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Discussion Starter · #1 ·
Ok... so lets say we burn some rubber... that means the torque from the engine is greater than the Static frictional force from the ground to the tire.

At this point, when the tire breaks free, the torque is the greatest on the shafts. Right before the tire breaks free, the shaft will break(if the frictional force is great enuf)

Therefore it matters not what torque the engine produces, but what force the friction is placing on the driveshafts, making them twist and break.

Anyone find error in this ASSumption?



Ive been taking physics to heart... to much.
 

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Not exactly. Turn the telescope around, you're looking through the wrong end.
The frictional force is like inertia. It only resists change. If no force is applied, nothing happens. The force generated by the engine's torque multiplied by the reduction factors of the transmission gear and final drive gear are what the friction is resisting, so the axle will only wind up as much as the force applied by the engine and drivetrain.

Unlike inertia, the frictional force can be overcome by applying more force than the contact patch will resist, this is when the tire starts slipping and if you apply enough force in excess of the tire's ability to resist, the tire will spin freely.

The driveshafts break because for a moment in time the force applied by the engine and drivetrain exceeds the axle's ability to resist damage. This also means you have to have a tire that will resist more force than the axle will resist, which is why so far this seems to only happen with slicks at the track.

The big concern is, if this is happening instantly with slicks, will it also happen over time with street tires? This is not because they resist sufficiently, but because repeated applications of force tend to cause similar damage, just not as quickly. So if they break instantly with slicks, maybe they will only last 40 or 50 launches with a good street tire before they suffer catastrophic failure. No one knows the answer to that question today. Lots of speculation, but no hard answers. This answer is not a hard answer either, it is a SWAG. Scientific Wild Ass Guess.
 

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Ironhead
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ah, answers i can wrap my head around. thanks, lance.

swag for me while in the service was used to classify targets via broadband signatures. as in, "contact bearing 220 is making 85 turns per minute on a 3 bladed screw. classified trawler."

Sonar's Wild Ass Guess.
 

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Discussion Starter · #4 ·
Ok... lets say the largest amount of twisting force on the axle is in first gear. So we drop teh clutch from 3k rpms and we burn some rubber, but then we drop it from 5k rpms and BAM there goes a drive shaft.

Am I correct to assume that the force needed to spin the tire up to 5k rpm is greater than the force needed to spin it up to 3k rpm?


I thought, in each case, we were just dealing with overcoming static friction, and not the force needed to spin the tire.



Another thing: As a tire rotates, does it put a centrifugal force on the ground from the tire? kinda like you on a tilt-o-whirl? And at higher speeds, the force should be greater, making the fiction between the tires greater and boosting preformance.
 

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Originally posted by QuadinScionTC@Nov 10 2005, 09:37 AM
As a tire rotates, does it put a centrifugal force on the ground from the tire? kinda like you on a tilt-o-whirl? And at higher speeds, the force should be greater, making the fiction between the tires greater and boosting preformance.
[nitpick]
There is no such thing as centrifugal force. It is call centrical. Centrifuges are a mis-nomer.
[/nitpick]
 

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Discussion Starter · #6 ·
Originally posted by Plissken+Nov 10 2005, 07:06 PM-->QUOTE (Plissken @ Nov 10 2005, 07:06 PM)
<!--QuoteBegin-QuadinScionTC
@Nov 10 2005, 09:37 AM
As a tire rotates, does it put a centrifugal force on the ground from the tire? kinda like you on a tilt-o-whirl? And at higher speeds, the force should be greater, making the fiction between the tires greater and boosting preformance.
[nitpick]
There is no such thing as centrifugal force. It is call centrical. Centrifuges are a mis-nomer.
[/nitpick] [/b]
LOL i was going to say centripedal, but i thought most people would understand centrifugal.

[nitpick]Centrifugal does exist in a non-Inertia refrence frame[/nitpick]
 
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