon9191 said:
Regarding the top speed being limited to 253.8mph, I’m sure I remember reading/hearing it was because of the tyres.
I know VW/Bug had to develop the tyres the veyron uses specially for it because no one made road tyres that could hold up to the huge forces generated at such massive speeds.
You will notice I said road tyres because I know other cars ran faster before and since but I would question how long the tyres lasted or if they could repeat terminal velocity runs on the same set.
Anyway Im pretty sure they deemed 253.8mph (the fastest car in the world at the time) quite fast enough AND it was repeatable safely on the same set of tyres.
That's a possibility. I did hear that they chose the speed they did because it was "more than fast enough", but it still doesn't explain why they would use an electronic limiter to rein in a car that's effectively more powerful and therefore heavier/less reliable than it needs to be to reach the headline speed. I know VW/Bug had to develop the tyres the veyron uses specially for it because no one made road tyres that could hold up to the huge forces generated at such massive speeds.
You will notice I said road tyres because I know other cars ran faster before and since but I would question how long the tyres lasted or if they could repeat terminal velocity runs on the same set.
Anyway Im pretty sure they deemed 253.8mph (the fastest car in the world at the time) quite fast enough AND it was repeatable safely on the same set of tyres.
Edited by McSam on Thursday 17th June 10:20
The Wookie said:
A car's power output, particularly turbocharged cars is fairly variable dependent on climate. The car's probably engineered to do its stated Vmax under normal conditions, but under certain circumstances (cold weather for example) the engine might be capable of producing more power, or exceeding its nominal top speed purely because of air density, and therefore being capable of exceeding the limitations of the tyres and perhaps even aerodynamics. Hence it would be sensible to cap it.
Oops.. I completely forgot to take atmospheric variables into account 
. I was still living in a theoretical world where peak power is just that, but of course there are a stack of possibilities and limiting the speed does indeed make sense - if the speed is limited to the maximum speed at which Bugatti tested the car, if you see what I mean. My thinking now is that they didn't take it around their oval and get 260mph, think it was too fast and drop it to 253, but rather, it did 253mph and they thought "we'd better make sure it doesn't do any more on a cold day if someone gets lucky with the wind, because we've no idea what might happen". Does that sound more sensible than what I said earlier?The Wookie said:
Also, as said before, the Veyron would have to be pretty close to critical gearing (on the limiter at Vmax) to hit 252mph with its nominal 1000bhp output, perhaps any 'extra' availability in terms of RPM would be down to the availability or mechanical practicality of the gear sets necessary to achieve the precise ratio. Let's not forget you're probably talking about 0.01:1 differences in Ratio for 5mph differences at that speed, and at the end of the day, a gear ratio is just x number of teeth on the input over y number of teeth on the output.
OR it could be that under nominal circumstances the Veyron produces peak power at a significantly lower RPM than the limiter, in which case if the gearing were shorter it might not actually be capable of hitting the nominal Vmax.
Whichever way, it's not because the car is overspecced, that's for sure!
Yeah - again, I was living in a theoretical world where I forgot that we can't just have any precise gear ratio we choose. Making more sense now OR it could be that under nominal circumstances the Veyron produces peak power at a significantly lower RPM than the limiter, in which case if the gearing were shorter it might not actually be capable of hitting the nominal Vmax.
Whichever way, it's not because the car is overspecced, that's for sure!
. Do you think the car actually would be on the rev limiter at 253mph, and that's what restrains it so people don't feel "cheated" by an actual speed restrictor?The Wookie said:
Also, the tyre's survivability will almost certainly be heat build up, rather than any sort of 'finite life' [...]
That, then, makes more sense. It seemed unlikely that you'd need some sort of record of how fast the tyres had been and for how long, to make sure they weren't about to blow themselves apart - like a sort of airframe stress meter!You know you've got a proper engine when flat-out fuel range from a 100L tank is expressed in minutes, and not very many of them at that
Engineer1 said:
The reason for limiting is simple if you advertise a 1000bhp, 250+ mph car then it better be 1000bhp and capable of its top speed, it is after all a production car. With a tuned vehicle people are likely to accept that the top speed is only achievable on a cold day at sea level or other restrictions but for a production car built for bragging rights it had better be able to meet the spec consistently and in almost any conditions. What would the lesser motoring press say if the car had 990bhp and topped out at 220? It would be very difficult to explain away as any technical reasons would sound like excuses.
Also perfectly reasonable.. Much the same as the reason a lot of manufacturers quote power and acceleration figures conservatively, I guess? At a glance, it would make sense to claim figures from the very best situation you tested because the car is capable of it, but I suppose this policy only works until someone turns up with a dyno printout and a temper How accurate do you think the speedometer is in the car? As far as I know, legally it must never read under the speed the car's doing, which means for a bit of a safety margin it would ordinarily read high.. So surely, with the error magnified at such high speeds, you'd easily get 260+ on the clock?
spoonoff said:
Frimley111R said:
No.The Veyron is an exquisitely engineered hypercar-to-end-all-hypercars and has all the money, influence and resources of the VW group to draw on.
The Venom is someone’s project, built in a shed, on a shoestring, which will go backwards into a hedge the first time it’s driver puts their foot down. It just happens to have the patronage of some of the PH team who are mates with the constructors.
snorkel sucker said:
hmmmm.... im no mathematician but would that gain in horsepower really relate to that incresed top speed??
I thought that for every extra mph above what the veyron already does, that requires a not inconsiderable hp increase to overcome the drag....
anyone brighter than me care to help me out?!!
Somewhere in the region of 276 mph. Although I'm assuming they will try and add a little more downforce at those speedsnevertheless there is no road in the world you can get close on except test tracks and if you're going to spend that much money just to go fast why wouldn't you just take up a hobby in drag racingI thought that for every extra mph above what the veyron already does, that requires a not inconsiderable hp increase to overcome the drag....
anyone brighter than me care to help me out?!!
McSam said:
Using the Veyron's aero model, 300mph would require 1670bhp.
Which is quite a lot
450kph, an altogether more reasonable (hah!) 279.7mph, is more like 1340bhp - provided my calculations stand up at such speeds.
you could get away with 700 BHP in one of theseWhich is quite a lot
450kph, an altogether more reasonable (hah!) 279.7mph, is more like 1340bhp - provided my calculations stand up at such speeds.
Edited by McSam on Friday 18th June 16:26
The super aero car is called an Aptera.
http://www.aptera.com
http://www.aptera.com
Edited by Fresh_Clip on Monday 21st June 00:52
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