RE: Time For Tea: Mini does a backflip
Discussion
hornet said:
How are we defining "car" here, as this has been done previously in an assortment of buggy type vehicles. Still impressive mind you, not going to argue that!
And plenty of monster trucks, admittedly mostly landing back on the take-off spot, and some less than successfully! 
http://www.youtube.com/watch?v=IXkJxCgWqHo
Edited to add: beaten to it!
ruaricoles said:
And plenty of monster trucks, admittedly mostly landing back on the take-off spot, and some less than successfully!
http://www.youtube.com/watch?v=IXkJxCgWqHo
Edited to add: beaten to it!
This is the craziest one I've found :-http://www.youtube.com/watch?v=IXkJxCgWqHo
Edited to add: beaten to it!
http://www.youtube.com/watch?v=L-l-hvIJEYE
Suspect the second was accident rather than design, but even so!
Super Slo Mo said:
Turbocharger said:
Ignoring the Mini PR for a moment, that's a very difficult stunt technically. As soon as the front axle leaves the ramp the rear suspension tries to unload which rotates the car nose-downward. To keep it turning backward needs a big rate of rotation on the ramp (which is very curved: check) and a very stiff rear spring rate (probably, hard to tell from the vid).
This is why most cars land nose-first when you jump them - though I've often wondered why Volvo engineered Mrs T's S40 to land tail-first.
Now, I'm more than happy to be corrected here, but I understood that a vehicle's attitude in mid-air had more to do with the inertia of the rotating masses (engine/gearbox/wheels) than the angle of the departure ramp. This is why most cars land nose-first when you jump them - though I've often wondered why Volvo engineered Mrs T's S40 to land tail-first.
In a nutshell, if you reduce engine revs in mid-air (as most people naturally do), the car tries to rotate about the slowing wheels (and engine/gearbox), due to Newton's 3rd law, that being that each action (the slowing of the wheels) has an opposite re-action (the rotation of the car in the opposite direction). So to land a car on its' tail would simply require a bootful of throttle during the flight (damage to transmission etc notwithstanding on landing).
I was also given to believe that moto-x riders use this principle to control their bike's attitude when going over big jumps.
Might all be an urban myth though.
But, on a bike with a small light engine and where the wheels and tyres are a much large percentage of the overall mass, I can understand how it works.
In a car, I would have expected the wheels to have less effect as they are a small proportion of the mass. Pus, how would this work with 4WD? Would accelerating the rotational mass at both ends of the car in the same direction cancel each other out? Or amplify it? Is the engine so much larger and heavier than the wheels won't overcome the reciprocating mass of the pistons in nay case?
Hmmm...
Manks said:
dod said:
Why so little love for the Countryman??
Don't know. We have one as a pool car and it's great.I'm not a Mini fanboy by any stretch but I do currently have a Mini Countryman Cooper S All4. Its not the best handling, best riding (run flats really don't help, fastest (it feels a lot slower than it's numbers suggest) and it is a lot worse on fuel as with most modern cars than indicated.
Buuuut it never fails to put a grin on my face, the exhaust note is nice but not too shouty, unless in sport where you get various pops and bangs when you lift off the throttle(engine is unbelievable noisey though at idle with various clatters and ticking noises) The steering is really quick racked and direct and coupled with the on demand awd system, you can point the nose where you want and the car stays perfectly neutral on the throttle with the awd system shunting power around with all the nanny systems on. It gets a lot more playful with them off and iv'e been having a lot fun in the snow over the last couple of months.
The car is really practical aswell. It has bags of rear leg room and the boot is plenty big enough for 2+1 little'un.
I still think it looks funny even now but how many of the haters on here have thrown one down your local favorite road? You'd end up grinning but you'd never figure out why. It's like kind of car.
Reardy Mister said:
That's exactly how free style MX riders change the attitude of the bike in the air. I *believe* Eddie Kidd was the first person to figure this out.
But, on a bike with a small light engine and where the wheels and tyres are a much large percentage of the overall mass, I can understand how it works.
In a car, I would have expected the wheels to have less effect as they are a small proportion of the mass. Pus, how would this work with 4WD? Would accelerating the rotational mass at both ends of the car in the same direction cancel each other out? Or amplify it? Is the engine so much larger and heavier than the wheels won't overcome the reciprocating mass of the pistons in nay case?
Hmmm...
The wheels are fairly heavy in a car, obviously not as great a proportion of the overall weight (I'm assuming, MX bike wheels are not heavy), and the bike wheels are of fairly large diameter, so amplify the effect. But, on a bike with a small light engine and where the wheels and tyres are a much large percentage of the overall mass, I can understand how it works.
In a car, I would have expected the wheels to have less effect as they are a small proportion of the mass. Pus, how would this work with 4WD? Would accelerating the rotational mass at both ends of the car in the same direction cancel each other out? Or amplify it? Is the engine so much larger and heavier than the wheels won't overcome the reciprocating mass of the pistons in nay case?
Hmmm...
There will have to be some effect though, otherwise we've figured out how to break the laws of physics.
In terms of 4WD, it'll have a bigger effect, all four wheels have a significant amount of inertia, and the car will want to rotate around each wheel in the same direction. I suspect in terms of the engine, it's the rotational inertia of the flywheel that will have the effect, as the engine will want to rotate in the engine bay in any case.
dukebox9reg said:
Manks said:
dod said:
Why so little love for the Countryman??
Don't know. We have one as a pool car and it's great.As for "Alec Issigonis turning in his grave", I cannot imagine that he was overly delighted with what happened to his design whilst he was alive. Mini Clubman Countryman anyone?
The old Mini was a great piece of design when it launched, but by the time the last one rolled off the assembly line it was an anachronism. It was too small and starting to look dangerous in a world where everything else was growing larger. Even in their heyday they were hardly the paragon of safety. My best mate was killed in one and I had more scrapes in Minis than any other car.
On the subject of scrapes, I am reminded of the many quality issues associated with the old Mini. I still have scar tissue on my knuckles from replacing bypass hoses and were it not for my luscious head of hair my scalp would tell the tale of a million subframe welds. Minis left the factory rusting and most of them fairly swiftly served to underwrite Isopon's profitability due to their appetite for P40 and P38.
They were fun though, no one can deny that.
The "new" Mini if we can call it that for a moment is something of a triumph in my opinion. It is a fun car, well made and it is contemporary whilst relentlessly leveraging its (admittedly tenuous) links with the original Mini. Yes, that dreadful estate model with the rear door on the wrong side was a cockup of monumental proportions and I can never see one without thinking it looks like a hearse for dogs. But the Countryman is superb. It has charisma, drives well, is robust and we can sling everything from customers to joinery tools into its commodious interior and a 3-monthly valet brings it up as good as new.
Super Slo Mo said:
The wheels are fairly heavy in a car, obviously not as great a proportion of the overall weight (I'm assuming, MX bike wheels are not heavy), and the bike wheels are of fairly large diameter, so amplify the effect.
There will have to be some effect though, otherwise we've figured out how to break the laws of physics.
In terms of 4WD, it'll have a bigger effect, all four wheels have a significant amount of inertia, and the car will want to rotate around each wheel in the same direction. I suspect in terms of the engine, it's the rotational inertia of the flywheel that will have the effect, as the engine will want to rotate in the engine bay in any case.
Didn't Peugeot have this problem in the eighties with the Group B 205 T16? I think the engine was transversely mid-mounted, so whenever it left the ground and the revs rose, the momentum of the crankshaft could upset trajectory of the car. If memory serves me well, they enlisted the help of Aerospatiale to correct this using aerodynamics.There will have to be some effect though, otherwise we've figured out how to break the laws of physics.
In terms of 4WD, it'll have a bigger effect, all four wheels have a significant amount of inertia, and the car will want to rotate around each wheel in the same direction. I suspect in terms of the engine, it's the rotational inertia of the flywheel that will have the effect, as the engine will want to rotate in the engine bay in any case.
74merc said:
Didn't Peugeot have this problem in the eighties with the Group B 205 T16? I think the engine was transversely mid-mounted, so whenever it left the ground and the revs rose, the momentum of the crankshaft could upset trajectory of the car. If memory serves me well, they enlisted the help of Aerospatiale to correct this using aerodynamics.
I don't know. Sounds plausible though.PascalBuyens said:
filski666 said:
Didn't Rhys Millen do a backflip in car a couple of years ago?
http://www.youtube.com/watch?v=gDsdhUesC2IHe failed on his actual run though...
Super Slo Mo said:
In terms of 4WD, it'll have a bigger effect, all four wheels have a significant amount of inertia, and the car will want to rotate around each wheel in the same direction. I suspect in terms of the engine, it's the rotational inertia of the flywheel that will have the effect, as the engine will want to rotate in the engine bay in any case.
I seem to recall that the Group B 205 T16 had noticeable engine-based responses on jumps and yumps, due to the centrally mounted, transverse engine design meaning that throttle on/off behaviour changed the attitude of the car.Anyone recall more details of that?
Oh and heres Maximum Destruction attempting a Double backflip.
http://youtu.be/5ZN0vbZGW7E
http://youtu.be/etaDFhGDfcY
http://youtu.be/5ZN0vbZGW7E
http://youtu.be/etaDFhGDfcY
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