[NA]Car jump gone wrong[NA]

In high school we called that "having more balls than brains!"
:goofy:

Then we'd say "how 'bout we don't and say we did?"
 
Same old mistakes. You can't stop flying it until it is tied down.:lol:
 
I can just hear Don Adams from 'Get Smart' saying, "missed it by this much!"
 

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Wow, looks like he needs to put an elevator on that car to control his pitch.

I wonder if a big adjustable pitch spoiler could have helped him out...
 
Don't try it, Dave.
 
Somedudeintn said:
Wow, looks like he needs to put an elevator on that car to control his pitch.

I wonder if a big adjustable pitch spoiler could have helped him out...
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Yep, that's what they forgot was the spoiler on the back, or at least some ballast.
 
Needs to check weight and balance, CG too far forward. :lol:
 
I never understood why they never balance the cars for this. Yeah, more weigh requires more power, but every stunt jump you see on TV or in movies, or even these, the car always pitches way too far forward.
 
You have the ability to control your pitch on a dirtbike either by adding gas or stomping on the rear brake. Wonder if he could have done the same in the car.
 
Cpt_Kirk said:
You have the ability to control your pitch on a dirtbike either by adding gas or stomping on the rear brake. Wonder if he could have done the same in the car.
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No, that's what sucks about doing this stuff with front wheel drive, besides, the wheels on a car have much less comparative inertia to the moment of the chassis when compared to the leverage available on a motorcycle. With cars you have to make sure you have the CG just right.
 
1) More weight in either end won't make it rotate since both ends of the vehicle are in free fall and will accelerate at the same rate (9.81 m/s^2 or, if you prefer, 32.3 ft/sec^2).

2) Adding weight to the FRONT and some aerodynamics to the rear would make the vehicle more aerodynamically stable and keep it pointed more in the direction of travel.

3) The front wheels leave the ramp first and start falling first - this sets up a rotation that will not be stopped without some aerodynamic work that would undo the car like appearance. Motorcycles have enough torque at the rear wheels to essentially wheelie off the end of the ramp to avoid this, but that is much harder in a car.
 
Capt. Geoffrey Thorpe said:
1) More weight in either end won't make it rotate since both ends of the vehicle are in free fall and will accelerate at the same rate (9.81 m/s^2 or, if you prefer, 32.3 ft/sec^2).

2) Adding weight to the FRONT and some aerodynamics to the rear would make the vehicle more aerodynamically stable and keep it pointed more in the direction of travel.

3) The front wheels leave the ramp first and start falling first - this sets up a rotation that will not be stopped without some aerodynamic work that would undo the car like appearance. Motorcycles have enough torque at the rear wheels to essentially wheelie off the end of the ramp to avoid this, but that is much harder in a car.
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It's impossible in a FWD car, that was his big mistake.
 
Capt. Geoffrey Thorpe said:
1) More weight in either end won't make it rotate since both ends of the vehicle are in free fall and will accelerate at the same rate (9.81 m/s^2 or, if you prefer, 32.3 ft/sec^2).

2) Adding weight to the FRONT and some aerodynamics to the rear would make the vehicle more aerodynamically stable and keep it pointed more in the direction of travel.

3) The front wheels leave the ramp first and start falling first - this sets up a rotation that will not be stopped without some aerodynamic work that would undo the car like appearance. Motorcycles have enough torque at the rear wheels to essentially wheelie off the end of the ramp to avoid this, but that is much harder in a car.
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Then why on Mythbusters when they dropped a car from a 'flat' position did it nose over?
 
Capt. Geoffrey Thorpe said:
1) More weight in either end won't make it rotate since both ends of the vehicle are in free fall and will accelerate at the same rate (9.81 m/s^2 or, if you prefer, 32.3 ft/sec^2).
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The model you propose is just a bit on the simplistic side...
 
EdFred said:
Then why on Mythbusters when they dropped a car from a 'flat' position did it nose over?
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See 2) above. The CG will be forward of the "center of pressure", but not enough to make it as stable as an arrow.

If you add enough weight to the rear, you can make it aerodynamically stable flying backwards, but I don't think that would be a good plan.
 
Capt. Geoffrey Thorpe said:
See 2) above. The CG will be forward of the "center of pressure", but not enough to make it as stable as an arrow.

If you add enough weight to the rear, you can make it aerodynamically stable flying backwards, but I don't think that would be a good plan.
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But if you put enough weight in back it will keep it from pitching over like they always do. All you really want its to slow the pitch. Right now they always pitch too far. The "flight" isn't long enough to worry about aerodynamic stability, it has to be countered with a CG shift.
 
Capt. Geoffrey Thorpe said:
See 2) above. The CG will be forward of the "center of pressure", but not enough to make it as stable as an arrow.

If you add enough weight to the rear, you can make it aerodynamically stable flying backwards, but I don't think that would be a good plan.
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The only way to make a car aerodynamically stable in a jump is to change the aerodynamics. There are two basic ways it's done, either closing off and fairing under the engine compartment (moderately effective on short jumps) or using a spoiler device on the back. It all depends on what the director wants to see or not. Ballast is typically only used in the very back to affect the balance during the time the back wheels are on and the front wheels are off the ramp, but it only makes a difference if you are driving the rear axle, and typically is only used in weird constructions. It's rare to see much ballast.
 
The marks are in:

6.5 for required skills.

7.3 for artistic merit.

Seems the judges didn't like him backing off a bit just before the ramp. That's a clear point deduction, and the judges were pretty harsh on him there. The air time was good, and he got a little bonus for his glance to the side in the air. He also scored well with the 'rag doll' move on touch down, but in the end I don't think this will hold up for a podium.
 
I gave him a small bonus for the double rotation between touches, but yeah, no podium.
 
Car is JUNK now........

But.......
The motor sounded REAL strong.....:yes::):):):)
 
Clark1961 said:
Yes and he finished inverted. The rules clearly state that the final position must be upright, not face down.
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If it would have ended on the tires and drove away, that would have been the most awesome jump on record.
 
I agree, an elevator (or any pitch control device) would have helped. It was the nose-over that caused the trouble. Had he kept the nose high, he would have stuck the landing.
I take it they didn't do W&B calculations (no joke) to determine whether the car would nose-dive in free flight. Some people don't care for physics, they just want to fly. :)
 
BigBadLou said:
I agree, an elevator (or any pitch control device) would have helped. It was the nose-over that caused the trouble. Had he kept the nose high, he would have stuck the landing.
I take it they didn't do W&B calculations (no joke) to determine whether the car would nose-dive in free flight. Some people don't care for physics, they just want to fly. :)
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They did not take several critical factors into consideration, just the simple ballistics.
 
Henning said:
They did not take several critical factors into consideration, just the simple ballistics.
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Reminds me of the hacks called Mythbusters. They too usually attempt crazy stunts without understanding the background, physics and other factors. And especially: safety last!! :D
 
BigBadLou said:
Reminds me of the hacks called Mythbusters. They too usually attempt crazy stunts without understanding the background, physics and other factors. And especially: safety last!! :D
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Never let safety stand in the way of fun and a good video.:D
 
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