RE: 331mph Tuatara is world's fastest production car
Discussion
Kawasicki said:
I have done some high speed tests. A major concern beforehand was that the tyres were correctly balanced and had low force variation. If during the test I noticed increased vibrations I would stop the test. It’s a great warning signal.
Regarding rubber properties I remember being fascinated to learn that sometimes extra load versions of tyres have actually less material in them than the normal version...why?...to reduce heat build up due to hysteresis and to promote cooling by increasing the area that can radiate the heat.
You see this in F1 races (probably others too I assume) where they struggle to keep heat in the tyres as the rubber wears for exactly this reason, insufficient movement within the material to generate the heat needed.Regarding rubber properties I remember being fascinated to learn that sometimes extra load versions of tyres have actually less material in them than the normal version...why?...to reduce heat build up due to hysteresis and to promote cooling by increasing the area that can radiate the heat.
Anyway, I still contend that no matter how good a drivers' car it is, it would be a better one if for the version they sell they limit it to 220mph or thereabouts and then pick the best setup from there.
Kent Border Kenny said:
Kawasicki said:
I have done some high speed tests. A major concern beforehand was that the tyres were correctly balanced and had low force variation. If during the test I noticed increased vibrations I would stop the test. It’s a great warning signal.
Regarding rubber properties I remember being fascinated to learn that sometimes extra load versions of tyres have actually less material in them than the normal version...why?...to reduce heat build up due to hysteresis and to promote cooling by increasing the area that can radiate the heat.
You see this in F1 races (probably others too I assume) where they struggle to keep heat in the tyres as the rubber wears for exactly this reason, insufficient movement within the material to generate the heat needed.Regarding rubber properties I remember being fascinated to learn that sometimes extra load versions of tyres have actually less material in them than the normal version...why?...to reduce heat build up due to hysteresis and to promote cooling by increasing the area that can radiate the heat.
Anyway, I still contend that no matter how good a drivers' car it is, it would be a better one if for the version they sell they limit it to 220mph or thereabouts and then pick the best setup from there.
2manycars said:
Oli is a good friend of mine and I was with him on Tuesday at the Michelin Supercar Driver event at Donington.
I’ve read on here people saying where do you get a 7 mile stretch to get up to 300mph. This is correct but as Oli said “it wasn’t the speed that was hard, getting to 300mph was quite easy’ it was the slowing down that was hard”.
He said that he had to slowly decrease his pressure on the accelerator a bit at a time. That after he hit the 331mph he started to lift off bit by bit (which is pretty hard to do with all that adrenaline pumping through your body), he said he was about 40% lifted off when he thought great I must be doing about 150-180mph, he was still around the 285mph mark. For him he said the scariest part was if he decreased his speed too much then he’d just have spun out. After the winds started to pick up he decided to call it a day, and I don’t blame him, especially with his daughter on the way. Oli is a great guy and a fantastic driver who takes pretty much everything in his stride but after that run even he said it was extreme. I just looked at him like he was suffering from delirium, what a guy, what a nutter!!!
I have no comprehension of what it must take from a mental point of view to be able to get over the inherent fear/self preservation that must come hand in hand when pushing something with so much associated risk involved. I know full well that I wouldn’t have what it takes, even if I had the talent, so hats to anyone who does have strength to ignore the negative possibilities just long enough to make these things happen.I’ve read on here people saying where do you get a 7 mile stretch to get up to 300mph. This is correct but as Oli said “it wasn’t the speed that was hard, getting to 300mph was quite easy’ it was the slowing down that was hard”.
He said that he had to slowly decrease his pressure on the accelerator a bit at a time. That after he hit the 331mph he started to lift off bit by bit (which is pretty hard to do with all that adrenaline pumping through your body), he said he was about 40% lifted off when he thought great I must be doing about 150-180mph, he was still around the 285mph mark. For him he said the scariest part was if he decreased his speed too much then he’d just have spun out. After the winds started to pick up he decided to call it a day, and I don’t blame him, especially with his daughter on the way. Oli is a great guy and a fantastic driver who takes pretty much everything in his stride but after that run even he said it was extreme. I just looked at him like he was suffering from delirium, what a guy, what a nutter!!!
Are you still enjoying the LFA by the way? I think even now that it would still be top if my list if I suddenly were in the position to be able to pick any car.
Max_Torque said:
Kawasicki said:
Good questions!
The tyre pressures for high speed running (at least on curved/banked tracks) are selected to avoid the tyres falling apart (reliably support the weight of the car, avoid any extreme hot spots on the tread area) and obviously to steer/handle ok.
By supporting the weight of the car, then yes, definitely a heavier car is a greater challenge than a lighter car...but... the pressures in the tyres will be raised though to give about the same vertical deflection that you would also have with a lighter car. You can’t go too crazy because you still need ok steering and you need to spread the work across a sufficient amount of tread (you need a fairly normal contact patch).
I didn’t mention setting pressures to allow low rolling resistance, as high rolling resistance, means a lot of energy absorbed by the tyre...which is not what you want...so low rolling resistance is sort of a given for tyres tuned/set up for high speed runs.
Heat and centrifugal force are the risks. Heat is reduced by reducing deflection, reducing the energy required to deflect, reducing scrub/slip angles and allowing cooling. Tyres are weird sometimes, you can get tiny hot spots at the edges of the belts that cause the rubber only there to breakdown (turn to black crumbs)... and that sets of a chain of events that cause the tyre to quickly fail.
Worth noting that as speed increases the power to drive the car through the air at that speed goes up (by the cube of speed actually) so the tyres also have to be able to transmit that tractive effort to the road, so tyre load is significant from that factorThe tyre pressures for high speed running (at least on curved/banked tracks) are selected to avoid the tyres falling apart (reliably support the weight of the car, avoid any extreme hot spots on the tread area) and obviously to steer/handle ok.
By supporting the weight of the car, then yes, definitely a heavier car is a greater challenge than a lighter car...but... the pressures in the tyres will be raised though to give about the same vertical deflection that you would also have with a lighter car. You can’t go too crazy because you still need ok steering and you need to spread the work across a sufficient amount of tread (you need a fairly normal contact patch).
I didn’t mention setting pressures to allow low rolling resistance, as high rolling resistance, means a lot of energy absorbed by the tyre...which is not what you want...so low rolling resistance is sort of a given for tyres tuned/set up for high speed runs.
Heat and centrifugal force are the risks. Heat is reduced by reducing deflection, reducing the energy required to deflect, reducing scrub/slip angles and allowing cooling. Tyres are weird sometimes, you can get tiny hot spots at the edges of the belts that cause the rubber only there to breakdown (turn to black crumbs)... and that sets of a chain of events that cause the tyre to quickly fail.
It will be interesting to read the views of the more informed folks on here once more of the technical details emerge regarding this car and how it able to do what has done, even if I completely fail to understand most of that too!
gigglebug said:
I have no comprehension of what it must take from a mental point of view to be able to get over the inherent fear/self preservation that must come hand in hand when pushing something with so much associated risk involved. I know full well that I wouldn’t have what it takes, even if I had the talent, so hats to anyone who does have strength to ignore the negative possibilities just long enough to make these things happen.
Are you still enjoying the LFA by the way? I think even now that it would still be top if my list if I suddenly were in the position to be able to pick any car.
Yeah I wouldn’t even be able to comprehend what it must feel like to do that sort of speed without thinking “am I going to die?”Are you still enjoying the LFA by the way? I think even now that it would still be top if my list if I suddenly were in the position to be able to pick any car.
Still loving the LFA thanks, it’s such a well planted car, especially on track. However after racing against a few Chirons, F50’s and a couple of Pagani’s at Donington on Tuesday I’ve completely cooked the brakes, or the brake lines. I’ve just got a constant beeping going on and a ‘brake failure’ warning on the dash. Anyway I’ll stick in it for a service before we do the next shootout of my LFA vs CGT, the best of the V10’s. Anyway don’t won’t to derail this thread, all that V10 action will be over on my thread soon.
2manycars said:
Yeah I wouldn’t even be able to comprehend what it must feel like to do that sort of speed without thinking “am I going to die?”
Still loving the LFA thanks, it’s such a well planted car, especially on track. However after racing against a few Chirons, F50’s and a couple of Pagani’s at Donington on Tuesday I’ve completely cooked the brakes, or the brake lines. I’ve just got a constant beeping going on and a ‘brake failure’ warning on the dash. Anyway I’ll stick in it for a service before we do the next shootout of my LFA vs CGT, the best of the V10’s. Anyway don’t won’t to derail this thread, all that V10 action will be over on my thread soon.
Good stuff, sounds like plenty of fun. Well, apart from the brakes of course!Still loving the LFA thanks, it’s such a well planted car, especially on track. However after racing against a few Chirons, F50’s and a couple of Pagani’s at Donington on Tuesday I’ve completely cooked the brakes, or the brake lines. I’ve just got a constant beeping going on and a ‘brake failure’ warning on the dash. Anyway I’ll stick in it for a service before we do the next shootout of my LFA vs CGT, the best of the V10’s. Anyway don’t won’t to derail this thread, all that V10 action will be over on my thread soon.
I’ll keep an eye on the thread for the V10’s, there will be many like myself who will have them both around the top of their all time lists.
Well this is interesting, Shmee150 has actually done some digging into the run and is now throwing shade on its validity. I am no fan of his but this might actually be a decent bit of work, check out the video:
https://www.youtube.com/watch?v=3daTG4_JS_4
https://www.youtube.com/watch?v=3daTG4_JS_4
Streetrod said:
Well this is interesting, Shmee150 has actually done some digging into the run and is now throwing shade on its validity. I am no fan of his but this might actually be a decent bit of work, check out the video:
https://www.youtube.com/watch?v=3daTG4_JS_4
Yea seems to me that the video shown was either not the actual record breaking run or this was completely faked.https://www.youtube.com/watch?v=3daTG4_JS_4
Bit annoying Shmee posts a video like he discovered it three days after another video does the rounds: https://www.youtube.com/watch?v=PLoFKcH7zGo&fe...
jimmsy said:
Bit annoying Shmee posts a video like he discovered it three days after another video does the rounds: https://www.youtube.com/watch?v=PLoFKcH7zGo&fe...
He doesn't claim to have discovered it at all and in fact appears to have the video you have provided showing on the laptop in his presentation at one point. He freely admits to having had gained information and opinions from others in an attempt to answer his own questions.SantaBarbarian said:
Would this man lie to you?
It has been a long development time for this car. Maybe a desperate last stab at generating income to stay afloat. Shame, because it is a pretty car. I'll take the orange one if they want to unload it for cheap.
Wouldn't trust what this knock-off Christian von Koenigsegg has to say.It has been a long development time for this car. Maybe a desperate last stab at generating income to stay afloat. Shame, because it is a pretty car. I'll take the orange one if they want to unload it for cheap.
MikeGalos said:
You think a car that can go 300 mph has to go 300 mph?
Perhaps you think cars that go on public roads should only be ones that can't go above whatever national speed limit there is in your country?
Please, expound on your amusing idea. I'm sure we'd all love to hear more.
What's to expand?Perhaps you think cars that go on public roads should only be ones that can't go above whatever national speed limit there is in your country?
Please, expound on your amusing idea. I'm sure we'd all love to hear more.
If your country has a maximum speed limit for it's public roads of say, 75MPH, there's no reason or justification to make, market and sell cars capable of 300mph.
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