Author Topic: MOTO MATHS: We can work it out ...  (Read 14341 times)

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Offline Mike52

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Re: MOTO MATHS: We can work it out ...
« Reply #30 on: May 23, 2014, 08:21:45 am »
how many crankshaft revolutions does a Top Fuel dragster do in a 4.5 second run from green light to finish line (Only)  20000, 30000, 40000 50000+?

Not being smart Tim but at 8000 rpm = 599 revs and at 10000rpm 749revs. :o
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Offline GMC

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Re: MOTO MATHS: We can work it out ...
« Reply #31 on: May 23, 2014, 11:21:47 am »
No. ONE:
   In November, 1970, a Yamaha RT1 Enduro is cruising highway at 5,700 RPM, and sits on 95 kph.

Question:  How far does it travel (in metres) per single revolution of the crankshaft?

I came up with 3.6
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Offline Big John

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Re: MOTO MATHS: We can work it out ...
« Reply #32 on: May 23, 2014, 01:09:56 pm »
Double check your awnser Geoff.
 3.6 m/rev X 5700 RPM = 20520 m/min X 60 = 1231200 m/h divide by 1000 to get kph, 1231.2 kph
Even a well tuned rt1, down hill, wont get to those sorts of speed.

Offline GMC

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Re: MOTO MATHS: We can work it out ...
« Reply #33 on: May 23, 2014, 02:26:22 pm »
Doh!
I didn't think it all the way through
3.6 is the number of revolutions per metre so distance traveled per revolution is 0.27777 mtrs as already mentioned.

I have heard of DT owners making exorbitant claims about top speed though

I can calculate the dimensions for an expansion chamber though.
No, no, honest, I can
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Offline pancho

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Re: MOTO MATHS: We can work it out ...
« Reply #34 on: May 23, 2014, 04:18:10 pm »
Doh!
I didn't think it all the way through
3.6 is the number of revolutions per metre so distance traveled per revolution is 0.27777 mtrs as already mentioned.

I have heard of DT owners making exorbitant claims about top speed though

I can calculate the dimensions for an expansion chamber though.
No, no, honest, I can

Just need to ride a RT1 to know its twu.
dont follow me i'm probably off line!

Offline Tim754

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Re: MOTO MATHS: We can work it out ...
« Reply #35 on: May 23, 2014, 06:10:18 pm »
Not being smart Tim but at 8000 rpm = 599 revs and at 10000rpm 749revs. :o   OOPS I should have said  800 :-[ 
1800 allows for the unavoidable wheelspin from the slicks from the 1000+hp per cylinder bit.
 Still I would be amazed at how many answer 50000+ ;)
 Read the bit about ANDRA being the only major competition around the world that still runs the full quarter mile ;)
« Last Edit: May 23, 2014, 07:44:54 pm by Tim754 »
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Offline Mike52

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Re: MOTO MATHS: We can work it out ...
« Reply #36 on: May 23, 2014, 07:01:20 pm »
Not being smart Tim but at 8000 rpm = 599 revs and at 10000rpm 749revs. :o   OOPS I should have said  800 :-[  1800 allows for the unavailable wheelspin from the slicks from the 1000+hp per cylinder bit.
 Still I would be amazed at how many answer 50000+ ;)
 Read the bit about ANDRA being the only major competition around the world that still runs the full quarter mile ;)
The first time i saw the revs per 1/4 mile i was stunned.
They were quoting about 480revs [ slow revver ] which sounds insane until you do the maths.
A better one was the fuel used in that 4.5 secs.
If I remember right it was over 100 ltrs.
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oldfart

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Re: MOTO MATHS: We can work it out ...
« Reply #37 on: May 23, 2014, 07:24:04 pm »
    Quote   "A ride of a life time "    Tim you will enjoy this  ;)
http://www.youtube.com/watch?v=03Ybyq6osNY&feature=youtu.be&a

Offline mustanggrahame

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Re: MOTO MATHS: We can work it out ...
« Reply #38 on: May 23, 2014, 08:19:34 pm »
I dont think 100litres is correct Mike. I have heard 20-22 for a single pass. Another interesting fact is that a top fuel engine's crankshaft can twist up to 25 degrees from front to back under full load. Camshafts are set to take this into account.
Cheers, Grahame
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Offline 80-85 husky

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Re: MOTO MATHS: We can work it out ...
« Reply #39 on: May 24, 2014, 08:58:12 am »
I read a stat that if a dragster was to stage as a moto gp bike went past at top speed, the draggy would still beat it to the 1/4 mile post..where the brains trust on working that out?

oldfart

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Re: MOTO MATHS: We can work it out ...
« Reply #40 on: May 24, 2014, 10:54:59 am »
pause and read consumption at 18 seconds
http://www.youtube.com/watch?v=bS9VTapHRHg
« Last Edit: May 24, 2014, 10:56:50 am by oldfart »

oldfart

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Re: MOTO MATHS: We can work it out ...
« Reply #41 on: May 24, 2014, 11:03:20 am »
Some real cool facts about top fuel dragsters I stumbled across.....

---------
* One dragster's 500-inch Hemi makes more horsepower then the first 8 rows at Daytona.

* Under full throttle, a dragster engine consumes 1 1/2 gallons of nitro per second, the same rate of fuel consumption as a fully loaded 747 but with 4 times the energy volume.

* The supercharger takes more power to drive than a stock hemi makes.

* Even with nearly 3000 CFM of air being rammed in by the supercharger on overdrive, the fuel mixture is compressed into nearly-solid form before ignition. Cylinders run on the verge of hydraulic lock.

* Dual magnetos apply 44 amps to each spark plug. This is the output of an arc welder in each cylinder.

* At stoichiometric (exact) 1.7:1 air/fuel mixture (for nitro), the flame front of nitromethane 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.

* Spark plug electrodes are totally consumed during a pass. After 1/2 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 off its fuel flow.

* If spark momentarily fails early in the run, unburned nitro builds up in those cylinders and then explodes with a force that can blow cylinder heads off the block in pieces or blow the block in half.

* Dragsters twist the crank (torsionally) so far (20 degrees in the big end of the track) that sometimes cam lobes are ground offset from front to rear to re-phase the valve timing somewhere closer to synchronization with the pistons.

* To exceed 300mph in 4.5 seconds dragsters must accelerate at an average of over 4G's. But in reaching 200 mph well before 1/2 track, launch acceleration is closer to 8G's.

* If all the equipment is paid off, the crew worked for free, and for once NOTHING BLOWS UP, each run costs $1000.00 per second.

* Dragsters reach over 300 miles per hour before you have read this sentence.

Did you know …

… that the nitromethane-powered engines of NHRA Top Fuel dragsters and Funny Cars produce approximately 7,000 horsepower, about 37 times that of the average street car?

… that one cylinder of the eight cylinders of a Top Fuel dragster or a Funny Car produces 750 horsepower, equaling the entire horsepower output of a NASCAR engine?

… that the gasoline-powered engines of NHRA Pro Stock cars produce about 1,200 horsepower, about eight times that of the average street car?

… that an NHRA Top Fuel dragster accelerates from 0 to 100 mph in less than .8-second, almost 11 seconds quicker than it takes a production Porsche 911 Turbo to reach the same speed?

… that an NHRA Top Fuel dragster leaves the starting line with a force nearly five times that of gravity, the same force of the space shuttle when it leaves the launching pad at Cape Canaveral?

… that an NHRA Funny Car is slowed by a reverse force more than seven times that of gravity when both parachutes deploy simultaneously?

… that NHRA Top Fuel dragsters and Funny Cars consume between four and five gallons of fuel during a quarter-mile run, which is equivalent to between 16 and 20 gallons per mile?

… that NHRA Top Fuel dragsters and Funny Cars use between 10 and 12 gallons of fuel for a complete pass, including the burnout, backup to the starting line, and quarter-mile run?

… that NHRA Top Fuel dragsters and Funny Cars travel the length of more than four football fields in less than five seconds?

… that NHRA Top Fuel dragsters can exceed 280 mph in just 660 feet?

… that from a standing start, NHRA Top Fuel dragsters accelerate faster than a jumbo jet, a fighter jet, and a Formula One race car?

… that a fuel pump for an NHRA Top Fuel dragster and Funny Car delivers 65 gallons of fuel per minute, equivalent to eight bathroom showers running at the same time?

… that the fuel-line pressure for NHRA Top Fuel dragsters and Funny Cars is between 400 and 500 pounds, about 20 times greater than the pressure on passenger-car fuel pumps?

… that depending on size and angle, the large rear wing on an NHRA Top Fuel dragster develops between 4,000 and 8,000 pounds of downforce?

… that the 17-inch rear tires used on NHRA Top Fuel dragsters and Funny Cars wear out after four to six runs, or about two miles? Some brands of passenger-car tires are guaranteed for 80,000 miles.

… that it takes just 15/100ths of a second for all 7,000 horsepower of an NHRA Top Fuel dragster engine to reach the rear wheels?

… that it's desirable for an NHRA Top Fuel dragster to race with its front wheels inches off the ground for about the first 200 feet of the run? This ensures proper weight transfer to the rear wheels, a crucial part of a good launch and quick run.

… that the nitromethane used to power the engines of NHRA Top Fuel dragsters and Funny Cars costs about $30 per gallon?

Sources: NHRA Communications and Technical Departments, NHRA race teams, motorsports equipment manufacturers (and boostedpimp)
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Offline Mike52

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Re: MOTO MATHS: We can work it out ...
« Reply #42 on: May 24, 2014, 03:17:47 pm »
I dont think 100litres is correct Mike. I have heard 20-22 for a single pass. Another interesting fact is that a top fuel engine's crankshaft can twist up to 25 degrees from front to back under full load. Camshafts are set to take this into account.
Cheers, Grahame
As I said " if my memory is correct" which it probably aint.
Maybe it was the fuel cost for 4.5 secs.

If you go back in history you will find a period where the rails were doing almost the same times as now.
Space Shuttle fuel did the trick. :o
Banned it they did.
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Offline Tim754

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Re: MOTO MATHS: We can work it out ...
« Reply #43 on: May 24, 2014, 07:43:57 pm »
and like various other motor sports Aussie top fuel , prostock and top door slammer engine builders and designers are very much sort after. Why because we  are geniuses or just  "nucking futs" according to the team owners :D 8) 8) 8) 8) 8)
« Last Edit: May 24, 2014, 07:45:42 pm by Tim754 »
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Offline Lozza

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Re: MOTO MATHS: We can work it out ...
« Reply #44 on: May 24, 2014, 11:45:28 pm »
F1 car facts  up to 5G'sunder brakes up to 4G's in a corner, from 200mph to a dead stop in 65m. Has 2.5 tons of down force, like driving around with a Landcruiser strapped to the roof. Over 100mph aero drag will slow the car faster than a Bugatti Veyron can brake. Has 25mm suspension travel, with half of that in the tyre wall. Has 80,000 individual components, if the car is assembled 99.9% correct 80 components won't be in the right place. Rattle guns for the wheels consume 20,000 litres of air per min.
Fastest corner Blanchimont at Spa taken at 190mph

« Last Edit: May 24, 2014, 11:48:03 pm by Lozza »
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