@@dodenmanniskan8846fighter pilots take vertical Gs mostly which are much easier for humans to take compared to lateral gs. Still super impressive but nothing compared to these forces
Exactly. They forgot about it. The exhaust pipe exit angle was actually reduced years ago, from the preferred 90deg. Was done to reduce downforce and thus speed due to safety reasons.
@@PozzaPizz Not when you realizes that you are burning about 2 gallons of fuel every second. At about 1.14 kg per liter, that means that you put out about 8 kg of exhaust every second. So to get to 1100lbs or 4900N of downforce, we just plug it in to our simplified trust equation to get the exhaust speed F = mv v=F/m 4900/8=612.5 m/s. So about mach 2 Can that be correct? The exhausts seem to be about 2 inches in diameter, one for each cylinder, this means that the total area is about pi*8*2.5^2 = 157 cm^2 = 0.0157 m^2. So with our flowrate of 612.5 m/s, that would mean we put out 0.0157*612.5 m/s = 9.6 m^3 of exhaust gasses every second. How much exhaust gas does 8kg of nitromethane produce when burned? Well that's a complicated question that depends on lots of factors like how clean the combustion is and how rich it is, but I think 9.6 m^3 is not a very high number seeing how you would require about 14kg of air to completely burn that nitromethane and that alone has a volume of about 18 m^3. ofc the combustion is FAR from complete in a dragster so us sitting at half that seems about right.
@@drunkenhobo8020 haha hehe tell that to the rocket they recently launched and then the first stage came back to earth just outside (or inside, couldn't tell) some rural village in China. I'm sure there will be no health effects for those people. The explosion was good sized, still had a ton of propellant
You'll make more power running on a mix of hydrazine and nitromethane than the regular nitro and methanol blend, but it is dangerous as hell since it's time sensitive and will spontaneously explode if you leave it for like 40min...
Some of the military aircraft I’ve worked on had hydrazine for the emergency start system (think engine dies in flight and needs a restart). They had indicators on the side of the jet that changed color when exposed to it. If you ever were to see that indicator change color you better start running.
Dragsters are rear wheel drive, but also designed so under full acceleration, the front tires are barely even touching the ground. So 95% of the weight is on the driven wheels already during a run.
@user-tz4lr8xe4d it wouldn't do a thing, the cars are 30 feet long they have all the leverage they can get, they are lifting the front tires and using wheeliebars now.. You have no idea what you are talking about with ground effects. And fans.
@@Idiomatick Do you have any concept of how bad awd vehicles react to drag racing? Should go watch fl2k and tx2k coverage when the skylines and stuff run. There is a good reason the fastest drag cars are not awd. Stop thinking uncontrollable 800hp skubadoos and think 10k hp top fuel cars... Aint gonna happen.
@@Idiomatick It would literally be unreliable and very very dangerous so stop thinking awd is fastest cause it's not it's also drivetrain loss and weight you do not need... Keep trying.
The change to exotic materials does lower mass but it also dramatically changes the dynamics of the entire car, and when it comes to Top Fuel dragsters the mass of the frame and the very tuned way it flexes is specifically part of the process of getting the tires to grip the track. I think you would have to lengthen the chassis to get some of that back. And the tires struggle mightily to hold the 11000 hp now, doubt they can hold twice the power.
@@Scoots1994 Nonsense. The drivers poo literally comes back out their bodies through their mouths and fills up in the crash helmet. I've seen it before in '78 when we changed the rubber compound.
I saw Sammy Miller when he took the record at Santa pod, I was 11. I've spent the last 41 years as a Toolmaker and development engineer because of people like Sammy Miller & Angus McPhail on Jade Warrior. As I understand it, the conrods in nitro burning engines are forged aluminium alloy. The reason being that the percussive force of the nitro exploding can shatter steel or titanium. Another piece of nerdery is that the rod length shortens after each run as the rods compress under the force.
Nitro cars use aluminum rods and actually shorten during a run from the high cylinder pressures. They act somewhat as a shock absorber compared to steel or Ti rods.
They rotate thru 6 to 8 sets of rods per weekend, they measure the rods to keep the lengths equal from the shortening to make set's and match pistons to them. the rods and pistons all bend down, so they measure the rods and the piston depths and match them up as best they can and adjust the compression ratios with them, the newer and longer the rod and taller the piston the higher the compression, then they adjust the compression ratio with the copper headgaskets to make even consistent power thru the life of the parts. I suggest watching Clay Millikans ytube channel on how nitro cars actually work.
@@Scootermagoo Ye nitromethane is a weird beastie. The main thing was I just thought they rebuilt maybe 4 or 5 times in a day (and maybe have 1 or 2 spare motors depending on the team's budget/class) Might check it out sometime- though I'm really more into open wheelers and tuner cars.
@@fredrikholmgren5287 He's right. They never shift gears. The gearing is done with the rear tire diameter growth from the beginning until top speed. And the clutch and its adjustment are key to making a good run
@@AzathothsAlarmClock No actually they have a clutch, the output goes into a reverser and then a output shaft to the rearend. They do not have a transmission and haven't used a gear change in close to 30 years now.
"0-60 acceleration tests have been the go-to statistic for drivers all over the world" Correction: "0-60 acceleration tests have been the go-to statistic for drivers in about 5% of the world"
The biggest reason exotic, lightweight materials are not used in Top Fuel or Funny Car racing classes is the fact that those engines produce anywhere from 11000 to 18000 horsepower, and lord knows what the torque output is. That much power would rip apart carbon fiber like so much wet paper. The chassis would explode on the starting line well before 10% of the maximum power is produced. The mandated chrome-molybdenum steel tubing chassis is strong enough and flexible enough to take the power that is output, but still requires frequent inspection of the welds in the chassis.
The ability of a material to withstand stress is dependent on the cross sectional area. So no lightweight exotic materials would not be torn apart by the power. they'd stand upto it just fine, (as they do in highstress applications like aircraft wings). But you couldn't just copy the tubular steel design 1 to 1. The reason top fuel doesn;t use them is to keep costs of the teams down.
Pretty sure top fuel dragsters in current form are running regularly under 4 seconds for quarter mile runs, so unless I misheard, I don't think your quote on the fastest top fuel quarter mile drag run of 4.4 seconds is correct. So, the theoretical speed you originally calculated of 3.8 seconds is actually spot on and quite common. Brittany Force has recorded a 3.665 run of 338mph as the fastest ever.
Currently Top Fuel dragsters do not compete full quarter mile, instead they do 1000 feet runs. Granted, with todays cars set up for quarter mile, they probably could shave a bit off from that 4,4 second time. But not much.
@@notmilandia8461 did some extremely basic math based off the fastest top fuel pass, 3.641 @ 338.48, if they kept rolling after 1000 to 1320 at 338, it would be a 4.28
Other than a few force/mass unit confusions, Driver61 certainly covered the bases if we restrict ourselves to a rubber tire-based force transfer concept. The only other thing to note is that the thrust force for a rubber tire is limited by the shear strength of the rubber itself. How about using a captive rack and pinion that runs the 1,320 feet? Steel has a lot higher shear strength than rubber. If we go completely "no rules" the limitation comes down to how much acceleration can a human stand. Does the human have to be able to control the vehicle? Does the human have to be in the vehicle? Col. John Stapp, strapped into a rocket sled in 1946 through 1951 survived up to 42.6 gs. Assuming that could be maintained over the ¼ mile the time would be 1.38 seconds crossing the line at just under 1,300 MPH. The human would not be capable of operating the vehicle during this, likely being unconscious, with broken bones, bleeding retinas etc. Col. Stapp was temporarily blinded by this; his friends have noted that he was changed by the experience. The fastest accelerating machine I am aware of short of an artillery shell is the Sprint short range AMB. Capable of 100 g acceleration. Lay it on its side (wheels or no), start it up and it will pass the ¼ mile point 0.9 seconds later passing 1,980 MPH, coming up on Mach 3. This assumes that aero drag would roughly cancel the decreasing mass as propellant was expended. I would not want to be in the stands, or within a mile. 20 if downrange, unless in a bunker.
I used to think Drag racing was too expensive for the amount of track/seat time but watching Cleetus Mc Farland videos has made me really respect it and how fast they can go in drag cars on good prep, but they don't do much of it in Ireland 🇮🇪
Fans need power. Power needs batteries, batteries add mass and take up space, increasing the aerodynamic cross-section. Besides, the downforce from the exhaust is considerable. (~1000 lb (450kg))
@@jackassplus Some of the additional 11 kHp of the main engine could possibly be used to drive the fans. I'm not sure that fans could provide the required ~20 kN of downforce consistently during the entire run though.
@@thebaddestogre-3698 yeah, and then fuse due to heat afterwards - motor lasts around 900 revolutions under load(burnout and run) until a full rebuild. They're wild machines, and video really does not convey the feeling of being next to an 11000hp nitro engine
@@SGIMartinIt really doesn't, I went to my first nitro event earlier this year and I've never experienced anything like it (even having stood next to fighter jets) totally unforgettable
@@mxtuner3351 I've seen rocket launches and fighter jets up close and honestly nothing comes close to top fuel, it just boggles your mind. You literally can't imagine what it's like to sit in the stands and feel those cars go past
i met sammy miller :) the driver of "vanishing point" rocket drag car. he was a real legend. all his records his car was tuned down. the car was powerful enough to go sub 3.2 sec in the 1/4 but would ET at 450-500mph - far too fast for any track. 3.58 record run was coasting from the 1/8th mile. he never fueled the car for the whole run. also if you want to up the top fuel rail - change the supercharger. get a twin screw or centrifugal. far more efficient which is why they are banned. only the roots type is permitted to strangle the engine to a mere 11,000 hp. also to note goodyear cant make a tyre that works over 350mph. thats one of the reasons why there is a limit and why top fuel only runs to 1000 feet (no longer 1/4 mile). we did recently have a new record where during an NHRA event Mike Salinas broke 300.80 mph in the 1/8th mile. incredible.
I've watched a video about top fuel dragsters some time ago and apparently their designers could easily increase the power, but then they couldn't put it down, so I don't think your estimations make sense. Probably removing most of the power part of the video would not make much difference in real time, so it would be more like 3.4s assuming the rest stays constant... which is slower than that alleged unofficial record of 3.22s. Still, I don't think these calculations can be taken seriously.
Hypergolic fuels in a piston engine?! That HAS to be right on top of the worst possible ideas in propulsion technology... Also, top fuel dragsters are running their tires at the very limit of their grip. If you doubled the power and halved the weight, where would you get the grip from to transfer said power it into the ground? Thinking about how grip works, there has to be a maximum balancing between grip to transfer the power and rolling resistance. The optimum for force transfer would be to concrete the tires to the ground. The optimum for rolling resistance would be tires covered in soap or oil or better yet, not even touching the ground. Increasing one necessarily takes the other away from it's optimum.
I'm old enough to remember when CalTech scientists declared "Given UNlimited horsepower & UNlimited traction, no dragster could ever go faster than 180 mph in the quarter mile." VERY shortly thereafter Tommy Ivo ("IF" I remember correctly / l'm old!) did it! 👍😮
You could do like some snow mobile racers, you pack the snow wet with a belt with the same cam distance as the snow mobile and let it freeze, then you have infinite grip and it's only the bending of cams or breaking the ice that matters.
As a motorcycle rider, i can tell you that rear wheel drive is only slower if your rear wheels don't have enough grip to lift the frontwheel of the ground
By the way there is different types of compounds used for drag racing tires as well as different prep for the strip itself so if you're on a big tire car you're going to be running less track prep so the tires can actually slip whereas with small Tire cars they're going to be running more track prep because you don't want the small Tire cars that initial slip
I doubt the effect of AWD at maximum acceleration. It is like the opposite of braking with a bicycle. If I brake hard enough and have the grip needed, my weight shifts completely to the front wheel and I can lift the rear wheel. This is how I get the shortest stopping distance. With accelerating a dragster it is the opposite. Acceleration transfers the weight back and the front wheels don't have anymore grip.
Of course there is weight transfer to the rear, but there is still weight on the front so those tires can still do work, not just not as much as the rears. Especially if your car is designed to maximize the AWD and weight is biased accordingly.
Saw legend 'Slammin' Sammy Miller do the Quarter mile 386mph run. Excelleration was clocked at 12G. 0-100mph in 0.36 seconds. First thing if watching 2/3rds along the track on launch you see the white shock wave . Then could hear the car over the Tannoy system before the actual sound hits you. Also saw him, again at Santa Pod do a 3.00 second run but for some reason it wasn't classed as official. I asked him about the force on his body. He replied because he was moving seated in a forward line position it wasn't an issue as unlike an aircraft that turns the blood doesn't try to rush to your head or feet so don't need a G-suit.
I don't think we'll ever see the likes of Sammy Miller and his amazing car, Vanishing Point, any time soon. That thing was absolutely amazing, and it's performance was difficult to convey to anyone who never saw it.
Are we going to casually ignore the idea of cutting weight to an absolute bare minimum, then strapping on a load of fans which likely weigh as much as what you've just battled to remove? 🤔 Plus the insane levels of G the driver would be under likely require heavy pressure suits to be worn.
"Plus the insane levels of G the driver would be under likely require heavy pressure suits to be worn." What even is this statment? Pressure suits doesnt save you from Gforces. And G-suits doesnt weigh much but they only marginally spare you from y-axis geforces. (like pulling a loop in a plane)
Our announcer friend doesn't know what he's talking about, he's playing with a 20 year old playbook. First they do not race nitrocars past a 1000 feet. So he's already wrong on pretty much everything he said. Second off the engines can't make unlimited power they are near the edge of hydrolocking the engines as it is. They literally cannot get more fuel into the chamber. Second off the cars are heavy due to the rules. Not because he made them up. The NHRA and the insurance companies have been slowing nitro cars down since the 60's. The 3.20 rear gear is used to limit top speeds under 350mph, the tires themselves will come apart if they go much faster. The engines have 8800rpm limiters on them, granted nitro doesn't care it'll run without a distributor as some race teams have learned. We wont talk about removing the second and at one point third magneto from the engine to limit power or the blower restrictions or... I wont even get into the problem with turbo chargers and the power they would add to the equation. it's not even close to possibly knowing the limit of the engine itself due to just the restrictive rules the tuners have to face, imagine the power 2 140mm turbos could add to this alone removing the blower as the actual restriction. Our man here doesn't know for which end his ass is speaking in this case.
Why do you need a driver. Could a robot not drive a vehicle in a straight line for 2.7 sek? Or maybe the aerodynamics of the car could keep is straight. What about a hydrogen power car? Low mass high energy density (at high pressure) it could also cool the engine
G suits work by constricting your lower body at high Gs, forcing your blood to stay in your brain. A fighter pilot experiences G forces vertically, so that's why the blood leaves the brain and accumulates in the lower body. In a race car/dragster they experience G forces horizontally (when they turn) and straight on (when they accelerate) but rarely vertically (only when they go up or down, like in Eau Rouge), so the G suit would not be very useful, they don't have to deal with blood leaving their brain, losing eyesight, going unconscious, etc, unlike fighter pilots. And they pull higher Gs (up to 11), for a lot longer, while fighting in a life and death situation. On the other hand, horizontal Gs mean that taking a turn puts enormous strain on your neck.
Using exotic material, it is more likely to boots the power up to 3 gazillion horsepower. Using an exotic frame would reduce the weight by 150%. So with that much power and a negative weight it should be doable, right? Well let me tell you, we tested it out after doing a lot of calculations and the result was astonishing. The car arrived at the finish line right before it started. Truly awesome, don't you think?
Problem with top fuel dragsters, is the are heavily restricted configurations, so they cant even modify their cars to make them faster, such as better superchargers, or non hemi engines, or non v8 configurations
Yup. I doubt those pushrods are in there because they’re better than OHC. Tire geometry (and number😉) is fixed. I think the final drive ratio is too. Everyone is point out that AWD is kinda moot because it’s basically impossible to keep the front tires down. Now throw tires that are 2x wider and can balloon even more and put two drive axles in the back (along with the active ground effect fans) and things would get seriously crazy.
7:20 Well, usually the main recognized ones are three, deformation (what you call indentation), adhesion and tear. Here's an excerpt on tear from the book "The Racing & High-Performance Tire": "Tearing and Wear In addition to adhesive friction and deformation friction, rubber produces traction forces by means of tearing and wear. As deformation forces and sliding speeds go up, local stress can exceed the tensile strength of the rubber, especially at an increase in local stress near the point of a sharp irregularity. High local stress can deform the internal structure of the rubber past the point of elastic recovery. When polymer bonds and crosslinks are stressed to failure the material can't recover completely, and this can cause tearing. Tearing absorbs energy, resulting in additional friction forces in the contact surface. Wear is the ultimate result of tearing. When local stresses increase in strength past initial tearing or remain at high strength for a period of time, that tearing can result in separation of material. The tire debris, bits of rolled-up rubber, you see on a racetrack is the result of rubber being torn and abraded from the tire. When these pieces separate from the tire, especially a race tire, they can be hot enough to stick together, so clumps of rubber as large as a baseball can be found on a racetrack or stuck to a racecar. In a later chapter we'll look closer at worn tires and what they can tell us."
Could you imagine being on board the US military rocket sled that holds the land-based speed record for a vehicle, at Mach 8.5? It reached that speed in less than 3 miles.
@2:34 Top Fuel dragsters are 0-100mph in 0.8 seconds, not 0-60mph. They cover the first 60 feet in around 0.830 of a second and that is starting from a dead stop. I think that is where you got your numbers wrong.
As for creating more power...Last time I checked the rules regarding computers for controlling ignition timing and fuel injection restricted them to passive data gathering only. After each pass the data gathered is analyzed and tuning adjustments for ignition timing, fuel curves, clutch tuning, and chassis tuning were then made manually to add or subtract power, clutch bite, tire traction all based on what the crew chief felt the track surface and atmospheric conditions could tolerate. In some cases an 11K hp engine might be detuned to 9.5K for example if track conditions were resulting in "Blowing off the tires" on the launch or later when the clutch fully engages. But if they were allowed to use closed loop systems capable of monitering wheelspin, clutch slippage, chassis flex, fuel/air ratio, spark advance, exhaust temperature, etc... and making thousands of adjustments in nano seconds the way flight control computers do exactly that on planes like the F22 then I would be willing to bet it wouldnt take long before we'd see dragsters acheiving between 1 and 2 seconds quicker elapsed times. Which is the exact reason they do not allow these systems in Top Fuel drag racing. Currently these cars are already so quick that even an experienced driver can have a hard time reacting quickly enough in the event that something goes wrong. And things do go wrong.
1:43 That's not the current Spa tho. Traction only matters if you have driven wheels. Rocket or jet powered cars don't have to worry about that. Also no, concrete *does not* have better traction than tarmac. The grip of a drag strip is all in the prep.
another reason for concrete is at some point the cars can begin to rip the asphalt up out of the ground. with enough power and traction of course. but yes the prep makes a much larger difference. one of those things no prep guys run into
But any sort of jet propulsion also is much less efficient at turning engine-power to movement of the vehicle itself compared to wheels. Its why the significant force coming from the exhaust nozzles on dragsters is aimed skywards and used to force the wheels into the ground, rather than contributing to acceleration by facing backwards. The extra grip from pushing the wheels into the ground offer better performance than trying to just push the vehicle forwards faster.
If a Top Fuel Dragster makes 800 pounds of thrust at the exhaust tips then you can see how the 0-40mph down force is created. What they need is dynamic exhaust to change from down force to longitude and gain the speed on the back end.
14:28 formula without parameters defined is a bit annoying. I don't see HP in it, but it's clear that low drag helps. Ok, wait Ft/m is Force on drive tire / mass. Ft=Power/v ...
Build a road with both lower and upper surfaces, so the rear tyres are held bottom and top. As they expand they push outwards on the upper and lower surfaces, providing maximum traction. The wing for downforce is replaced by pushing the 2 rear axles apart. Ultimate traction... @Driver61
That McMurtry just raised the bar more than anything in the last decade or two, that fan system changes everything, handling is on a different level now
If we make it a 4wd then the chassis is gonna be havier. as well as the tires and the WHOLE aerodynamics because of bulkkier front. Not even speaking about the hybrid idea you talked about. Batteries weight a shit ton and would most likely not provide the power of an internal combustion engine
At that point they would use capacitors instead of batteries to deal with the power output. Capacitors are heavier than batteries but they don't need to last for 300+ miles, only 4 seconds. A 10 kWh capacitor package would weight about 50 lb and could deliver almost 5000 HP for 5 seconds.
Two things, one Top Fuel / Funnycar dragsters don't have transmissions they use a direct drive multi clutch pack which is setup to slip off the start in order to control power delivered to the rear wheels. 2nd less know is that the engines exhaust is pointed up and back for a season to push down adding traction and back for thrust forward the exhaust plays a bigger factor than most realize...
It would be great if you interviewed a US Top Fuel Crew Cheif , the sports governing body the NHRA has been consistently trying to slow the cars down to improve driver safety and reduce insurance costs,, such things as reducing the distance to 1000 ft, restricting rear gearing, limiting the % amount of Nitomethane, minimum weight,banning electronic traction aids, banning Hydrazine etc, etc. Yet the best crew chiefs are able to overcome restrictions and devise engineering solutions to over come these restrictions and in many cases far surpass the previous performance levels. It would be very interesting to find out what they could actually do without any restrictions in place or no consideration of driver safety and available braking distance. These guys may be seen as grass roots but they are equally as talented as any engineers in any other wheel driven motorsports. I’m ignoring unlimited LSR vehicles because they are not wheel driven and powered by jet and more commonly rocket thrust.
Something I remember from a Cleetus Mcfarland video where is friend Kevin was building one of his road legal drag cars was the work they did on the rear suspension. They changed trailing arm angles to make the vehicle squat under hard acceleration transferring more of the vehicle's weight to the rear wheels. That car (Mullet) has done a 6.8 quarter mile so far, and drives to the meetings.
The connecting rods in those top fuel motors can also be made out of aluminum typically the blocks the heads, and the connecting rods are all made out of aluminum to reduce weight. But there’s significant longevity loss. Most of the big cars in NHRA use aluminum connecting rods when you get down bracket racing motors we use H beam steel rods. This is because at the top end you can be on and off the throttle killing numbers and it puts a lot of stress on the connecting rods and the crankshaft, and aluminum rods just can’t do that for a long amounts of time like these bracket motors need too.
You'd have a hard time finding anyone to drive it. Most of the current Top Fuel drivers don't believe that they could safely or reliably finish a 1/4 mile run safely using the current cars. (some of which destroy themselves in 1000 feet.
I saw Vanishing Point and Natural High race back in the early 80's at Englishtown New Jersey. It was unbelievable how fast those two cars went compared to everything else in any class at the time. They couldn't go full throttle at that track due to the size of the track, but it was impressive.
I believe it may be possible to go much faster in a dragster if the rules allowed for the following: - Carbon monocoque crash cell - Low drag carbon body - Fan forced ground effects for downforce instead of using big wings - No restrictions on engine design - Supercharger could be an axial compressor design or a centrifugal supercharger. Turbos would also be allowed. - 4WD hybrid using electric motors in the front wheels powered by supercapacitors to aid in acceleration and traction in the first few hundred feet - Supercharger or turbos use electric motors to help drive them (along with the engine)
I have another idea. remember that man hole cover, sealing an underground explosion, that got blasted into space? how about putting wheels on it and call it a car?!
Sir, that would make the car a projectile, and the guy inside would turn into mulch. That could work in an rc category ngl, canon projectile on wheels basicly.
At some point, the limiting factor is going to be geometry. Because the center of mass *has* to be above the road surface, the max Gs that you can pull is limited to the angle between the rear wheels and the center of mass. Fans and aero can help somewhat, but with a powerful enough motor, adding weight can actual increase the possible acceleration. If the center of mass was 50 cm of the ground, 2.7s to go 400m would require the CoM to be almost 6 meters in front of the rear axle. For the motor, you're probably better off going with electric motors. 600kg going 400m (1/4 mile) over 2.7s would require average output of 10MW, which could be accomplished with about 15 of the Koenigsegg "Dark Matter" e-motor. (probably an easier task than getting an engine running on hydrazine). You'd need 30 MJ (8300 Wh) of energy storage, which could be done with 128 kg of Skeleton's "SuperBatteries". Another option for the motor is to go completely unconventional, and use flywheels. Their biggest disadvantage is that they make it hard to turn, but that can actually be a benefit for a drag car. Another benefit here is that dumping all that angular momentum can help push the front wheels into the ground.
Nhra actually has the nitro classes rather restricted to keep speeds down. They could gain a lot of power by unrestricting the blower and final drive alone.
Either steel is 5 times denser than carbon fibre or carbon is 5x stronger, per kg, than steel in these appplications, I think you meant the latter. I enjoy your videos, and the way you make these things more approachable for the masses and look forward to more of your content in the future, thank you for your time and effort put into them.
I didn't realize Top Fuel dragsters were lighter than a Mazda Miata - that's wild! 12g for a couple seconds is survivable, but you might have to steer by eye-tracking
It’d be cool if f1 tracks used the same sticky track prep stuff over the entire track to see what really can be done if the driver knows grip is never going to be a problem
The cars mass does not "move backwards" during acceleration (some fuel will slosh but that is it). Applied loads under tires can vary during acceleration but the literal mass distribution of the car does not change.
@3:05 just curious, do you have the data that it went 0-60 in 0.6s or are you calculating based on the final speed and time achieved? Top fuel dragsters do not accelerate at a constant speed! They are accelerating slower in the beginning and as they gain speed and aerodynamic down-force they accelerate more in the second half. So just by going from the final speed and the time achieved you cannot calculate the acceleration in the beginning from 0-60. You have to have the logged data (mph & run time) to get that value.
_Vanishing Point_ (of which there were several) was rocket powered, thus traction wasn't an issue. Still, dragsters hit nearly 340 mph in just over 3.5 seconds, in only 1,000 feet (~305 meters).
im calculating 26000hp, you may need a bit more power since it wont weigh in 600, also need to take into consideration the down force and 26000hp would be net horsepower, you are gonna need even more horse power to take on drag and tyre friction, but to reach such speeds in such short time, it would be better just to strap a solid fuel rocket engine. So you decrease in mass more and have lots of power and the engine can last as long as needed. My take on it.
You mentioning hydrazine, a common fuel for spacecraft, makes me think - what if you upped to other rocket fuels? Hydrazine's pretty low end as far as those are concerned and mostly used in spacecraft for things like its simplicity and reliability, while launch vehicles use other fuels. For example, what if you followed the lead of most rockets and used a liquid bipropellant? For example, you can pair the hydrazine with something like nitrogen tetroxide (there are more efficient fuels, but fuel mass is a small amount so saving it probably doesn't matter much if it comes at the cost of power). If you're really crazy even go back to the '60s era rocketry and go for propellant mixtures including stuff like diborane and chlorine trifluoride
Carowinds in NC used to have a roller-coaster that went 0-60 in 1.1 seconds. It was mind blowing how hard it accelerated. I wouldn't ever want to go quicker than that. Acceleration was linear and maxed out at 120mph in 2.2 seconds.
One slight correction, 1/4 mile isn't "old school". Everything except top fuel dragster and funny car still run the full 1/4 mile. And the only reason those two classes run just 1000ft is because it was deemed too expensive & in some cases not possible to extend the safety runoffs. So they found that space by shortening the race distance by 320ft.
how is the finish time measured? is it the front of the car or the back of the car? or the centre of mass? could you make the car elongate itself during the run to get to the finish faster?
Rocket engines have the highest hp (in thrust) per kg ratio, and building a fast accelerating car with a rocket engine that has fuel for just a 10 second run is sure to break all acceleration records! You wont even need high grip tyres to achieve the speed, but you need some way to keep the car planted to the road or it may fly off, either via powerful suction fans or another rocket engine pushing the entire car downwards. Rocket engines in missiles are well known to accelerate to supersonic speeds from a standstill, which is ridiculous amount of acceleration, and fighter jet ejection seats are known to eject the pilot at upto 20gs of acceleration. There is a reason even the ssc bloodhound which is attempting to break the land speed record is using a combination of fighter jet engines and a rocket engine (though I really dont know what happened to the entire project now as I am not updated on it) I think if we want to make a fast accelerating drag car, Rocketlab’s Rutherford engine might be a small rocket engine with powerful thrust, but I’m not sure about the thrust to hp conversion, it still should provide enough power to thrust the car like a missile through the quarter mile straights!
Possible yes. But no sanctioning body would allow the rules to be broken to achieve it. Also nice that Tractor Pulls were mentioned those are something else. Also didn't you cover drag racing in a past video?
You didn't take into consideration that top fuel and funny cars are limited to a 3.20 rear end gear ratio. That should have some effect on the acceleration.
You could vastly increase the power with an unorthodox engine. For example, the fuel pump on a Saturn V, first stage F1 engine, the rocket nasa used in the Moon missions, made 35,000 hp. It ran on kerosine and oxygen.
I love drag racing. I've been watching several youtube channels for many years that do it. However the dragsters are so unrelatable, so abstract to me. The land speed record vehicles, basically just a jet engine with a cabin bolted on, is also so unrelatable. The promods or the funny-cars are borderline at the limit for me. They look like "normal" cars atleast. The classes where the cars have to drive between tracks, go down the strip, then go to the next track on its own, are the coolest in my opinion. And progress is still being made in those classes, constantly going quicker and faster. And like you mentioned they are mostly using RWD, not AWD, so there's still plenty of room for improvement. Carbon fibre and billet is becoming more affordable to more people. As we see with the latest Bugatti, AI/simulation is now involved in taking away material from components (250g here, 130g there adds up) while being just as strong and safe. So it's a fun sport to follow. Unlike in F1 the drag-and-drive stuff you can run so many different engine setups and components too, so it's really fun to see what people come up with, rather than everybody being exactly the same.
It would be a bit difficult to get more nitro/alcohol mixture into the engine, currently, dragsters have almost liquid lock at TDC there is so much fuel being pumped into the cylinder.
If you drop a car out of a plane it will accelerate at 9.8 m/s2. If you drop a model 1 beetle at a height it will hit terminal velocity it will hit the ground at 470 km/h, but it’s maximum speed during the fall would be 580 km/h (160 m/s) according to simulations. It slows from the max because of increasing air density the closer to the ground it gets.
if you wanted the fastest quarter mile this is my proposition where i recon sub 1 sec is possible have the floor and ceiling as rotating roads, like treadmills and keep the traditional right angled triangle shape of a drag car, have wheels on the front and back of the car, pointing up, with motors helping the car go quicker, this way, when the car takes off it will wheelie and have two wheels on the floor and 4 on the ceiling although whats wrong with having like 20 wheels helping out. also have it in a flying start because not worrying about acceleration means the car can start slowly, like two miles ahead of the 1/4 mile so it can reach its top speed for the start of the 1/4 mile and then with all this and the treadmills i think a car could do a sub 1 second 1/4 mile.
At some point, the driver’s reaction time becomes a factor too. A couple tenths either way makes a difference. The pavement itself also becomes a limiting factor. In order to get perfect acceleration, you need a perfect surface to do it on.
Could put a cable and pully like an aircraft carriers launch system down the center of both lanes and instead of pulling the cars all it would do, it would allow you to pull down on the car near the rear. This would allow you to get the best grip on the tires and allow the car to move down the track with the "Pull down cable" moving with the car down the center of the lanes underneith the road surface with just a slit in the Lane where the cable comes up to attach to the car, like an aircraft carrier has down the center of some of the runways
I would think the human body will be the limitation before you get to the theoretical car limit. They’re already over 6 Gs at the rate of acceleration currently. I’m not sure where scientists place the limit but going 0-60 in .8 has got to be getting pretty close.
It's almost all about traction. I think electric dragsters may eventually be faster than ICE ones because traction control can keep all 4 wheels delivering maximum power at all times. Only problem is I don't think we have batteries that can discharge quickly enough, meaning there would be a lot of excess weight in the form of batteries. Maybe supercapacitators could be used
Great vid !! Doubling the average combustion pressure (to reach double the output) within the framework of the engine geometry as used now, is highly unlikely. The beefed up crank, cylinder wals, pistons and conrods wil not be able to fit inside the required 8litres. But I like your way of thinking 🙂. I think we need turbo's, more air in = more fuel = more oompf. How much G would that expose the driver too ?
@ 14.45 he mentioned the formula for predicting 1/4 times pits an 11k top fuel dragster at 3.8 but the fastest recorded was 4.48. That's simply not right. Unless I misunderstood? John Forces daughter Brittney Force ran a 3.641 @ 338.48 back in 2022. I'd say that formula is pretty amazing! Maybe I heard something wrong, regardless great video!
Definitely went way over the top on your estimate, explained by many comments before mine. I do feel like if budget wasn't a limit, 3.5second quarter mile may be possible, but idk about much below that
BMW 328i (2.0L turbocharged inline-4, pre-2016 model): 5.7 seconds BMW 330i (2.0L turbocharged 4-cylinder): around 5.6 seconds. BMW 330e (plug-in hybrid): around 5.6 seconds. BMW 330i xDrive (2024 model, AWD): 5.3 seconds BMW 330e xDrive (plug-in hybrid AWD): 5.5 seconds BMW 330d (3.0L turbocharged diesel inline-6, European markets): 5.0 seconds A crappy 320i at 7.1 seconds does not represent the standard 3-series in any way shape or form.
A 2.7 quarter mile time would mean that the driver has to pull at least 11g
Some random florida man would be able to pull it off
@@VaibhavBshet His fat will absorb most of the forces and brain damage wont be an issue.
@@egj1975 The brain is mostly made of fat, so this checks out.
@@재준이 it's a very few seconds, yup. Jet pilots takes a bit less than 10 Gs on longer amount of time
@@dodenmanniskan8846fighter pilots take vertical Gs mostly which are much easier for humans to take compared to lateral gs. Still super impressive but nothing compared to these forces
8:36 Actually, the top fuel dragsters get some downforce from their exhaust, which is significant off the line
Exactly. They forgot about it. The exhaust pipe exit angle was actually reduced years ago, from the preferred 90deg. Was done to reduce downforce and thus speed due to safety reasons.
Insane to think that exhaust cases provide 1100lbs+ of downforce
@@PozzaPizz Its a form of thrust, in similar vein redbull used their blown diffuser this way.
@@PozzaPizz Not when you realizes that you are burning about 2 gallons of fuel every second. At about 1.14 kg per liter, that means that you put out about 8 kg of exhaust every second. So to get to 1100lbs or 4900N of downforce, we just plug it in to our simplified trust equation to get the exhaust speed F = mv v=F/m 4900/8=612.5 m/s. So about mach 2
Can that be correct? The exhausts seem to be about 2 inches in diameter, one for each cylinder, this means that the total area is about pi*8*2.5^2 = 157 cm^2 = 0.0157 m^2. So with our flowrate of 612.5 m/s, that would mean we put out 0.0157*612.5 m/s = 9.6 m^3 of exhaust gasses every second. How much exhaust gas does 8kg of nitromethane produce when burned? Well that's a complicated question that depends on lots of factors like how clean the combustion is and how rich it is, but I think 9.6 m^3 is not a very high number seeing how you would require about 14kg of air to completely burn that nitromethane and that alone has a volume of about 18 m^3. ofc the combustion is FAR from complete in a dragster so us sitting at half that seems about right.
Today i learned why the exhaust points up on a dragster and comes out both sides. I always thought it was just cos it looks sick.
You want to fuel a car with Hydrazine?
Chemists that grew up after the 60s just had a stroke.
Some of the Chinese Long March rockets use UDMH and N2O4. So best not to be in the flight path of one of those...
@@drunkenhobo8020 haha hehe tell that to the rocket they recently launched and then the first stage came back to earth just outside (or inside, couldn't tell) some rural village in China.
I'm sure there will be no health effects for those people. The explosion was good sized, still had a ton of propellant
You'll make more power running on a mix of hydrazine and nitromethane than the regular nitro and methanol blend, but it is dangerous as hell since it's time sensitive and will spontaneously explode if you leave it for like 40min...
It's also incredibly toxic and carcinogenic.
Some of the military aircraft I’ve worked on had hydrazine for the emergency start system (think engine dies in flight and needs a restart). They had indicators on the side of the jet that changed color when exposed to it. If you ever were to see that indicator change color you better start running.
Hydrazine! - good golly. You could kill the entire grandstand in one pass.
let's add a second fuel pump for a nice safe oxidizer like RFNA while we're at it!
When you see green flames, it's hydrazine.
@@michaelbuckersthey start the sr 71 engines on trimethal borane and it is also green
If it even makes it to the line...
How's Project Inversion going? Is the ball still rolling on it?
Perhaps a scale model would be a good step up, through a collaboration with Project Air or Kevin Talbot for example?? Could be a fun video :)
yeah, I was wondering about exactly this. is it dead in the water or still in active development?
Been hoping for an update on Project Inversion. Honestly feels like the project may have been cancelled
@@ruroot8321 This is exactly what's worrying me
@@jamesdrummond7684 Yep. Exactly what got me worried and prompted the comment
The trick to using hydrazine as a fuel is the added weight of the space suit for the driver.
And the crew, audience and the residents downwind...
drivers are expendable as long as they survive the race. safety is second to human greatness
@@jedswift look man do you want to break the record or not?
Monopropellant dragster... sounds like straight out of Kerbal Space Program.
lmfao im a KSP player
Dragsters are rear wheel drive, but also designed so under full acceleration, the front tires are barely even touching the ground. So 95% of the weight is on the driven wheels already during a run.
@user-tz4lr8xe4d it wouldn't do a thing, the cars are 30 feet long they have all the leverage they can get, they are lifting the front tires and using wheeliebars now.. You have no idea what you are talking about with ground effects. And fans.
@@Scootermagoo You'd have more tire contact area with more tires tho...
@@Idiomatick Do you have any concept of how bad awd vehicles react to drag racing? Should go watch fl2k and tx2k coverage when the skylines and stuff run. There is a good reason the fastest drag cars are not awd. Stop thinking uncontrollable 800hp skubadoos and think 10k hp top fuel cars... Aint gonna happen.
@@Idiomatick It would literally be unreliable and very very dangerous so stop thinking awd is fastest cause it's not it's also drivetrain loss and weight you do not need... Keep trying.
@@Scootermagoo I don't think awd would be better due to the weight. But more tire on ground is more traction obviously.
The change to exotic materials does lower mass but it also dramatically changes the dynamics of the entire car, and when it comes to Top Fuel dragsters the mass of the frame and the very tuned way it flexes is specifically part of the process of getting the tires to grip the track. I think you would have to lengthen the chassis to get some of that back. And the tires struggle mightily to hold the 11000 hp now, doubt they can hold twice the power.
I am sure the tires will be FINE 🔥
And if you lengthen the chassis you have to offset increased torsion, torque, whatever. Which could mean you'd have to increase mass...
I don't think the driver can take it.
@@zeroinfinity5864 Sure they can. The force is all in one direction so they can do a lot to prepare for it. The key is the short duration.
@@Scoots1994 Nonsense. The drivers poo literally comes back out their bodies through their mouths and fills up in the crash helmet. I've seen it before in '78 when we changed the rubber compound.
I saw Sammy Miller when he took the record at Santa pod, I was 11.
I've spent the last 41 years as a Toolmaker and development engineer because of people like Sammy Miller & Angus McPhail on Jade Warrior.
As I understand it, the conrods in nitro burning engines are forged aluminium alloy. The reason being that the percussive force of the nitro exploding can shatter steel or titanium. Another piece of nerdery is that the rod length shortens after each run as the rods compress under the force.
I remember vanishing point too!
Nitro cars use aluminum rods and actually shorten during a run from the high cylinder pressures. They act somewhat as a shock absorber compared to steel or Ti rods.
I knew they rebuilt like, constantly.. but every single run!?
@@Gu1tarZer0 Yes rebuild every single run and they only have about an hour to do it between rounds.
Waiter, waiter! More rods please!
They rotate thru 6 to 8 sets of rods per weekend, they measure the rods to keep the lengths equal from the shortening to make set's and match pistons to them. the rods and pistons all bend down, so they measure the rods and the piston depths and match them up as best they can and adjust the compression ratios with them, the newer and longer the rod and taller the piston the higher the compression, then they adjust the compression ratio with the copper headgaskets to make even consistent power thru the life of the parts. I suggest watching Clay Millikans ytube channel on how nitro cars actually work.
@@Scootermagoo Ye nitromethane is a weird beastie.
The main thing was I just thought they rebuilt maybe 4 or 5 times in a day (and maybe have 1 or 2 spare motors depending on the team's budget/class)
Might check it out sometime- though I'm really more into open wheelers and tuner cars.
Top fuel dragster doesn't have a transmission, they use a centrifugal clutch, and direct drive and a the reverse gear is in the rear end.
hm, check reality
@@fredrikholmgren5287 He's right. They never shift gears. The gearing is done with the rear tire diameter growth from the beginning until top speed. And the clutch and its adjustment are key to making a good run
Who would be able to shift anyway? You’re literally strapped in a rocket like Wile Coyote. You’re just hoping it doesn’t explode like his always did.
@@AzathothsAlarmClock No actually they have a clutch, the output goes into a reverser and then a output shaft to the rearend. They do not have a transmission and haven't used a gear change in close to 30 years now.
@DapperHesher the change in direction of that rotational energy is the entire point of the differential
"0-60 acceleration tests have been the go-to statistic for drivers all over the world"
Correction: "0-60 acceleration tests have been the go-to statistic for drivers in about 5% of the world"
Probably just in the Antarctic, where it is too cold to use Metric :)
The only part that matters, yes.
0-62 * 🤓
average US citizen...@@bongwaterbojack
In the racing community, using imperial is actually very common. Most drivers would refer to their speeds in MPH even in metric using countries
The biggest reason exotic, lightweight materials are not used in Top Fuel or Funny Car racing classes is the fact that those engines produce anywhere from 11000 to 18000 horsepower, and lord knows what the torque output is. That much power would rip apart carbon fiber like so much wet paper. The chassis would explode on the starting line well before 10% of the maximum power is produced. The mandated chrome-molybdenum steel tubing chassis is strong enough and flexible enough to take the power that is output, but still requires frequent inspection of the welds in the chassis.
Uhhhh... torque is usually 7000 PLUS lb-ft which worries me
The ability of a material to withstand stress is dependent on the cross sectional area. So no lightweight exotic materials would not be torn apart by the power. they'd stand upto it just fine, (as they do in highstress applications like aircraft wings). But you couldn't just copy the tubular steel design 1 to 1.
The reason top fuel doesn;t use them is to keep costs of the teams down.
Pretty sure top fuel dragsters in current form are running regularly under 4 seconds for quarter mile runs, so unless I misheard, I don't think your quote on the fastest top fuel quarter mile drag run of 4.4 seconds is correct. So, the theoretical speed you originally calculated of 3.8 seconds is actually spot on and quite common. Brittany Force has recorded a 3.665 run of 338mph as the fastest ever.
NHRA runs 1000 feet not 1320
Not true. Current top fuel competion in the US was reduced to 1000 ft.
Currently Top Fuel dragsters do not compete full quarter mile, instead they do 1000 feet runs. Granted, with todays cars set up for quarter mile, they probably could shave a bit off from that 4,4 second time. But not much.
@@tiagocosta791 then I take it back. I wasn't aware of this.
@@notmilandia8461 did some extremely basic math based off the fastest top fuel pass, 3.641 @ 338.48, if they kept rolling after 1000 to 1320 at 338, it would be a 4.28
Other than a few force/mass unit confusions, Driver61 certainly covered the bases if we restrict ourselves to a rubber tire-based force transfer concept. The only other thing to note is that the thrust force for a rubber tire is limited by the shear strength of the rubber itself. How about using a captive rack and pinion that runs the 1,320 feet? Steel has a lot higher shear strength than rubber.
If we go completely "no rules" the limitation comes down to how much acceleration can a human stand. Does the human have to be able to control the vehicle? Does the human have to be in the vehicle?
Col. John Stapp, strapped into a rocket sled in 1946 through 1951 survived up to 42.6 gs. Assuming that could be maintained over the ¼ mile the time would be 1.38 seconds crossing the line at just under 1,300 MPH. The human would not be capable of operating the vehicle during this, likely being unconscious, with broken bones, bleeding retinas etc. Col. Stapp was temporarily blinded by this; his friends have noted that he was changed by the experience.
The fastest accelerating machine I am aware of short of an artillery shell is the Sprint short range AMB. Capable of 100 g acceleration. Lay it on its side (wheels or no), start it up and it will pass the ¼ mile point 0.9 seconds later passing 1,980 MPH, coming up on Mach 3. This assumes that aero drag would roughly cancel the decreasing mass as propellant was expended.
I would not want to be in the stands, or within a mile. 20 if downrange, unless in a bunker.
I used to think Drag racing was too expensive for the amount of track/seat time but watching Cleetus Mc Farland videos has made me really respect it and how fast they can go in drag cars on good prep, but they don't do much of it in Ireland 🇮🇪
Used to watch top fuel on tv with dad back in the 80's. Watching Cleetus has me excited again about drag racing. I so want to do it now.
11:30 that’s not possible cuz engine block is already aboutta blow, now u want it to become less protected. It’s going to explode/melt in 1 second
Another key factor consists on reducing drag. Specially, if fans are added, it may be possible to decrease the rear wing size, improving aerodynamics.
Fans need power. Power needs batteries, batteries add mass and take up space, increasing the aerodynamic cross-section. Besides, the downforce from the exhaust is considerable. (~1000 lb (450kg))
@@jackassplus Some of the additional 11 kHp of the main engine could possibly be used to drive the fans.
I'm not sure that fans could provide the required ~20 kN of downforce consistently during the entire run though.
When thinking about mass and weight realizing that the earth moves around at 67,000 miles PER HOUR (107,000km/h) is crazy, it could be real
Why not strap a large solid fuel rocket calculated to burn for 1.5 seconds on the chassis? It solves traction, power en weight at once.
Might as well put a behind it to increase force at that point.
Anyone who's played Kerbal Space Program has tried this exact thing. Adding wheels to an srb...
Result may vary
I believe current top fuel dragsters are traction limited about 2/3 of the run.
Yup, literally the clutches slip all the way past 200mph to limit the power getting through the tires.
@@thebaddestogre-3698 yeah, and then fuse due to heat afterwards - motor lasts around 900 revolutions under load(burnout and run) until a full rebuild. They're wild machines, and video really does not convey the feeling of being next to an 11000hp nitro engine
@@SGIMartinIt really doesn't, I went to my first nitro event earlier this year and I've never experienced anything like it (even having stood next to fighter jets) totally unforgettable
@@sgkingly8392 I remember my first NHRA top fuel event. It truly boggles the mind when you see it and feel it in person the first time
@@mxtuner3351 I've seen rocket launches and fighter jets up close and honestly nothing comes close to top fuel, it just boggles your mind. You literally can't imagine what it's like to sit in the stands and feel those cars go past
i met sammy miller :) the driver of "vanishing point" rocket drag car. he was a real legend. all his records his car was tuned down. the car was powerful enough to go sub 3.2 sec in the 1/4 but would ET at 450-500mph - far too fast for any track. 3.58 record run was coasting from the 1/8th mile. he never fueled the car for the whole run.
also if you want to up the top fuel rail - change the supercharger. get a twin screw or centrifugal. far more efficient which is why they are banned. only the roots type is permitted to strangle the engine to a mere 11,000 hp. also to note goodyear cant make a tyre that works over 350mph. thats one of the reasons why there is a limit and why top fuel only runs to 1000 feet (no longer 1/4 mile). we did recently have a new record where during an NHRA event Mike Salinas broke 300.80 mph in the 1/8th mile. incredible.
I've watched a video about top fuel dragsters some time ago and apparently their designers could easily increase the power, but then they couldn't put it down, so I don't think your estimations make sense. Probably removing most of the power part of the video would not make much difference in real time, so it would be more like 3.4s assuming the rest stays constant... which is slower than that alleged unofficial record of 3.22s. Still, I don't think these calculations can be taken seriously.
The 3.22 was for 1000 feet, not 1320. They quit racing 1/4 mile a number of years ago
Hypergolic fuels in a piston engine?! That HAS to be right on top of the worst possible ideas in propulsion technology... Also, top fuel dragsters are running their tires at the very limit of their grip. If you doubled the power and halved the weight, where would you get the grip from to transfer said power it into the ground? Thinking about how grip works, there has to be a maximum balancing between grip to transfer the power and rolling resistance. The optimum for force transfer would be to concrete the tires to the ground. The optimum for rolling resistance would be tires covered in soap or oil or better yet, not even touching the ground. Increasing one necessarily takes the other away from it's optimum.
I was half listening then did a full on double take and rewind cause I KNOW he didn't just say we were gonna fuel this thing with hydrazine.......
I mean, he LITERALLY said; _use fans to suck the car_ like the McMurtry, then turn them off to reduce rolling resistance
I'm old enough to remember when CalTech scientists declared "Given UNlimited horsepower & UNlimited traction, no dragster could ever go faster than 180 mph in the quarter mile." VERY shortly thereafter Tommy Ivo ("IF" I remember correctly / l'm old!) did it! 👍😮
You know you can just google facts before typing stuff on the internet
Imagine the fool that said they then seeing ohh let's just use tom bailey's street car as an example... Some people are just not that smart.
@@clintonherring yeah, but to google facts before writing every single comment is not worth it. Its just internet.
@@ik749 yep on the same page.
@@clintonherring full sentence?
You could do like some snow mobile racers, you pack the snow wet with a belt with the same cam distance as the snow mobile and let it freeze, then you have infinite grip and it's only the bending of cams or breaking the ice that matters.
As a motorcycle rider, i can tell you that rear wheel drive is only slower if your rear wheels don't have enough grip to lift the frontwheel of the ground
By the way there is different types of compounds used for drag racing tires as well as different prep for the strip itself so if you're on a big tire car you're going to be running less track prep so the tires can actually slip whereas with small Tire cars they're going to be running more track prep because you don't want the small Tire cars that initial slip
I doubt the effect of AWD at maximum acceleration. It is like the opposite of braking with a bicycle. If I brake hard enough and have the grip needed, my weight shifts completely to the front wheel and I can lift the rear wheel. This is how I get the shortest stopping distance. With accelerating a dragster it is the opposite. Acceleration transfers the weight back and the front wheels don't have anymore grip.
Of course there is weight transfer to the rear, but there is still weight on the front so those tires can still do work, not just not as much as the rears. Especially if your car is designed to maximize the AWD and weight is biased accordingly.
Saw legend 'Slammin' Sammy Miller do the Quarter mile 386mph run. Excelleration was clocked at 12G. 0-100mph in 0.36 seconds. First thing if watching 2/3rds along the track on launch you see the white shock wave . Then could hear the car over the Tannoy system before the actual sound hits you. Also saw him, again at Santa Pod do a 3.00 second run but for some reason it wasn't classed as official. I asked him about the force on his body. He replied because he was moving seated in a forward line position it wasn't an issue as unlike an aircraft that turns the blood doesn't try to rush to your head or feet so don't need a G-suit.
Exactly, lots of people in the comment section confused about that.
Not as fast as I can click the like button
Good one😂
I don't think we'll ever see the likes of Sammy Miller and his amazing car, Vanishing Point, any time soon. That thing was absolutely amazing, and it's performance was difficult to convey to anyone who never saw it.
Are we going to casually ignore the idea of cutting weight to an absolute bare minimum, then strapping on a load of fans which likely weigh as much as what you've just battled to remove? 🤔 Plus the insane levels of G the driver would be under likely require heavy pressure suits to be worn.
Same goes for the engine
"Plus the insane levels of G the driver would be under likely require heavy pressure suits to be worn." What even is this statment? Pressure suits doesnt save you from Gforces. And G-suits doesnt weigh much but they only marginally spare you from y-axis geforces. (like pulling a loop in a plane)
Our announcer friend doesn't know what he's talking about, he's playing with a 20 year old playbook. First they do not race nitrocars past a 1000 feet. So he's already wrong on pretty much everything he said. Second off the engines can't make unlimited power they are near the edge of hydrolocking the engines as it is. They literally cannot get more fuel into the chamber. Second off the cars are heavy due to the rules. Not because he made them up. The NHRA and the insurance companies have been slowing nitro cars down since the 60's. The 3.20 rear gear is used to limit top speeds under 350mph, the tires themselves will come apart if they go much faster. The engines have 8800rpm limiters on them, granted nitro doesn't care it'll run without a distributor as some race teams have learned. We wont talk about removing the second and at one point third magneto from the engine to limit power or the blower restrictions or... I wont even get into the problem with turbo chargers and the power they would add to the equation. it's not even close to possibly knowing the limit of the engine itself due to just the restrictive rules the tuners have to face, imagine the power 2 140mm turbos could add to this alone removing the blower as the actual restriction. Our man here doesn't know for which end his ass is speaking in this case.
Why do you need a driver. Could a robot not drive a vehicle in a straight line for 2.7 sek? Or maybe the aerodynamics of the car could keep is straight. What about a hydrogen power car? Low mass high energy density (at high pressure) it could also cool the engine
G suits work by constricting your lower body at high Gs, forcing your blood to stay in your brain. A fighter pilot experiences G forces vertically, so that's why the blood leaves the brain and accumulates in the lower body.
In a race car/dragster they experience G forces horizontally (when they turn) and straight on (when they accelerate) but rarely vertically (only when they go up or down, like in Eau Rouge), so the G suit would not be very useful, they don't have to deal with blood leaving their brain, losing eyesight, going unconscious, etc, unlike fighter pilots.
And they pull higher Gs (up to 11), for a lot longer, while fighting in a life and death situation. On the other hand, horizontal Gs mean that taking a turn puts enormous strain on your neck.
Using exotic material, it is more likely to boots the power up to 3 gazillion horsepower. Using an exotic frame would reduce the weight by 150%. So with that much power and a negative weight it should be doable, right?
Well let me tell you, we tested it out after doing a lot of calculations and the result was astonishing. The car arrived at the finish line right before it started. Truly awesome, don't you think?
Problem with top fuel dragsters, is the are heavily restricted configurations, so they cant even modify their cars to make them faster, such as better superchargers, or non hemi engines, or non v8 configurations
Yup. I doubt those pushrods are in there because they’re better than OHC. Tire geometry (and number😉) is fixed. I think the final drive ratio is too. Everyone is point out that AWD is kinda moot because it’s basically impossible to keep the front tires down. Now throw tires that are 2x wider and can balloon even more and put two drive axles in the back (along with the active ground effect fans) and things would get seriously crazy.
7:20 Well, usually the main recognized ones are three, deformation (what you call indentation), adhesion and tear. Here's an excerpt on tear from the book "The Racing & High-Performance Tire":
"Tearing and Wear
In addition to adhesive friction and deformation friction, rubber produces traction forces by means of tearing and wear. As deformation forces and sliding speeds go up, local stress can exceed the tensile strength of the rubber, especially at an increase in local stress near the point of a sharp irregularity. High local stress can deform the internal structure of the rubber past the point of elastic recovery. When polymer bonds and crosslinks are stressed to failure the material can't recover completely, and this can cause tearing. Tearing absorbs energy, resulting in additional friction forces in the contact surface.
Wear is the ultimate result of tearing. When local stresses increase in strength past initial tearing or remain at high strength for a period of time, that tearing can result in separation of material. The tire debris, bits of rolled-up rubber, you see on a racetrack is the result of rubber being torn and abraded from the tire. When these pieces separate from the tire, especially a race tire, they can be hot enough to stick together, so clumps of rubber as large as a baseball can be found on a racetrack or stuck to a racecar. In a later chapter we'll look closer at worn tires and what they can tell us."
Could you imagine being on board the US military rocket sled that holds the land-based speed record for a vehicle, at Mach 8.5? It reached that speed in less than 3 miles.
Also to put into context, at Mach 8.5, you're covering a mile in a little over half a second. So three miles doesn't seem quite so big.
@2:34
Top Fuel dragsters are 0-100mph in 0.8 seconds, not 0-60mph.
They cover the first 60 feet in around 0.830 of a second and that is starting from a dead stop.
I think that is where you got your numbers wrong.
What happened to the tunnel experiment?
As for creating more power...Last time I checked the rules regarding computers for controlling ignition timing and fuel injection restricted them to passive data gathering only. After each pass the data gathered is analyzed and tuning adjustments for ignition timing, fuel curves, clutch tuning, and chassis tuning were then made manually to add or subtract power, clutch bite, tire traction all based on what the crew chief felt the track surface and atmospheric conditions could tolerate. In some cases an 11K hp engine might be detuned to 9.5K for example if track conditions were resulting in "Blowing off the tires" on the launch or later when the clutch fully engages. But if they were allowed to use closed loop systems capable of monitering wheelspin, clutch slippage, chassis flex, fuel/air ratio, spark advance, exhaust temperature, etc... and making thousands of adjustments in nano seconds the way flight control computers do exactly that on planes like the F22 then I would be willing to bet it wouldnt take long before we'd see dragsters acheiving between 1 and 2 seconds quicker elapsed times. Which is the exact reason they do not allow these systems in Top Fuel drag racing. Currently these cars are already so quick that even an experienced driver can have a hard time reacting quickly enough in the event that something goes wrong. And things do go wrong.
1:43 That's not the current Spa tho.
Traction only matters if you have driven wheels. Rocket or jet powered cars don't have to worry about that. Also no, concrete *does not* have better traction than tarmac. The grip of a drag strip is all in the prep.
He didn't say concrete has better traction, he said it is more consistent.
Actually listen to what he says before commenting
another reason for concrete is at some point the cars can begin to rip the asphalt up out of the ground. with enough power and traction of course. but yes the prep makes a much larger difference. one of those things no prep guys run into
But any sort of jet propulsion also is much less efficient at turning engine-power to movement of the vehicle itself compared to wheels.
Its why the significant force coming from the exhaust nozzles on dragsters is aimed skywards and used to force the wheels into the ground, rather than contributing to acceleration by facing backwards.
The extra grip from pushing the wheels into the ground offer better performance than trying to just push the vehicle forwards faster.
If a Top Fuel Dragster makes 800 pounds of thrust at the exhaust tips then you can see how the 0-40mph down force is created. What they need is dynamic exhaust to change from down force to longitude and gain the speed on the back end.
you're aware we want more of your videos right?
14:28 formula without parameters defined is a bit annoying. I don't see HP in it, but it's clear that low drag helps. Ok, wait Ft/m is Force on drive tire / mass. Ft=Power/v ...
I eat tacos on Tuesdays
Build a road with both lower and upper surfaces, so the rear tyres are held bottom and top. As they expand they push outwards on the upper and lower surfaces, providing maximum traction. The wing for downforce is replaced by pushing the 2 rear axles apart. Ultimate traction... @Driver61
0:08 that very hard to believe a car can travel 0-647kph in 3.22 sec the force that fast would kill the driver
The driver was trained to handle high g-forces in order to handle fast accelerations
Surprisingly it’s only around 5 and a half gs which is no problem when compared to the 46g record.
@@din0da5h75 bro 0-647kph @3.22sec is more the 5G
Have you seen the manned rocket sled test? It’s possible if you are trained.
@@AUKUSRCIt’s 5.68Gs which is pretty much what they said.
That McMurtry just raised the bar more than anything in the last decade or two, that fan system changes everything, handling is on a different level now
If we make it a 4wd then the chassis is gonna be havier. as well as the tires and the WHOLE aerodynamics because of bulkkier front. Not even speaking about the hybrid idea you talked about. Batteries weight a shit ton and would most likely not provide the power of an internal combustion engine
At that point they would use capacitors instead of batteries to deal with the power output. Capacitors are heavier than batteries but they don't need to last for 300+ miles, only 4 seconds. A 10 kWh capacitor package would weight about 50 lb and could deliver almost 5000 HP for 5 seconds.
Two things, one Top Fuel / Funnycar dragsters don't have transmissions they use a direct drive multi clutch pack which is setup to slip off the start in order to control power delivered to the rear wheels.
2nd less know is that the engines exhaust is pointed up and back for a season to push down adding traction and back for thrust forward the exhaust plays a bigger factor than most realize...
I love how the team forgot to add the dodge demon 170 in the 0-60 under 2 seconds section
Prepped drag strip with ideal conditions so usually it’s not taking seriously. Also it was with rollout so
It would be great if you interviewed a US Top Fuel Crew Cheif , the sports governing body the NHRA has been consistently trying to slow the cars down to improve driver safety and reduce insurance costs,, such things as reducing the distance to 1000 ft, restricting rear gearing, limiting the % amount of Nitomethane, minimum weight,banning electronic traction aids, banning Hydrazine etc, etc. Yet the best crew chiefs are able to overcome restrictions and devise engineering solutions to over come these restrictions and in many cases far surpass the previous performance levels. It would be very interesting to find out what they could actually do without any restrictions in place or no consideration of driver safety and available braking distance. These guys may be seen as grass roots but they are equally as talented as any engineers in any other wheel driven motorsports. I’m ignoring unlimited LSR vehicles because they are not wheel driven and powered by jet and more commonly rocket thrust.
Unless car can spin the wheels at top speed, it is underpowered.
Christian von Koeningsegg
Something I remember from a Cleetus Mcfarland video where is friend Kevin was building one of his road legal drag cars was the work they did on the rear suspension. They changed trailing arm angles to make the vehicle squat under hard acceleration transferring more of the vehicle's weight to the rear wheels. That car (Mullet) has done a 6.8 quarter mile so far, and drives to the meetings.
The entire chassis is a giant ladder bar. The thing flexes and arcs in the middle under acceleration. They don't call them floppers for nothing.
i love how casually you just drop the knowledge bomb of 402 mph in 3.22s
Glad to see some of the science of drag racing as I just recently went to the Don Garlitts Drag Racing museum and drag race museum hall of fame
The connecting rods in those top fuel motors can also be made out of aluminum typically the blocks the heads, and the connecting rods are all made out of aluminum to reduce weight. But there’s significant longevity loss. Most of the big cars in NHRA use aluminum connecting rods when you get down bracket racing motors we use H beam steel rods. This is because at the top end you can be on and off the throttle killing numbers and it puts a lot of stress on the connecting rods and the crankshaft, and aluminum rods just can’t do that for a long amounts of time like these bracket motors need too.
I would love to watch someone build this machine. The amount of problems that need to be solve would be massive but ground breaking i imagine.
You'd have a hard time finding anyone to drive it. Most of the current Top Fuel drivers don't believe that they could safely or reliably finish a 1/4 mile run safely using the current cars. (some of which destroy themselves in 1000 feet.
You’d need Elon Musk to sponsor the project. It would be the most expensive race car in the history of mankind.
I saw Vanishing Point and Natural High race back in the early 80's at Englishtown New Jersey. It was unbelievable how fast those two cars went compared to everything else in any class at the time. They couldn't go full throttle at that track due to the size of the track, but it was impressive.
I believe it may be possible to go much faster in a dragster if the rules allowed for the following:
- Carbon monocoque crash cell
- Low drag carbon body
- Fan forced ground effects for downforce instead of using big wings
- No restrictions on engine design
- Supercharger could be an axial compressor design or a centrifugal supercharger. Turbos would also be allowed.
- 4WD hybrid using electric motors in the front wheels powered by supercapacitors to aid in acceleration and traction in the first few hundred feet
- Supercharger or turbos use electric motors to help drive them (along with the engine)
Another BRILLIANT video Scott! It is incredibly interesting how you pull all the variables together.
I have another idea. remember that man hole cover, sealing an underground explosion, that got blasted into space? how about putting wheels on it and call it a car?!
Sir, that would make the car a projectile, and the guy inside would turn into mulch. That could work in an rc category ngl, canon projectile on wheels basicly.
At some point, the limiting factor is going to be geometry. Because the center of mass *has* to be above the road surface, the max Gs that you can pull is limited to the angle between the rear wheels and the center of mass. Fans and aero can help somewhat, but with a powerful enough motor, adding weight can actual increase the possible acceleration. If the center of mass was 50 cm of the ground, 2.7s to go 400m would require the CoM to be almost 6 meters in front of the rear axle.
For the motor, you're probably better off going with electric motors. 600kg going 400m (1/4 mile) over 2.7s would require average output of 10MW, which could be accomplished with about 15 of the Koenigsegg "Dark Matter" e-motor. (probably an easier task than getting an engine running on hydrazine). You'd need 30 MJ (8300 Wh) of energy storage, which could be done with 128 kg of Skeleton's "SuperBatteries".
Another option for the motor is to go completely unconventional, and use flywheels. Their biggest disadvantage is that they make it hard to turn, but that can actually be a benefit for a drag car. Another benefit here is that dumping all that angular momentum can help push the front wheels into the ground.
Nhra actually has the nitro classes rather restricted to keep speeds down. They could gain a lot of power by unrestricting the blower and final drive alone.
1:06...But faster 0-60 is not a problem, it's a want to have just for the sake of it 😅
3:06 bro at this point even the Bugatti new car can't best that much
Either steel is 5 times denser than carbon fibre or carbon is 5x stronger, per kg, than steel in these appplications, I think you meant the latter. I enjoy your videos, and the way you make these things more approachable for the masses and look forward to more of your content in the future, thank you for your time and effort put into them.
12:50 The fuel pump is very powerful. Calibration factor: The fuel pump on a first stage motor of the Saturn V rocket produced 50 000hp!
I didn't realize Top Fuel dragsters were lighter than a Mazda Miata - that's wild!
12g for a couple seconds is survivable, but you might have to steer by eye-tracking
It’d be cool if f1 tracks used the same sticky track prep stuff over the entire track to see what really can be done if the driver knows grip is never going to be a problem
The cars mass does not "move backwards" during acceleration (some fuel will slosh but that is it). Applied loads under tires can vary during acceleration but the literal mass distribution of the car does not change.
@3:05 just curious, do you have the data that it went 0-60 in 0.6s or are you calculating based on the final speed and time achieved?
Top fuel dragsters do not accelerate at a constant speed! They are accelerating slower in the beginning and as they gain speed and aerodynamic down-force they accelerate more in the second half.
So just by going from the final speed and the time achieved you cannot calculate the acceleration in the beginning from 0-60. You have to have the logged data (mph & run time) to get that value.
tail
_Vanishing Point_ (of which there were several) was rocket powered, thus traction wasn't an issue.
Still, dragsters hit nearly 340 mph in just over 3.5 seconds, in only 1,000 feet (~305 meters).
I'm glad you did this because when I theorize about stuff people seem to have blinders on past what they can see in front of them right now
im calculating 26000hp, you may need a bit more power since it wont weigh in 600, also need to take into consideration the down force and 26000hp would be net horsepower, you are gonna need even more horse power to take on drag and tyre friction, but to reach such speeds in such short time, it would be better just to strap a solid fuel rocket engine. So you decrease in mass more and have lots of power and the engine can last as long as needed. My take on it.
You mentioning hydrazine, a common fuel for spacecraft, makes me think - what if you upped to other rocket fuels? Hydrazine's pretty low end as far as those are concerned and mostly used in spacecraft for things like its simplicity and reliability, while launch vehicles use other fuels. For example, what if you followed the lead of most rockets and used a liquid bipropellant? For example, you can pair the hydrazine with something like nitrogen tetroxide (there are more efficient fuels, but fuel mass is a small amount so saving it probably doesn't matter much if it comes at the cost of power). If you're really crazy even go back to the '60s era rocketry and go for propellant mixtures including stuff like diborane and chlorine trifluoride
Carowinds in NC used to have a roller-coaster that went 0-60 in 1.1 seconds. It was mind blowing how hard it accelerated. I wouldn't ever want to go quicker than that. Acceleration was linear and maxed out at 120mph in 2.2 seconds.
One slight correction, 1/4 mile isn't "old school". Everything except top fuel dragster and funny car still run the full 1/4 mile. And the only reason those two classes run just 1000ft is because it was deemed too expensive & in some cases not possible to extend the safety runoffs. So they found that space by shortening the race distance by 320ft.
12:15 *PWRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR*
how is the finish time measured? is it the front of the car or the back of the car? or the centre of mass? could you make the car elongate itself during the run to get to the finish faster?
Rocket engines have the highest hp (in thrust) per kg ratio, and building a fast accelerating car with a rocket engine that has fuel for just a 10 second run is sure to break all acceleration records! You wont even need high grip tyres to achieve the speed, but you need some way to keep the car planted to the road or it may fly off, either via powerful suction fans or another rocket engine pushing the entire car downwards.
Rocket engines in missiles are well known to accelerate to supersonic speeds from a standstill, which is ridiculous amount of acceleration, and fighter jet ejection seats are known to eject the pilot at upto 20gs of acceleration. There is a reason even the ssc bloodhound which is attempting to break the land speed record is using a combination of fighter jet engines and a rocket engine (though I really dont know what happened to the entire project now as I am not updated on it)
I think if we want to make a fast accelerating drag car, Rocketlab’s Rutherford engine might be a small rocket engine with powerful thrust, but I’m not sure about the thrust to hp conversion, it still should provide enough power to thrust the car like a missile through the quarter mile straights!
Possible yes. But no sanctioning body would allow the rules to be broken to achieve it. Also nice that Tractor Pulls were mentioned those are something else. Also didn't you cover drag racing in a past video?
@12:59 Top Fuel piston connecting rods are made from 6061-T651 aluminum, not steel or titanium.
9:57 its the "weight" (force) that moves, the "mass" doesn't change as it's the matter, the stuff you can touch.
You didn't take into consideration that top fuel and funny cars are limited to a 3.20 rear end gear ratio. That should have some effect on the acceleration.
You could vastly increase the power with an unorthodox engine.
For example, the fuel pump on a Saturn V, first stage F1 engine, the rocket nasa used in the Moon missions, made 35,000 hp. It ran on kerosine and oxygen.
I love drag racing. I've been watching several youtube channels for many years that do it. However the dragsters are so unrelatable, so abstract to me. The land speed record vehicles, basically just a jet engine with a cabin bolted on, is also so unrelatable. The promods or the funny-cars are borderline at the limit for me. They look like "normal" cars atleast. The classes where the cars have to drive between tracks, go down the strip, then go to the next track on its own, are the coolest in my opinion. And progress is still being made in those classes, constantly going quicker and faster. And like you mentioned they are mostly using RWD, not AWD, so there's still plenty of room for improvement. Carbon fibre and billet is becoming more affordable to more people. As we see with the latest Bugatti, AI/simulation is now involved in taking away material from components (250g here, 130g there adds up) while being just as strong and safe. So it's a fun sport to follow. Unlike in F1 the drag-and-drive stuff you can run so many different engine setups and components too, so it's really fun to see what people come up with, rather than everybody being exactly the same.
It would be a bit difficult to get more nitro/alcohol mixture into the engine, currently, dragsters have almost liquid lock at TDC there is so much fuel being pumped into the cylinder.
If you drop a car out of a plane it will accelerate at 9.8 m/s2. If you drop a model 1 beetle at a height it will hit terminal velocity it will hit the ground at 470 km/h, but it’s maximum speed during the fall would be 580 km/h (160 m/s) according to simulations. It slows from the max because of increasing air density the closer to the ground it gets.
if you wanted the fastest quarter mile this is my proposition where i recon sub 1 sec is possible
have the floor and ceiling as rotating roads, like treadmills and keep the traditional right angled triangle shape of a drag car, have wheels on the front and back of the car, pointing up, with motors helping the car go quicker, this way, when the car takes off it will wheelie and have two wheels on the floor and 4 on the ceiling although whats wrong with having like 20 wheels helping out. also have it in a flying start because not worrying about acceleration means the car can start slowly, like two miles ahead of the 1/4 mile so it can reach its top speed for the start of the 1/4 mile and then with all this and the treadmills i think a car could do a sub 1 second 1/4 mile.
At some point, the driver’s reaction time becomes a factor too. A couple tenths either way makes a difference. The pavement itself also becomes a limiting factor. In order to get perfect acceleration, you need a perfect surface to do it on.
Could put a cable and pully like an aircraft carriers launch system down the center of both lanes and instead of pulling the cars all it would do, it would allow you to pull down on the car near the rear. This would allow you to get the best grip on the tires and allow the car to move down the track with the "Pull down cable" moving with the car down the center of the lanes underneith the road surface with just a slit in the Lane where the cable comes up to attach to the car, like an aircraft carrier has down the center of some of the runways
I would think the human body will be the limitation before you get to the theoretical car limit. They’re already over 6 Gs at the rate of acceleration currently. I’m not sure where scientists place the limit but going 0-60 in .8 has got to be getting pretty close.
At 10:59 I was so ready for him to say that steel is 5x heavier than feathers.
Slight correction. Nitro engines use aluminum connecting rods for shock absorption due to the violent combustion of nitro.
It's almost all about traction. I think electric dragsters may eventually be faster than ICE ones because traction control can keep all 4 wheels delivering maximum power at all times. Only problem is I don't think we have batteries that can discharge quickly enough, meaning there would be a lot of excess weight in the form of batteries. Maybe supercapacitators could be used
Great vid !! Doubling the average combustion pressure (to reach double the output) within the framework of the engine geometry as used now, is highly unlikely. The beefed up crank, cylinder wals, pistons and conrods wil not be able to fit inside the required 8litres. But I like your way of thinking 🙂. I think we need turbo's, more air in = more fuel = more oompf. How much G would that expose the driver too ?
@ 14.45 he mentioned the formula for predicting 1/4 times pits an 11k top fuel dragster at 3.8 but the fastest recorded was 4.48. That's simply not right. Unless I misunderstood? John Forces daughter Brittney Force ran a 3.641 @ 338.48 back in 2022. I'd say that formula is pretty amazing! Maybe I heard something wrong, regardless great video!
Definitely went way over the top on your estimate, explained by many comments before mine. I do feel like if budget wasn't a limit, 3.5second quarter mile may be possible, but idk about much below that
BMW 328i (2.0L turbocharged inline-4, pre-2016 model): 5.7 seconds
BMW 330i (2.0L turbocharged 4-cylinder): around 5.6 seconds.
BMW 330e (plug-in hybrid): around 5.6 seconds.
BMW 330i xDrive (2024 model, AWD): 5.3 seconds
BMW 330e xDrive (plug-in hybrid AWD): 5.5 seconds
BMW 330d (3.0L turbocharged diesel inline-6, European markets): 5.0 seconds
A crappy 320i at 7.1 seconds does not represent the standard 3-series in any way shape or form.