Hey, im asking help from some of you drag racing gurus. Im doin a reprt for school and i need to know the different forces applied in drag racing..its for science and i figured i would see if i could get some help. Thanks Jimmy
any type of force involved in the race, friction, kenetic, potental energy, stuff like that and how its involved with the car goin down the track.
#2, high school or college level? #3, is this a homework assignment that you should be really thinking about these yourself instead of asking others to help you?
Aw give the kid a brake (sic). G forces are applied to anyone in the drivers seat. On the big end the g forces try to drag you off the end of the track while your brakes are using friction to slow you down. Friction is involved in getting traction while at the same time friction from your front tires is trying to keep you from getting traction. You use rotational ( torsional??) to get you moveing. We could probably do this all day but this should get your juices flowing. Chemistry or physics????? its a little late in the semester to be doing this isn't it. I mean hell my finals are next week. Oh an by the way most of this is probably absolutely wrong but so corn haired muther will try and make me look like an idiot and that should get you all the info you need to do your report.
There is a book was out in the 80's 90's called Auto Math,,you can find it all in there,,gear ratios,,force ,HP,BHP , got a copy somewhere will see if I can find you the author
When I was in high school physics class in 1968 we did an experiment where we tied a 1" wide paper tape to the back of a car and pulled it thru a device that had a vibrating marker on it going up and down at a fixed rate. The cars accelerated from a standing start (IE drag race style) and we could determine the acceleration from the spacing of the markings on the tape. A stock volkswagen beetle won, beat an SS 396 Chevelle that just spun the tires. This was for only the first 20 feet or so. Had a neat teacher that let us do things like this.
Weight Drag Downforce/Lift (lets hope you have more downforce than lift) Torque due to engine Horsepower (this is Work/time, specifically 1 horsepower = 550 ft lb/s) Center of Gravity (this gives you weight distribution between front and rear tires) You'll need to find the coefficient of friction of tires on pavement for transfer of force from engine to pavement Drive ratio (to determine forces at wheels) drive ratio includes both gear ratio and wheel size. There are plenty more if you look at even closer detail.
Something I learned while racing is that the negative G's generated by opening both parachutes at the same time for guys going really fast is enough to detach the retinas in your eyeballs!!!!!
thanks a lot guys...i got some ideas about what i wanna write on my paper and all...ya im goin to do it myself..most of it anyway just needed a little help to start and dont even tell me any of you didnt everrrr cheat or copy papers and what not haha
It sounds like you're looking for some quick reference materials and also some personal experience info from HAMB'ers. Here's some quick reference material links, not all drag racing but the physics are similar. It should get you pointed in the right direction: http://comp.uark.edu/~jjrencis/fsae/resources/physics-of-racing.pdf http://www.123helpme.com/view.asp?id=33548 http://www.hotrod.com/techarticles/chassis/chassis_tuning_tire_traction/index.html http://kgm.tiwing.com/articles/por/por_p01.htm The last link is pretty neat as it is the first in a 26 part series of articles regarding physics involved in racing. Some pretty good stuff to get you started anyway.
If you believe everything you read in a physics book, you will come to the conclusion that the maximum speed attainable in the quarter mile is about 165 mph. Turns out that prediction was empircally overturned in the '50s. An interesting force analysis is the fact that a modern drag car might launch at over 4 longitudinal g's. That means the tractive force applied by the tires is four times the weight of the car. This, in turn, means that the coefficient of friction for a modern drag tire is substantially in excess of one. Not what you would expect from reading your physics text, but observable almost any Sunday on TV.
One Top Fuel dragster 500 cubic inch Hemi engine makes more horsepower than the first 6 rows at the Daytona 500. Under full throttle, a dragster engine consumes 1 gallon of nitromethane per second; a fully loaded 747 consumes jet fuel at the same rate with 25% less energy being produced. A stock Dodge Hemi V8 engine cannot produce enough power to drive the dragster supercharger. It takes 1500+hp just to turn a top fuel blower. With 3000 CFM of air being rammed in by the supercharger on overdrive, the fuel mixture is compressed into a near- solid form before ignition. Cylinders run on the verge of hydraulic lock at full throttle. At the stoichiometric 1.7:1 air/ fuel mixture for nitromethane the flame front temperature measures 7050 degrees F. Nitromethane burns yellow. The spectacular white flame seen above the stacks at night is raw burning hydrogen, dissociated from atmospheric water vapor by the searing exhaust gases. Dual magnetos supply 44 amps to each spark plug. This is the output of an arc welder in each cylinder. Spark plug electrodes are totally consumed during a run. After ½ way, the engine is dieseling from compression plus the glow of exhaust valves at 1400 degrees F. The engine can only be shut down by cutting the fuel flow. If spark momentarily fails early in the run, unburned nitro builds up in the affected cylinders and then explodes with sufficient force to blow cylinder heads off the block in pieces or split the block in half. In order to exceed 300 mph in 4.5 seconds dragsters must accelerate at an average of over 4G's. In order to reach 200 mph well before half-track, the launch acceleration approaches 8Gs. Dragsters reach over 300 miles per hour before you have completed reading this sentence. Top Fuel Engines turn approximately 540 revolutions from light to light! Including the burnout, the engine must only survive 900 revolutions under load. The redline is actually quite high at 9500rpm. The pressure coming out of the headers can provide 1000lbs of downforce. When a cylinder goes out, it can actually steer the car due to loss of downforce on one side. There is so much torsional twist in the crankshaft (up to 20 degrees at the big end of the track) that sometimes cam lobes are ground offset from front to rear to try and re-phase the valve timing closer to synchronization with the pistons. The car will be going over 60mph before the rear wheels cross the start line, 300 inches. The Bottom Line; Assuming all the equipment is paid off, the crew worked for free, and for once NOTHING BLOWS UP, each run costs an estimated US$1,000.00 per second. The current Top Fuel dragster elapsed time record is 4.441 seconds for the quarter mile (10/05/03, Tony Schumacher). The top speed record is 333.00 mph (533 km/h) as measured over the last 66' of the run (09/28/03 Doug Kalitta). Putting all of this into perspective: You are driving the average $140,000 Lingenfelter "twin-turbo" powered Corvette Z06 (or blown Viper). Over a mile up the road, a Top Fuel dragster is staged and ready to launch down a quarter mile strip as you pass. You have the advantage of a flying start. You run the 'Vette hard up through the gears and blast across the starting line and past the dragster at an honest 200 mph. The 'tree' goes green for both of you at that moment. The dragster launches and starts after you. You keep your foot down hard, but you hear an incredibly brutal whine that sears your eardrums and within 3 seconds the dragster catches and passes you. He beats you to the finish line, a quarter mile away from where you just passed him. Think about it, from a standing start, the dragster had spotted you 200 mph and not only caught, but nearly blasted you off the road when he passed you within a mere 1320 foot long race course. Of course, you need to bear in mind that you are receiving all of this information from a guy who owns a Volkswagen that makes just enough power to blend a margarita.
If you believe everything you read in a physics book, you will come to the conclusion that the maximum speed attainable in the quarter mile is about 165 mph. And what "physics book" is that in?
It all comes down to Newton's three laws of motion......Google Isaac Newton and study, then apply what you have learned to drag racing. Do research, online, library, magazines etc. I would start with a project idea. How Newton's laws effect a drag car. Next I would form a hypothesis. The faster a car goes, resistance increases. Do an experiment. Use a leaf blower on a rheostat to move an arm attached to a pivot to show resistance at various speeds. Document the experiment with video cameras, edit and put results on a computer presentation. Collect data Show results in graph form. Find a mentor to help with suggestions Write a bibliography.
panic: And what "physics book" is that in? Turns out it was in I taught from a few years ago, and in several others. The key point of contention is that surface area has no bearing on the friction force, only the materials involved and the normal force. Following that reasoning, it isn't a difficult calculation to figure out how fast a race car will be going based on a maximum of 1 g acceleration. This information was famously published in the enthusiast press in the '50s, but it turns out the analysis is flawed. A modern dragster tire hooks to the ground more like an engaged gear than the friction from two smooth surfaces. Hence, the availability of up to 5 g's acceleration.
I think the whole physics being wrong debate in regards to drag racing is because mathematical models used to determine the maximum performance levels didn't take into account all of the variables involved. It was assumed that a complete physical connection would be made from the end of the crank to the pavement. Modern clutch managment systems controls excessive horsepower until it can effectively be used. While the motor is at max hp from start to finish, it is the clutch that prevents the tires from slippage. (hopefully) The other thing is what effect modern drag race tires has. Being allowed to "grow" makes the rear end ratio variable. Progressively lowering (numerically) the ratio. It wasn't that physics was wrong, it's just that not all of the variables were known at the time.
You are correct in saying that physics isn't wrong, but rather the model is flawed. The tractive connection between the tire and the pavement is clearly a different process than the friction of a book sitting on the table. That is the disconnect, and it has been well known for a few decades, although it wasn't always.
F = MA Resolve Force = Torque M = Weight of vehicle divided by gravity (force) A = Acceleration Physics Book has several simple formulas, and the JEGS or SUMMIT racing log books have some of the useful formulas as well. Software programas are available for your lap top as well, then you can input your know variables. You can then Take your desired ET in a Qtr with known mass, and then determine the torque you will need to reach your design goal....... Then add a blower to increase the volumetric efficiency of the engine > 100% and you may locate the $$$$ variable that is not in the above equations............... Have Fun..............
When I was college ten+ years ago, I wrote a paper for an Aerodynamics class (taught by the brilliant Dr. Peter Lissaman) on calculating drag on Top Fuel and Funny Car bodies...Unfortunately I no longer know where that paper is, but for what it's worth when I had some difficult questions, I called Hot Rod magazine, explained what I was doing and the editor at the time gave me Jon Asher's cell number...and then when I talked to Jon he gave me a few key phone numbers of people who built fuel cars and they were a wealth of information. Amazingly, every single person I talked to was supremely helpful-everyone helped little ol' me with my paper and I was really impressed with all the kindness I was shown. You're doing the right thing by asking here, but don't be afraid to also get on the horn and ask the folks that build and race the cars today. Best of luck with your report!
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