Let’s say I had access to a comvenient mountain next to a plain, and a lot of money.
Would it be possible to beuild a real-life track complete with a loop and a jump, like the plastic Hot Wheels track I had then I was a kid? And, if so, would existing standard road cars be able to accelerate and/or roll, and survive the g-forces, sufficiently well to make it through the loop and across the jump?
I’m imagining something like a cross between the Olympic ski jumps at Canmore and the racetrack at Mosport.
Would it be powered only by gravity? There is significantly more friction in a standard car than a Hot Wheels car. The tires, axle, transaxle, and transmission are all going to be slowing the car down (well, not the transmission if you’re doing it in neutral).
Building the loop would be difficult, but not impossible. It would most likely have to be made in sections, and hoisted into place (I don’t know of a process that’s been perfected to lay asphault upside-down).
Surviving the G forces would not be a problem, cars are designed to take some pretty big bumps. Replacing the shocks with the new computer controled variable damping shocks would help.
Without a rocket or other non-wheel based propulsion, I can’t see a drastically specialized car gaining enough momentum to make the loop.
My guess for the radius would be 20 meters, though.
I suppose we could have the car accelerate down the hill if necessary.
The loop could be built using roller-coaster strucural-support techhiques, suitably scaled-up and strengthened. I see no reason to use asphaly for the track surface, especially in the loop; reinforced-concrete deck segments could be built to hang upside-down, couldn’t they? If not, the deck in the upper part of the loop would have to be steel, possibly with a grippy coating.
In the hot wheels universe, the wheels are fixed and the car is restrained within the track by the track sides. In real life, that would add too much friction. So you would need a driver, presumably, to keep the thing on track.
I’ve often wondered what the speeds and pressures would translate to- those little cars take that loop awfully fast.
In the early-90s Atari video game Hard Drivin’, you could loop at around 85 mph. It took a couple seconds to do so and it felt spectacular considering that the rest of the physics seemed fairly accurate.
As long as you dont get stuck on any treadmills, I think it’s possible. As has been said before though, I think it might require some rocket-based propulsion.
I don’t see how this would be any different from a roller coaster. A car should be substantially lighter than a roller coaster train, so I don’t think you would even need to strengthen the loop… just widen it. And roller coasters can loop at 50-60mph… the fact that they’re held to the track is just for safety, as they can make the loop on velocity alone (if they’re full enough… sometimes going through loops in an empty car feels funny). So someone can do some quick math to find out how long a 3000 lb car would take to accelerate to, say 70 mph on a 60 degree incline (shouldn’t be very far, less if it’s powered) and we’d be good.
The jump would be much more difficult, at least if you wanted to drive away afterwards… contrary to what the movies say, car suspensions don’t like going from 0 load to 10x the weight of the car very quickly, so you’d have to have the catching end of the ramp be at a very precise angle to follow the parabolic path of the car in flight. However, the mass of the car and it’s ramp exit speed would have to be very carfully controlled, the latter of which might be difficult coming out of a loop.
I had a radio controlled car that would loop under it’s own power inside of a 55 gallon drum laid on it’s side. It was 1/12th scale. It would go until the batteries got low.
Back in the 70’s at Cascade Mountain in Baraboo, WI. they had this weird ride you could go on in the summer called the Mountain Coaster. It was a one man little cart.
Anyway, the track and set up had always reminded me of a hotwheels track. Especially the orange colored sections. You’d have to see it to understand, but I can’t find any pictures on-line. There are mountain coaster pix on-line, but they’re not the same as the one I remember. It’s been gone for like 20 years now.
But it was fun and I think your idea could have commercial possibility.
That sounds like the alpine slide at Chestnut Mountain in Galena Il. It’s a cement track and kinda looks like a bobsled track. You sit in a one person cart and your only control is how much brake pressure you apply. Here’s an aerial view of the ski resort. The lighter colored line that goes from the middle on the right to the upper left of the resort is the slide.
This is alot of fun, but if you take a turn too fast, you can fly off the track. The stuff the track is made of will rip the skin off your arms and legs if you wear shorts/t shirt. Don’t ask me how I know.
What do you do when you track splits apart and your car flies off of the turn? Or the gigantic King Kong ape smashes your car! You are wise to ask our assistance before you go out there and build this thing!
I would suggest several of these to defend against giant apes.
And maybe one of these to check the track over every now and then.
My mechanics days are long behind me, but it seems like this is the kind of thing one could calculate. Centripedal force necessary to overcome force due to gravity for long enough to keep the car on the surface of the loop at the top, with potential variables being the diameter of the loop, the speed of entry, the weight of the car, the coefficient of friction, etc. The OP stipulates a regular old car, which I think would eliminate souped-up suspensions or even disconnecting the transmission.
Sunspace, is there a big hill on your drive to work?
I calculate that to match gravity on a 25 meter loop, you’d need to be travelling at 15.7 m/s at the top of the loop. Obviously you’re going to need a little more speed to maintain traction and you’ll lose some speed on the first half of the loop, but it seems easily doable. On a 50 meter loop, you’d need to be going 22.1 m/s, still probably doable even though you’ll lose more speed on the incline.
If you make the loop diameter too big, that also makes it a long way around and consequently a long way up the first inclined section - then the car may not have enough power to keep going and complete the loop. If you make the diameter too small, then the car hits it at speed and is deflected upwards into the loop with forces that may be destructive.
I think you’d need a car with very strong, stiff suspension and possibly solid tyres. I also think it might work best if the loop isn’t actually circular - I think a sort of helix that starts off shallow, but with a curvature that tightens the further around you are - that way, even though you’re slowing down, the tighter radius would compensate by increasing the force holding you on the track.
