Just did the math. (1 Viewer)
- Thread starter Husky
- Start date
The Counterfeiter
Nitro Member
Mike - I also love this stuff! My math says Tony's motor turned over 589 times during "The Run" -
Can ya figure out how many times the slicks rotate during a successful pass?When you look at a fuel car pass from this perspective, it's easy to understand why tuners are walking a tightrope. And, of course, we haven't addressed slide valves, clutch cannons and timing curves -
Nitrohaulic
Nitro Member
What's even more amazing to me. If the spark plug fires 75 times a second, that piston does 300 strokes a second. Times eight would be 2,400 for all of them.
There's an interesting one for someone to work out. How much distance do ALL the pistons have to travel for a particular car to make a quarter mile run? Just base it on the engine's average RPM for the pass?
Reminds me of when people would ask Warren Johnon questions like "If you dropped a pro stock car from a tree limb at "X" distance, at what speed would it contact the ground?" and he'd spend a whole back page in ND explaining the answer, factoring in whether it tumbled or not, etc.
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jpee
Nitro Member
Thats an interesting question... what is the overall diameter of a TF tire when its fully expanded.. how many times will it rotate to cover the 1/4 assuming there is NO spin.. I don't think its very many...
Nitrohaulic
Nitro Member
Wait, was Alan's "75 sparks a second" WITH an MSD? LOL (multiple spark discharge unit). Would fire a lot more times than that, actually.
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Nitrohaulic
Nitro Member
Sure. 1,320 divided by the tire's circumference plus the number of revolutions it slips.
Turtle
Nitro Member
Sure. 1,320 divided by the tire's circumference plus the number of revolutions it slips.
But the circumference of the tyre at the beginning of the run compared to the end of a run would be different.
willy
Nitro Member
LOL..that takes a special calculator.
Good one Arthur
This math gives me a headache..
Nitrohaulic
Nitro Member
But the circumference of the tyre at the beginning of the run compared to the end of a run would be different.
You're right. I left out the variable term "give or take a revolution."
Outlaw Eric
Nitro Member
Don't forget to account for the fact that the clutch doesn't fully engage until nearly the end of the track.
It 'might' be better to figure the average RPM of the engine 8200(?) X 4.5 seconds = 615 revolutions.
Either way it is madness!
scotty
Nitro Member
This is a dangerous thread ...could spend hours on the unbelievable physics of fast drag cars.
Alan - the coil firing 600 times/sec really makes a good argument for the independent coils on the PST engines because at the 10500 those things turned, that's 700 times/sec.
Using the 105" rollout that Nunzio mentioned, that's about 150 revolutions to cover 1320 ft with NO slip. Since we know the rollout at the top end is larger than that (10% increase would be 115" or so) then the revolutions would be less but then you account for a "blacktracking" car and the revs go right back to around 150.
The one that always gets to me is the 60ft accelerations of the fuel guys. These days a slow 60 is 0.950? A good one is 0.850? At 0.950 that's about 4.1 g's and at 0.850 that's 5.1 g's!!! To put that in perspective think of lying on a hard floor and having 4 more people your weight lie on top of you, that's 5 gs. And I have good reason to believe it's more than that right before 60ft. Now imagine it shakes and you have to move 5x your arm and actually grab the brake, steer, pedal, etc and it really shows what the drivers go through and the value of the good ones.
Alan - the coil firing 600 times/sec really makes a good argument for the independent coils on the PST engines because at the 10500 those things turned, that's 700 times/sec.
Using the 105" rollout that Nunzio mentioned, that's about 150 revolutions to cover 1320 ft with NO slip. Since we know the rollout at the top end is larger than that (10% increase would be 115" or so) then the revolutions would be less but then you account for a "blacktracking" car and the revs go right back to around 150.
The one that always gets to me is the 60ft accelerations of the fuel guys. These days a slow 60 is 0.950? A good one is 0.850? At 0.950 that's about 4.1 g's and at 0.850 that's 5.1 g's!!! To put that in perspective think of lying on a hard floor and having 4 more people your weight lie on top of you, that's 5 gs. And I have good reason to believe it's more than that right before 60ft. Now imagine it shakes and you have to move 5x your arm and actually grab the brake, steer, pedal, etc and it really shows what the drivers go through and the value of the good ones.
willy
Nitro Member
What do you think would be the physical limitations?
Are we nearing that?
Detached retinas have already been an issue, etc.
Einstein had a theory, eh? The body is only capable of covering so much ground in so much time that things start to happen, ya know like 'Back to the Future'..hehe..poof.
Are we nearing that?
Detached retinas have already been an issue, etc.
Einstein had a theory, eh? The body is only capable of covering so much ground in so much time that things start to happen, ya know like 'Back to the Future'..hehe..poof.
