Bugatti breaks 300 mph barrier with a modified Chiron

Breaking news, useful data or technical highlights or vehicles that are not meant to race. You can post commercial vehicle news or developments here.
Please post topics on racing variants in "other racing categories".
Maritimer
Maritimer
22
Joined: Wed Sep 06, 2017 8:45 pm
Location: Canada

Re: Bugatti breaks 300 mph barrier with a modified Chiron

Post

Holm86 wrote:
Sun Oct 25, 2020 1:21 am
Morteza wrote:
Sat Oct 24, 2020 9:20 pm
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
MrMuffins
2
Joined: Sun Feb 11, 2018 5:50 am

Re: Bugatti breaks 300 mph barrier with a modified Chiron

Post

cheeRS wrote:
Sun Oct 25, 2020 3:08 am
humble sabot wrote:
Fri Oct 23, 2020 9:34 am
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.

User avatar
RZS10
153
Joined: Sat Dec 07, 2013 12:23 am

Re: Bugatti breaks 300 mph barrier with a modified Chiron

Post

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.
J.A.W.
92
Joined: Mon Sep 01, 2014 4:10 am
Location: Altair IV.

Re: Bugatti breaks 300 mph barrier with a modified Chiron

Post

humble sabot wrote:
Fri Oct 23, 2020 9:34 am
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')...
Dr Moreau sez..
"Who breaks the law... goes back to the House of Pain!"

Tommy Cookers
Tommy Cookers
543
Joined: Fri Feb 17, 2012 3:55 pm

Re: Bugatti breaks 300 mph barrier with a modified Chiron

Post

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
Last edited by Tommy Cookers on Mon Oct 26, 2020 4:12 pm, edited 1 time in total.

JRodrigues
JRodrigues
6
Joined: Tue Dec 06, 2011 4:19 pm

Re: Bugatti breaks 300 mph barrier with a modified Chiron

Post

Maritimer wrote:
Sun Oct 25, 2020 3:43 am
Holm86 wrote:
Sun Oct 25, 2020 1:21 am
Morteza wrote:
Sat Oct 24, 2020 9:20 pm
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
Just_a_fan
662
Joined: Sun Jan 31, 2010 7:37 pm

Re: Bugatti breaks 300 mph barrier with a modified Chiron

Post

J.A.W. wrote:
Mon Oct 26, 2020 8:50 am
humble sabot wrote:
Fri Oct 23, 2020 9:34 am
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. :wink:
Turbo says "Dumpster sounds so much more classy. It's the diamond of the cesspools." oh, and "The Dutch fans are drunk. Maybe"

J.A.W.
J.A.W.
92
Joined: Mon Sep 01, 2014 4:10 am
Location: Altair IV.

Re: Bugatti breaks 300 mph barrier with a modified Chiron

Post

Just_a_fan wrote:
Mon Oct 26, 2020 4:09 pm
J.A.W. wrote:
Mon Oct 26, 2020 8:50 am
humble sabot wrote:
Fri Oct 23, 2020 9:34 am
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. :wink:
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...
Dr Moreau sez..
"Who breaks the law... goes back to the House of Pain!"

JRodrigues
JRodrigues
6
Joined: Tue Dec 06, 2011 4:19 pm

Re: Bugatti breaks 300 mph barrier with a modified Chiron

Post

Image

Maritimer
Maritimer
22
Joined: Wed Sep 06, 2017 8:45 pm
Location: Canada

Re: Bugatti breaks 300 mph barrier with a modified Chiron

Post

JRodrigues wrote:
Mon Oct 26, 2020 4:00 pm
Maritimer wrote:
Sun Oct 25, 2020 3:43 am
Holm86 wrote:
Sun Oct 25, 2020 1:21 am


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.

User avatar
Holm86
231
Joined: Wed Feb 10, 2010 2:37 am
Location: Copenhagen, Denmark

Re: Bugatti breaks 300 mph barrier with a modified Chiron

Post


User avatar
humble sabot
26
Joined: Sat Feb 17, 2007 9:33 am

Re: Bugatti breaks 300 mph barrier with a modified Chiron

Post

J.A.W. wrote:
Tue Oct 27, 2020 8:42 am
......
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.
the four immutable forces:
static balance
dynamic balance
static imbalance
dynamic imbalance

J.A.W.
J.A.W.
92
Joined: Mon Sep 01, 2014 4:10 am
Location: Altair IV.

Re: Bugatti breaks 300 mph barrier with a modified Chiron

Post

humble sabot wrote:
Fri Oct 30, 2020 6:44 pm
J.A.W. wrote:
Tue Oct 27, 2020 8:42 am
......
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.
Dr Moreau sez..
"Who breaks the law... goes back to the House of Pain!"

User avatar
Andres125sx
355
Joined: Tue Aug 13, 2013 9:15 am
Location: Madrid, Spain

Re: Bugatti breaks 300 mph barrier with a modified Chiron

Post

J.A.W. wrote:
Fri Oct 30, 2020 10:04 pm
humble sabot wrote:
Fri Oct 30, 2020 6:44 pm
J.A.W. wrote:
Tue Oct 27, 2020 8:42 am
......
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
Tommy Cookers
543
Joined: Fri Feb 17, 2012 3:55 pm

Re: Bugatti breaks 300 mph barrier with a modified Chiron

Post

J.A.W. wrote:
Fri Oct 30, 2020 10:04 pm
.... "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
Last edited by Tommy Cookers on Sat Oct 31, 2020 11:04 pm, edited 3 times in total.