Wheels in air dont rotate : Why ?

worrisomebear · 19th April 2007, 11:55

hi friends,

i was watching a video of some cars pulling stunts like driving on 2 wheels. no not a wheelie. they were like driving on two left wheels. im sure u have seen this before. now the thing is both the right side wheels (which were in the air, did not rotate.) why is it so.

first i thought maybe cuz of differential unit. then i read that in differential, same torque is supplied to both wheels but rotation speed is different. wheel with less friction rotates faster.

in that case the wheel in the air should rotate even faster. why is it stationary? also confirm if differential unit is present on both the axles.

esteem_lover · 19th April 2007, 12:17

Could it be simply because there was no acceleration, hence no power transmitted to the wheels ?

arunforu1 · 19th April 2007, 12:34

Quote:

Originally Posted by worrisomebear

hi friends,

wheel with less friction rotates faster.

in that case the wheel in the air should rotate even faster. why is it stationary? also confirm if differential unit is present on both the axles.

Differential unit is present only on live axle, if it is a 4wd then only diiferentials are there on both axles as both are live, in addition to a transfer case.

You are right the wheel in air, owing to less restriction should spin more, unless there is a specific arrangement for locking the wheel in air, so as to transmit whole power to wheel in contact with graound.

worrisomebear · 19th April 2007, 13:50

myself confused right now..i dnt know why

sbasak · 19th April 2007, 13:58

Most probably they are governed by TORque SENsing Differential
It sends 100% of available torque to the wheel which has the traction (i.e. to the wheel in the ground in this case).

Search in Google for Torsen differential and you'll get lots of info.

Example
Torsen General Frequently Asked Questions page

Technocrat · 19th April 2007, 14:42

I think this kind of setup is available even in the Mitsubishi EVO remember hearing something like this in a TG video.

rishibravo · 19th April 2007, 15:40

i think it happens in all the cars and the reason is differential.

Technocrat · 19th April 2007, 15:54

Sar because of differential only the wheel should move. plese ready previous posts. Unless it has the TORque SENsing Differential as stated by sbasak the wheel should rotate

SLK · 19th April 2007, 15:58

If differential was the answer.. the wheel in air is the only one that is supposed to move...

I say its just the momentum of the car... they pick up speed... and while doing the stunt don't accelerate at all... just let it roll.

Otherwise if the wheels in air are completely stopped... they might have some kind of a single sided brake!

v1p3r · 19th April 2007, 16:58

Limited slip differential. Or zero throttle.

Jomz · 19th April 2007, 17:47

Quote:

Originally Posted by v1p3r

Limited slip differential. Or zero throttle.

With Limited slip differential it should rotate right..

ananthkamath · 19th April 2007, 18:29

Quote:

Originally Posted by sbasak

Most probably they are governed by TORque SENsing Differential
It sends 100% of available torque to the wheel which has the traction (i.e. to the wheel in the ground in this case).

Search in Google for Torsen differential and you'll get lots of info.

Example
Torsen General Frequently Asked Questions page

wrong, the torsen doesnt work when one of the wheels is in the air.

nitrous · 19th April 2007, 18:42

Differential lock is one probable reason.

v1p3r · 19th April 2007, 19:15

Quote:

Originally Posted by Jomz

With Limited slip differential it should rotate right..

No. With an LSD the wheel in the air won't rotate. Torque is supplied to the wheel that has traction.

But in this case, it's 99% because they are cruising with zero throttle.

headers · 19th April 2007, 19:17

camera trick is the answer.

As many of you pointed out..the wheel in the air is supposed to rotate faster than the one on the road. Any kind of diff including Diff lock..WILL make the wheel rotate and NOT otherwise..

19th April 2007, 11:55	#1
worrisomebear BHPian Join Date: Sep 2005 Location: Mumbai, London Posts: 54 Thanked: 9 Times	Wheels in air dont rotate : Why ? hi friends, i was watching a video of some cars pulling stunts like driving on 2 wheels. no not a wheelie. they were like driving on two left wheels. im sure u have seen this before. now the thing is both the right side wheels (which were in the air, did not rotate.) why is it so. first i thought maybe cuz of differential unit. then i read that in differential, same torque is supplied to both wheels but rotation speed is different. wheel with less friction rotates faster. in that case the wheel in the air should rotate even faster. why is it stationary? also confirm if differential unit is present on both the axles.
	() Thanks

19th April 2007, 12:17	#2
esteem_lover Senior - BHPian Join Date: Jul 2006 Location: Madras/Py Posts: 7,556 Thanked: 502 Times View My Garage	Could it be simply because there was no acceleration, hence no power transmitted to the wheels ?
	() Thanks

19th April 2007, 13:50	#4
worrisomebear BHPian Join Date: Sep 2005 Location: Mumbai, London Posts: 54 Thanked: 9 Times	myself confused right now..i dnt know why
	() Thanks

19th April 2007, 13:58	#5
sbasak BHPian Join Date: Nov 2005 Location: CCU-LTN Posts: 608 Thanked: 14 Times	Most probably they are governed by TORque SENsing Differential It sends 100% of available torque to the wheel which has the traction (i.e. to the wheel in the ground in this case). Search in Google for Torsen differential and you'll get lots of info. Example Torsen General Frequently Asked Questions page Last edited by sbasak : 19th April 2007 at 13:59.
	() Thanks

19th April 2007, 14:42	#6
Technocrat Senior - BHPian Join Date: Feb 2004 Location: GTA Posts: 14,813 Thanked: 2,700 Times	I think this kind of setup is available even in the Mitsubishi EVO remember hearing something like this in a TG video.
	() Thanks

19th April 2007, 15:40	#7
rishibravo BHPian Join Date: Jul 2006 Location: New Delhi Posts: 579 Thanked: 11 Times View My Garage	i think it happens in all the cars and the reason is differential.
	() Thanks

19th April 2007, 15:54	#8
Technocrat Senior - BHPian Join Date: Feb 2004 Location: GTA Posts: 14,813 Thanked: 2,700 Times	Sar because of differential only the wheel should move. plese ready previous posts. Unless it has the TORque SENsing Differential as stated by sbasak the wheel should rotate
	() Thanks

19th April 2007, 15:58	#9
SLK Senior - BHPian Join Date: Feb 2004 Location: DL XX XX XXXX Posts: 1,634 Thanked: 1,011 Times	If differential was the answer.. the wheel in air is the only one that is supposed to move... I say its just the momentum of the car... they pick up speed... and while doing the stunt don't accelerate at all... just let it roll. Otherwise if the wheels in air are completely stopped... they might have some kind of a single sided brake!
	() Thanks

19th April 2007, 16:58	#10
v1p3r Senior - BHPian Join Date: Feb 2005 Location: BLR / DXB / LON Posts: 5,334 Thanked: 6,896 Times View My Garage	Limited slip differential. Or zero throttle.
	() Thanks

19th April 2007, 18:42	#13
nitrous Senior - BHPian Join Date: May 2004 Location: UAE/Lon/Madras Posts: 6,965 Thanked: 325 Times View My Garage	Differential lock is one probable reason.
	() Thanks

19th April 2007, 19:17	#15
headers Senior - BHPian Join Date: May 2006 Location: Greater Chennai Posts: 4,667 Thanked: 559 Times	camera trick is the answer. As many of you pointed out..the wheel in the air is supposed to rotate faster than the one on the road. Any kind of diff including Diff lock..WILL make the wheel rotate and NOT otherwise..
	() Thanks