Physics and equations of top speed+torque!!!  
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Physics and equations of top speed+torque!!! - 4/14/2008 10:02:28 AM   
GYNAIKAS



Posts: 3606
Joined: 9/14/2006
From: Athens/Patras, GREECE
Status: offline 		I did the project as Impulce requested. Since RCU was under maintainace I did it on paper...and you know I''m lazy (I don''t have a scanner too) so here you go! Pm me for any questions.

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RE: Physics and equations of top speed+torque!!! - 4/14/2008 2:34:46 PM   
ziggy12345


 

Posts: 283
Joined: 6/20/2003
From: UK
Status: offline 		What on earth is all that hieroglyphics??

Put the lot into a spreadsheet so the user can adjust the inputs and see th results.

Cheers

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RE: Physics and equations of top speed+torque!!! - 4/14/2008 2:51:43 PM   
GYNAIKAS



Posts: 3606
Joined: 9/14/2006
From: Athens/Patras, GREECE
Status: offline 		Honestly it''s the simplest it can be...I explaining everything step by step and in the end there''s the final formula for calculations. I also write what every single variable represents. Give it a try and you''ll understand for sure.

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RE: Physics and equations of top speed+torque!!! - 4/14/2008 7:13:53 PM   
Cypriot Boy


 

Posts: 692
Joined: 1/18/2007
From: Nicosia, CYPRUS
Status: offline 		WOW that a lot of math and calculations!!! just trying to undersand!!!

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RE: Physics and equations of top speed+torque!!! - 4/14/2008 7:22:12 PM   
773W


 

Posts: 139
Joined: 11/27/2007
From: CL, AB, CANADA
Status: offline 		Here''s one of the calcs i did up a while ago. (R/C)= fun/smiles!!

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RE: Physics and equations of top speed+torque!!! - 4/14/2008 7:29:57 PM   
dsales



Posts: 524
Joined: 8/14/2005
From: London, UNITED KINGDOM
Status: offline 		Can you put all this quantum mechanics into simple English please

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RE: Physics and equations of top speed+torque!!! - 4/14/2008 7:41:33 PM   
GYNAIKAS



Posts: 3606
Joined: 9/14/2006
From: Athens/Patras, GREECE
Status: offline 		Quantum mechanics? Well they were teaching us these things at high schooll and i can show you a 3rd grade book if you don''t believe me (it must be somewhere in a bookshelf...it''s been 6years till I last saw it, LOL)! Honestly there''s nothing hard if you spend some time reading it all. If you trust me rely on the final equations. All the other stuff is simply the mathematical documentation of the final equations on each page.

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I simply love perfection...do something as good as you can or don't do it at all...

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RE: Physics and equations of top speed+torque!!! - 4/14/2008 8:02:12 PM   
GYNAIKAS



Posts: 3606
Joined: 9/14/2006
From: Athens/Patras, GREECE
Status: offline 		Let me give you a brief example. My engine revs at 38000rpm max. So (rpm)e = 38000 r/min (hpiracing sais 40000 out of the nitro star 18ss but I don''t believe them.LRP z.18 makes 36000 but mine is modified so I''m almost sure that it revs somewhere around 38000 practical). I use 23T pinion (2nd gear) and 43T spur. So T1=23 and T2=43. Also the final gears are Tf1=13 and Tf2=38. Also the wheel radius of my current wheels (rim+tire) is 3.4cm. So Rw=3.4

Vmax = 0.003768*((T1*Tf1*Rw)/(T2*Tf2))*(rpm)e => Vmax=0.003768*((23*13*3.4)/(43*38))*38000 => Vmax = 89.0825 [Km/h]

To convert that in mph: Vmax[mph] = 0.62*Vmax[km/h] => Vmax[mph] = 0.62*89.0825[km/h] => Vmax[mph] = 55.23mph

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RE: Physics and equations of top speed+torque!!! - 4/14/2008 8:12:21 PM   
dsales



Posts: 524
Joined: 8/14/2005
From: London, UNITED KINGDOM
Status: offline 		Ok, I finally get it

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RE: Physics and equations of top speed+torque!!! - 4/14/2008 8:18:46 PM   
GYNAIKAS



Posts: 3606
Joined: 9/14/2006
From: Athens/Patras, GREECE
Status: offline 		Another example: Fot the same car (same max rpm, same final gear ratio) What gearing do I need to get to 70mph if I''ve already found bigger foamies (larger radius->more top speed), let''s say with 4cm radius (the ones that miami guys use)??? (searching for the T1/T2 ratio)

Solution:
We have to calculate backwards. With easy modifications I rebuild the equation: Vmax[mph]=0.62*Vmax[km/h] => Vmax[km/h] = 70mph/0.62 = 112.9km/h

(T1/T2) = (Vmax*Tf2)/(0.003768*(rpm)e*Tf1*Rw) => (T1/T2) = (112.9*38)/(0.003768*38000*13*4) => (T1/T2) = 0.57621

So for the current T1 pinion gear (23T) I need T2=39.916T wich means that using the HPI 39T spur gear will boost the car above 70mph!!!

FEAR TRAXXAS!!!

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RE: Physics and equations of top speed+torque!!! - 4/14/2008 8:33:44 PM   
dsales



Posts: 524
Joined: 8/14/2005
From: London, UNITED KINGDOM
Status: offline 		...Or a could just save time and buy a schumacher fusion and completely destroy you

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RE: Physics and equations of top speed+torque!!! - 4/14/2008 8:41:00 PM   
GYNAIKAS



Posts: 3606
Joined: 9/14/2006
From: Athens/Patras, GREECE
Status: offline 		Till the first corner ...then the fusion yould be somewhere out of the track...and the RS4 still running. And if the fusion managed to corner the RS4 corners 3 times faster!!!

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I simply love perfection...do something as good as you can or don't do it at all...

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RE: Physics and equations of top speed+torque!!! - 4/14/2008 8:53:08 PM   
Danker16


 

Posts: 187
Joined: 7/20/2006
From: brampton, ON, CANADA
Status: offline 		yo thanks man i have been looking for something similar to get a top speed of my OS 18TM, it looks pretty simple actually.!

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RE: Physics and equations of top speed+torque!!! - 4/14/2008 9:35:00 PM   
GYNAIKAS



Posts: 3606
Joined: 9/14/2006
From: Athens/Patras, GREECE
Status: offline 		No problem! I like physics...brain training...

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I simply love perfection...do something as good as you can or don't do it at all...

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RE: Physics and equations of top speed+torque!!! - 4/14/2008 11:20:05 PM   
ferrarimk13



Posts: 3538
Joined: 12/17/2005
From: Staten Island, NY, USA
Status: offline 		man, is this what ill have to look forward to in AP physics? thanks for making it though, ill re read it and try to understand.

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RE: Physics and equations of top speed+torque!!! - 4/15/2008 12:13:45 AM   
GYNAIKAS



Posts: 3606
Joined: 9/14/2006
From: Athens/Patras, GREECE
Status: offline 		Physics is easy once you open your mind and realise that you can do magic things with it! It''s really several times easier than it looks!

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I simply love perfection...do something as good as you can or don't do it at all...

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