Bugatti breaks 300 mph barrier with a modified Chiron

[Maritimer]

Bugatti have a new car they're gonna unveil next week. It looks unlike anything they have made so far
https://youtu.be/2ZiTKr_ALjk

Le Mans hypercar??
Looks pretty cool, and if it is, Le Mans could be interesting again

Their usual engine is too big for hypercar, so unless this one is just a V8 itll be a track day special.

[MrMuffins]

The two way average was significantly lower 330 was the peak, so it's hard to say.
Apparently the driver backed off, and I don't blame em, I wouldn't want to be in that car if the tyres let go though, holy ---! Michelin was already scared to let Koenigsegg run the Regera flat out, peaking at 330 is clearly pushing tyre tech, hell no aircraft is ever on the ground at that speed.

It definitely could have gone a lot faster than 330, with the caveat that gearing may have limited it. Hard to say how close to redline it was, but the way it was accruing speed from 320-330 was the way the Chiron did so from 270-280, so the speed was definitely not power limited.

Hard to say about the tires; it's uncharted territory. Those Cup 2Rs (same as Chiron) can clearly handle 300+ on the much heavier Chiron. Plus, the Chiron's tires are much wider, thus adding considerable more centripetal forces to the tire carcass as a whole. The increase in force from going 300 to going, say, 340 is not a whole lot more. But If 335 is the failure point of the tire, I suppose it doesn't matter.

Top fuel dragsters have tires that are many times the mass of the Cup 2Rs and they easily hit 300+ without issue and these cars are producing 12,000+ Lbs of downforce at that speed. Granted, it's a completely different tire and purpose, but the precedent of a rubber tire than can handle it is there.

FWIW, the driver of the Tuatara said he backed off because of crosswind on the 330 run, and that he was slightly hesitant on the first run at 'only' 300.

There was one more gear available that wasn't used in the 331 run so there was a good amount of push still on tap i think.

[RZS10]

Those statements are consistent with Christian von Koenigsegg's who said that the top speed of the Jesko will be limited by "sanity" - at this point it's basically the cojones on the driver which decide the top speed

[J.A.W.]

The two way average was significantly lower 330 was the peak, so it's hard to say.
Apparently the driver backed off, and I don't blame em, I wouldn't want to be in that car if the tyres let go though, holy ---! Michelin was already scared to let Koenigsegg run the Regera flat out, peaking at 330 is clearly pushing tyre tech, hell no aircraft is ever on the ground at that speed.

Nah, its all hype, there is no "barrier", & how long ago was the land speed record below 300mph?
90 years ago, maybe? On pneumatic tyres, driving across beach-sand/salt back then too, of course.

(& if of interest, the Concorde airliner flown over 1/2 a century ago had tyres rated
to 250mph for take-off, while supporting a huge aircraft pushing hard to V.1/'rotate')...

[Tommy Cookers]

the barrier is why the wheels are high
because the tyre needs enough time for the flattened bit to recover its curved shape before it's needed again
otherwise - the standing wave effect

[JRodrigues]

Bugatti have a new car they're gonna unveil next week. It looks unlike anything they have made so far
https://youtu.be/2ZiTKr_ALjk

Le Mans hypercar??
Looks pretty cool, and if it is, Le Mans could be interesting again

Their usual engine is too big for hypercar, so unless this one is just a V8 itll be a track day special.

It does have a competition style fuel filler. Do other 'track-day specials' have the same?

[Just_a_fan]

The two way average was significantly lower 330 was the peak, so it's hard to say.
Apparently the driver backed off, and I don't blame em, I wouldn't want to be in that car if the tyres let go though, holy ---! Michelin was already scared to let Koenigsegg run the Regera flat out, peaking at 330 is clearly pushing tyre tech, hell no aircraft is ever on the ground at that speed.

Nah, its all hype, there is no "barrier", & how long ago was the land speed record below 300mph?
90 years ago, maybe? On pneumatic tyres, driving across beach-sand/salt back then too, of course.

(& if of interest, the Concorde airliner flown over 1/2 a century ago had tyres rated
to 250mph for take-off, while supporting a huge aircraft pushing hard to V.1/'rotate')...

Big difference between those examples and a road car that has to be expected to drive on varied roads with all manner of debris on them, in all conditions, and last for many thousands of miles between tyre changes.

Sure, you can put a brand new tyre on a car and drive it at silly speeds on a closed track with reasonable impunity. But try that same thing on tyres that have done several thousand miles on typical public roads and see how the tyres respond. The pucker factor would be higher, that's for sure.

Concorde, at 250mph, wasn't putting lots of load down through the tyres - the big sticky out bits at the side were lifting the weight upwards by then.

[J.A.W.]

The two way average was significantly lower 330 was the peak, so it's hard to say.
Apparently the driver backed off, and I don't blame em, I wouldn't want to be in that car if the tyres let go though, holy ---! Michelin was already scared to let Koenigsegg run the Regera flat out, peaking at 330 is clearly pushing tyre tech, hell no aircraft is ever on the ground at that speed.

Nah, its all hype, there is no "barrier", & how long ago was the land speed record below 300mph?
90 years ago, maybe? On pneumatic tyres, driving across beach-sand/salt back then too, of course.

(& if of interest, the Concorde airliner flown over 1/2 a century ago had tyres rated
to 250mph for take-off, while supporting a huge aircraft pushing hard to V.1/'rotate')...

Big difference between those examples and a road car that has to be expected to drive on varied roads with all manner of debris on them, in all conditions, and last for many thousands of miles between tyre changes.

Sure, you can put a brand new tyre on a car and drive it at silly speeds on a closed track with reasonable impunity. But try that same thing on tyres that have done several thousand miles on typical public roads and see how the tyres respond. The pucker factor would be higher, that's for sure.

Concorde, at 250mph, wasn't putting lots of load down through the tyres - the big sticky out bits at the side were lifting the weight upwards by then.

Not quite, since these days high-performance tyres specially fitted for track days,
(presumably including Vmax runs under controlled conditions) are fairly routine,
& not so dissimilar in principle to 'summer/M & S' dual tyre fitments in snowy climes.

Not quite right on Concorde either, as her delta wing planform's high AoA stance on
take-off necessitated an additional pair of main-gear wheels in the trailing position
to prevent any possibility of tail-strike, at max-speed & in ground effect aeroforce...

[JRodrigues]

[Maritimer]

Le Mans hypercar??
Looks pretty cool, and if it is, Le Mans could be interesting again

Their usual engine is too big for hypercar, so unless this one is just a V8 itll be a track day special.

It does have a competition style fuel filler. Do other 'track-day specials' have the same?

I didnt notice that actually, there are track only cars like the Ferrari FXX series that do. It could be an ultimate track toy kinda deal.

[Holm86]

https://www.thedrive.com/news/37308/the ... RgRqUEyRX0

[humble sabot]

......
Not quite, since these days high-performance tyres specially fitted for track days,
(presumably including Vmax runs under controlled conditions) are fairly routine,
& not so dissimilar in principle to 'summer/M & S' dual tyre fitments in snowy climes.

Not quite right on Concorde either, as her delta wing planform's high AoA stance on
take-off necessitated an additional pair of main-gear wheels in the trailing position
to prevent any possibility of tail-strike, at max-speed & in ground effect aeroforce...

All of those factors reduce load on the tyres by the 'rated' 250, and 250 is still very far from 330. And a takeoff roll is only a few seconds versus almost a minute of driving power through those tyres.

and cheeRS's point about top fuel dragsters is even less relevant because those tyres are specifically designed for the job have a much longer circumference so rotate slower for a given speed, and are also very soft on purpose and are only spinning under power for three seconds.

LSR tyres are very specific creatures, negligible downforce and side loads, and usually very tall.
The last Bluebird LSR car was initially limited by the tyres.


All of this neglects the controversy about the record itself anyway.

[J.A.W.]

......
Not quite, since these days high-performance tyres specially fitted for track days,
(presumably including Vmax runs under controlled conditions) are fairly routine,
& not so dissimilar in principle to 'summer/M & S' dual tyre fitments in snowy climes.

Not quite right on Concorde either, as her delta wing planform's high AoA stance on
take-off necessitated an additional pair of main-gear wheels in the trailing position
to prevent any possibility of tail-strike, at max-speed & in ground effect aeroforce...

All of those factors reduce load on the tyres by the 'rated' 250, and 250 is still very far from 330. And a takeoff roll is only a few seconds versus almost a minute of driving power through those tyres.

and cheeRS's point about top fuel dragsters is even less relevant because those tyres are specifically designed for the job have a much longer circumference so rotate slower for a given speed, and are also very soft on purpose and are only spinning under power for three seconds.

LSR tyres are very specific creatures, negligible downforce and side loads, and usually very tall.
The last Bluebird LSR car was initially limited by the tyres.


All of this neglects the controversy about the record itself anyway.

"Reduce load..."

No, since Concorde as a supersonic delta design - put its weight on its tyres 'til lift-off,
& of course, on landing too - with instantaneous acceleration on touch-down, then
followed by massive braking forces.

AFAIR, aircraft tyres have also been used on land speed vehicles,
such as the giant diesel trucks at Bonneville.

[Andres125sx]

......
Not quite, since these days high-performance tyres specially fitted for track days,
(presumably including Vmax runs under controlled conditions) are fairly routine,
& not so dissimilar in principle to 'summer/M & S' dual tyre fitments in snowy climes.

Not quite right on Concorde either, as her delta wing planform's high AoA stance on
take-off necessitated an additional pair of main-gear wheels in the trailing position
to prevent any possibility of tail-strike, at max-speed & in ground effect aeroforce...

All of those factors reduce load on the tyres by the 'rated' 250, and 250 is still very far from 330. And a takeoff roll is only a few seconds versus almost a minute of driving power through those tyres.

and cheeRS's point about top fuel dragsters is even less relevant because those tyres are specifically designed for the job have a much longer circumference so rotate slower for a given speed, and are also very soft on purpose and are only spinning under power for three seconds.

LSR tyres are very specific creatures, negligible downforce and side loads, and usually very tall.
The last Bluebird LSR car was initially limited by the tyres.


All of this neglects the controversy about the record itself anyway.

"Reduce load..."

No, since Concorde as a supersonic delta design - put its weight on its tyres 'til lift-off,
& of course, on landing too - with instantaneous acceleration on touch-down, then
followed by massive braking forces.

AFAIR, aircraft tyres have also been used on land speed vehicles,
such as the giant diesel trucks at Bonneville.

Anything put its weight on its tires, but contrary to cars, planes create lift, both supersonic and subsonic wings, so with planes as speed increases, lift increases, and tire load decreases

Not sure what you call massive braking forces, I´ve never seen a plane wich creates more deceleration under braking than any commuter. They brake hard, obviously, but not even close to any small car applying full brakes, let alone any of these ultra-hyper-sport cars

[Tommy Cookers]

.... "Reduce load..."
No, since Concorde as a supersonic delta design - put its weight on its tyres 'til lift-off,
& of course, on landing too - with instantaneous acceleration on touchdown

it seems that .....
at max wt (181 tons start of takeoff) Vr was 197 kt 227 mph IAS (ie true speed higher in places higher above sea level )
during the smooth rotation elevator would give downforce - but max tyre load would be at 227 mph IAS
if we believe Capt. Hutchinson saying that C full weight is on wheels fuselage-level (unlike other airliners)
ie design for best acceleration (having minimum wing drag ie no lift when fuselage-level) - and best braking

(rotation was to 13 deg to allow for engine loss - becoming 18 deg attitude in noise-abatement climb)
takeoff typically took 30 - 40 sec (11 - 13 sec in continuation training !)
C tyres didn't have a great record (Air France threw a tread causing fire and dubious 3 engine flight from the USA to France ?)

250 mph was apparently the 'safe' tyre limit for eg F105 F106 and F104 (this '240 kt' dead-engine landing)
shuttle touchdown 215 mph, SR71 242 mph, X15 similar
iirc Bob Hoover landed an F100 at 325 or so (the opening footage in the '6 million dollar man' thing)

btw pilots touch down with a deliberate bump on wet runways - the extra force helps wheels spin up and ABS to work