# Bonkers hypercar breaks 1/4 mile record at 7.97 seconds (car will be street legal...I think) **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [December 15, 2022, 8:13pm UTC](https://boards.straightdope.com/t/bonkers-hypercar-breaks-1-4-mile-record-at-7-97-seconds-car-will-be-street-legal-i-think/976609 "2022-12-15T20:13:55Z")\ **Posts on this page:** 11\ **Page:** 2
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [December 17, 2022, 10:19pm UTC](https://boards.straightdope.com/t/bonkers-hypercar-breaks-1-4-mile-record-at-7-97-seconds-car-will-be-street-legal-i-think/976609/21 "2022-12-17T22:19:24Z")
Here’s the driver trying to get out of the car from the OP’s video (queued to the right spot so only a few seconds of viewing necessary): [![](https://img.youtube.com/vi/TptzkkbC1vE/maxresdefault.jpg "I broke the 1/4-mile world record in this new HYPERCAR!") ](https://www.youtube.com/watch?v=TptzkkbC1vE) ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [December 17, 2022, 10:27pm UTC](https://boards.straightdope.com/t/bonkers-hypercar-breaks-1-4-mile-record-at-7-97-seconds-car-will-be-street-legal-i-think/976609/22 "2022-12-17T22:27:05Z")
Yes but at 7:20 the first driver pops right out. ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [December 17, 2022, 10:30pm UTC](https://boards.straightdope.com/t/bonkers-hypercar-breaks-1-4-mile-record-at-7-97-seconds-car-will-be-street-legal-i-think/976609/23 "2022-12-17T22:30:13Z")
Yeah…the 30-year-old fit guy. Leno is 72. But he loves cars so much it would not surprise me if he got one and just dealt with the hassle of getting in and out. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [December 17, 2022, 11:10pm UTC](https://boards.straightdope.com/t/bonkers-hypercar-breaks-1-4-mile-record-at-7-97-seconds-car-will-be-street-legal-i-think/976609/24 "2022-12-17T23:10:50Z")
> [@Chronos](#): > > is that you can’t just freely change the direction of the fan-force Ahh, I see that I actually misread you to start with. You were already accounting for the suction force, and were thinking about what to do with the excess airflow. I agree that with a CoF=1, it does not matter if you blow downward or opposite the direction of motion, and that you need \>1 for blowing downward to be significant. In any case, I think the effect is fairly negligible here. The Wikipedia page says the fan system is 60 kW. If the airflow is 50 m/s, that would be only 1.2 kN compared to the 10-20 kN given by the atmospheric pressure. And 50 m/s is a fairly slow air speed; in practice they’d probably need it to be much faster to keep the fan size reasonable. At 100 m/s, the thrust goes down to 0.6 kN. And that’s still assuming perfect efficiency. The video of the car shows fairly unsophisticated exhaust ports. They probably get some benefit from backfilling the low-pressure zone that you get at high speeds, but I don’t think they’re counting on any real thrust from the airflow. ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [December 17, 2022, 11:57pm UTC](https://boards.straightdope.com/t/bonkers-hypercar-breaks-1-4-mile-record-at-7-97-seconds-car-will-be-street-legal-i-think/976609/25 "2022-12-17T23:57:49Z")
[Here’s a clip of Jay Leno getting into his Mercedes 300SL](https://www.youtube.com/watch?v=I4uEk3AcY84). It’s got the same hump to crawl over. Go to 10:25 to see him get in. A 300SL is like a Spitfire fighter plane. You don’t get in it, you strap it on. He wouldn’t have a problem with this car. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [December 18, 2022, 1:48am UTC](https://boards.straightdope.com/t/bonkers-hypercar-breaks-1-4-mile-record-at-7-97-seconds-car-will-be-street-legal-i-think/976609/26 "2022-12-18T01:48:39Z")
> [@Dr.Strangelove](#): > > In any case, I think the effect is fairly negligible here. The Wikipedia page says the fan system is 60 kW. If the airflow is 50 m/s, that would be only 1.2 kN compared to the 10-20 kN given by the atmospheric pressure. And 50 m/s is a fairly slow air speed; in practice they’d probably need it to be much faster to keep the fan size reasonable. At 100 m/s, the thrust goes down to 0.6 kN. And that’s still assuming perfect efficiency. I haven’t watched the vids, so what follows may be totally off-base. As to KW, CFMs, etc., there’s one approach with fans pushing ambient air upwards to push the car downwards via “F=Ma” and “equal and opposite reaction.” IOW, vertically oriented jets. Another approach is to use the fans to evacuate the airspace under the car and let the differential pressure vs. the ambient atmosphere stick the car to the road like a giant (but semi-leaky) suction cup. IMO the relative effectiveness of Plan B is vastly higher than Plan A. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [December 18, 2022, 1:52am UTC](https://boards.straightdope.com/t/bonkers-hypercar-breaks-1-4-mile-record-at-7-97-seconds-car-will-be-street-legal-i-think/976609/27 "2022-12-18T01:52:58Z")
> [@LSLGuy](#): > > Another approach is to use the fans to evacuate the airspace under the car and let the differential pressure vs. the ambient atmosphere stick the car to the road like a giant (but semi-leaky) suction cup. Yes, that’s what’s going on here. The builder specifically calls it a “reverse hovercraft”. If the road were perfectly smooth, a car could create a perfect seal and get, say, 50 tons of downforce. With no net power usage for the fan, in principle. Of course, they’re nowhere close to that level of efficiency here, but even a few percent reduction in air pressure would result in \>1 ton of downforce. ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [December 18, 2022, 2:45am UTC](https://boards.straightdope.com/t/bonkers-hypercar-breaks-1-4-mile-record-at-7-97-seconds-car-will-be-street-legal-i-think/976609/28 "2022-12-18T02:45:58Z")
Wouldn’t pulling air across wings be more efficient than just trying to suck the car down to the road? I mean, instead of sucking air from under the car and letting the atmosphere push it down why not suck air over an upside-down wing that pushes down rather than provide lift? So have some reverse wings inside the air intake tunnels on the car. As air moves over them it pushes the car down. Just guessing/asking here. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [December 18, 2022, 2:50am UTC](https://boards.straightdope.com/t/bonkers-hypercar-breaks-1-4-mile-record-at-7-97-seconds-car-will-be-street-legal-i-think/976609/29 "2022-12-18T02:50:31Z")
The problem with wings is the drag at the square of the lift thing. You certainly can do winged cars; Jim Hall at Chapparal once again was the pioneer here. But I don’t think you’re going to beat the basic 14.7psi of available downforce if only you could extract that air from under the car. ---
**Author:** ![mixdenny](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mixdenny/32/2962_2.png) [@mixdenny](https://boards.straightdope.com/u/mixdenny)\ **Post date:** [December 18, 2022, 3:31am UTC](https://boards.straightdope.com/t/bonkers-hypercar-breaks-1-4-mile-record-at-7-97-seconds-car-will-be-street-legal-i-think/976609/30 "2022-12-18T03:31:12Z")
> [@Chronos](#): > > Actually, come to think of it, for it to make sense to use the fan for downlift instead of for thrust, you’d need tires with a coefficient of friction greater than 1 (as well as a powerful engine turning those tires, of course). While this is possible, it requires special rubber that usually has a very low durability. Race cars routinely exceed 1 G when cornering. Top fuel dragsters exceed 5 Gs acceleration. Tires are pliable enough to push into the crevices in the road. So it is not two flat surfaces pressing against each other. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [December 19, 2022, 11:24am UTC](https://boards.straightdope.com/t/bonkers-hypercar-breaks-1-4-mile-record-at-7-97-seconds-car-will-be-street-legal-i-think/976609/31 "2022-12-19T11:24:40Z")
A more affordable version of the OP’s car: [![](https://img.youtube.com/vi/A6DYvFOQ7t0/maxresdefault.jpg "Drives on Walls! Remote Control Wall Climbing Car with Working Lights") ](https://www.youtube.com/watch?v=A6DYvFOQ7t0) [Previous page](https://boards.straightdope.com/t/bonkers-hypercar-breaks-1-4-mile-record-at-7-97-seconds-car-will-be-street-legal-i-think/976609.md?page=1)