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Old 10-12-2003, 07:18 PM   #1
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Default how do you calculate your top speed??????

does this sound right to use this form....take and measure off 100 or how many ever feet you want to try...and time it ...and then divide your time by your feet and multiply it by .68 to get your top speed?
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Old 10-12-2003, 09:54 PM   #2
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i tried this at 50 feet today and came up with about 35 mph i dont know if that is really how it is done or not i read somewhere that this was the way to calculate it...i just wanted to get you guys opinions..i have a hpi rs4 3 ss with stock gearing right now and i read the car will run 46mph with stock gearing so i dont know
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Old 10-12-2003, 11:46 PM   #3
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Your math should be correct...

If your RS4 has old worn down tires, it won't go a fast as it would with brand new, bigger diameter tires. Or maybe your engine could be leaned out just a weeee little bit more.
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Old 10-13-2003, 12:05 AM   #4
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Math is correct, but you aren't getting your max speed, only the average. To get your max speed, you'll have to hit the distance markers going near full throttle/top speed, and take the time it takes for you to make it from to the other. If you start from a stop, or even going half speed, it will still give you the average of your speed over that interval. You could always just try and get the "theoretical" top speed using this equation:

Estimated Top Speed = (Engine RPM (max) / Final Drive Ratio) * (Tire Diameter/336.135)

You can assume most nitro engines to hit around 32000-36000RPM
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Old 10-13-2003, 12:27 AM   #5
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excellent formula i was doing the long math in ft ft per mile 60 mins............comes out the same gonna write this one down
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Old 10-13-2003, 08:32 AM   #6
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thanks guys for the help..yeah my tires are about half worn i didnt really take that in to consideration when i done this last night...and i done it at lowes and it was very slick there..
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Old 10-13-2003, 08:43 AM   #7
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i was also gonna use this formula with different bodies just to see how much or how little they make a difference
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Old 10-16-2003, 02:15 AM   #8
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speed and gear ratio calculator......
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Old 10-16-2003, 02:18 AM   #9
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this way please...
http://f1.grp.yahoofs.com/v1/AFCOP8m...6aWc5GOlVPISnE
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Old 10-16-2003, 12:32 PM   #10
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i couldnt get your url to work
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