I am constantly baffled by the people taking that demo at face value.
That's not a real car. It's a hollow shell shaped like a car. The speed and precision it moves entirely suggest a lightweight object, especially since we don't see any flames or other indication of high powered jet fuel coming out of those nozzles.
It is physically impossible for a 1.5 ton vehicle to make that sort of leap with jets with that little buildup and that little apparent power. Momentum is a BITCH. Think about how much time it takes to get your car up to speed, or make a quick turn. The math ain't mathin'.
Questions of street legality or even entering any sort of production model aren't even in the picture here. This was an expensive tech demo of a fancy toy that isn't even a car, and they're trying to pretend it's an actual car. Think about the fact that they never show you the interior of it either immediately before or immediately after it does the stunts. That's because there's nothing inside.
If you believed it was real, you fell for the con.
There is a difference between a compressed-air thrust system and a combustion jet engine. Weight still matters, but with enough thrust, a heavy car can move quickly, kind of like an F-35. It's an oversimplification, but the physics is similar to F = ma, and the mass is nearly fixed in this case
Car and Driver said 250 kg of air stored in 600 tanks. At roughly 690 bar (10,000 psi), that density sounds right to me. Assume the exhaust velocity is 350 m/s, which is typical for cold gas. The total impulse is 250 kg x 350 m/s~87.5 kN·s.
A 1.5 ton car is about 14.7 kN (1500kg x 9.81). The semi is around 4.1 m tall, and the car appears to jump well above it. Say the jump reached 10 m. Clearing a 10m height needs a launch speed of about 14m/s, since v = (2 x 9.81 x10)^1/2. That takes a net impulse of about 21 kN·s (1500 kg x 14 m/s). The system has roughly four times that before accounting for losses.
At 350 m/s, the full 87.5 kN·s would hold up the car's weight for about 6 s (87.5/14.7). Gravity losses, steering and flipping take a share of that. A short, high-thrust jump is well within what the tanks can deliver, so I would say the jump is physically possible.
Not the target customer tho. But it was fun doing the calc.....
There won't be any. It was a tech demo. The version of this that they will sell to a dozen friends of Elon won't do anything like this, this thing was probably all tanks inside. The version that an average rich consumer could go buy won't have jets at all
All of this is public information. Bottom trim has no boost, middle trim has the rear thrusters with a 200L COPV, top trim has all the boosters with a 600L COPV.
The boosts are really a one trick pony though. The math involved shows it can only do a few of these moves and then will need the tank refilled. Especially a 0-60. I struggle to see how a 10,000 psi air tank sitting right behind the driver could ever be road legal.
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u/TheCerpent 19h ago
I am constantly baffled by the people taking that demo at face value.
That's not a real car. It's a hollow shell shaped like a car. The speed and precision it moves entirely suggest a lightweight object, especially since we don't see any flames or other indication of high powered jet fuel coming out of those nozzles.
It is physically impossible for a 1.5 ton vehicle to make that sort of leap with jets with that little buildup and that little apparent power. Momentum is a BITCH. Think about how much time it takes to get your car up to speed, or make a quick turn. The math ain't mathin'.
Questions of street legality or even entering any sort of production model aren't even in the picture here. This was an expensive tech demo of a fancy toy that isn't even a car, and they're trying to pretend it's an actual car. Think about the fact that they never show you the interior of it either immediately before or immediately after it does the stunts. That's because there's nothing inside.
If you believed it was real, you fell for the con.