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Registered:
November 2002
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Cars pulls one way when wheels spin?
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Sat, 12 June 2004 10:51
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Hi all,
As you may know, I have a semi worked 3T GTE in a TA22. It has a TRD LSD and I'm wondering why the rear end of the car pulls to the right when I lose traction?
This happens even if I'm going in a straight line? I would have thought it would just keep going straight with wheel spin?
Pretty freaky when your doing around 50km/hr in the wet and you lose traction and the car decides to swing out to the RHS.... 
Cheers,
Simon
http://users.chariot.net.au/~stmezz/celica.htm
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Location:
Montrose, VIC
Registered:
May 2002
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Re: Cars pulls one way when wheels spin?
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Sat, 12 June 2004 10:54
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The many things you discover when you drive a car with some kind of power and an LSD 
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Location:
Melbourne
Registered:
January 2003
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Re: Cars pulls one way when wheels spin?
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Sat, 12 June 2004 11:02
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Pinion Angle ? I guess its a lowered rear with standard pinion angle 50klm , try 160klm "car decides to swing out to the RHS...."
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Registered:
November 2002
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Re: Cars pulls one way when wheels spin?
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Sat, 12 June 2004 11:10
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By the sound of it, this is one of the joys of having a reasonable amonut of power?
The car is lowered 2 inches, not sure what you mean about pinion angle. I'm running a modified RA40 GT rear end. ALso the original panhard is in the bin and replaced with 2 rods connected to the diff centre, forget the exact name but it keeps the diff in exactly the same position regardless of ride height.
Simon
http://users.chariot.net.au/~stmezz/celica.htm
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I supported Toymods
Location:
Epping, Sydney
Registered:
May 2002
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Re: Cars pulls one way when wheels spin?
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Sat, 12 June 2004 11:28
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fac of life unfortunately dude.
try doing it at 120 in 4th gear in the wet
unless your diff is in the *exact* middle of the car, the diff *exactly* puts out even power, and both wheels & suspension are *exactly* the same, your car will pull to one side when the back lets go.
a little more scary than in a live axle, but you gotta deal with it 
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Location:
NSW, Sydney
Registered:
April 2004
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Re: Cars pulls one way when wheels spin?
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Sat, 12 June 2004 11:33
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the sweet joys of physics my friend!
it's called "torque steer"
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Cars pulls one way when wheels spin?
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Sat, 12 June 2004 11:40
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meh, doesn't need huge amounts of power..
as others have said, it depends on angles etc..
you will probably find that if you have a passenger who weighs same as you, the car will track straight.. and if you have a heavy bugger beside you, opposite happens..
weight transfers rearwards.. most weighted side of car gets more traction, that wheel pushes the car more, and rear pushes to that direction, as that wheel tries to spin the car about it's axis.
i have same in my old rolla, but the difference with and without passengers is huge as most ppl weigh more than 10% of my cars weight..
so basically... if you always drive alone, move weight to the passeneger side... or take a friend when you drive in the wet (if they are all too scared, pick up hitch hikers  )
Cya, Stewart
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Location:
Brisbane
Registered:
May 2002
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Location:
Adelaide
Registered:
May 2003
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Re: Cars pulls one way when wheels spin?
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Sat, 12 June 2004 15:27
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| pr1nce wrote on Sat, 12 June 2004 21:33 |
the sweet joys of physics my friend!
it's called "torque steer"
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Torque steer is generally an FWD thing attributed to the loss of torque through uneven driveshaft lengths. The slight flexion in the longer drive shaft (Toyota=Drivers side) means that one wheel applies slightly more power down. Very noticible in a GZE Rolla.
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Location:
Melbourne
Registered:
January 2003
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Re: Cars pulls one way when wheels spin?
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Sun, 13 June 2004 00:40
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It can even get more complicated than just the pinion angle , you can also go further into the center vs wheel center torque effect . I am guessing that the car has a stock length diff which the offset pinion position and length off the diff was designed for about 80hp or so at the wheels . Next it has to take three of more times that , next what happens when the torque over powers the design . The wheel is pulled of the ground so to speak by the torque forces , this is easy to control , as in the cases of drag racing setups , this force is distributed to the body of the car . Thats why front wheels come of the ground , and the looks to be twisting . In the case of track / road cars this is a little harder to engineer to stop , in a total race car easy just make the as wide as possible , eg v8 supercars etc , diff is 200mm wider than the road car . Road cars have to be a balance between the drag set up and still corner brake etc . There is a formula for this that i no doubt Old Corolla will have seen , or know of the top of his head , but apart for all this you still really will not know until you test it . So it not really Torque steer as such but it still happens do to the same forces , torque steer in fwd has been solved in the late 70's 80's by the European's , just add softly mounted engines east west design with equal length drive shafts , softer front suspension to back and unless the vehicle has to much hp for the basic fwd design you shouldn't have a problem . Live axle is unfortunately a dated design thats only benefit is its cheaper to make for the manufacturer's . Independent suspension design normally distributes this force though the complete rear suspension and subframe as well as less unsprung weight for faster reacting suspension movement so this problem is less likely to occur .
Shit all this reminders me of school , fuck Ta22 gt now i feel old .
And people ask why i want to make a irs ae86 !!
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Registered:
November 2002
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Re: Cars pulls one way when wheels spin?
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Sun, 13 June 2004 02:17
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OK guys, thanks for the responses. I try to avoid taking my beast out in the wet anyway.
Cheers,
Simon
http://users.chariot.net.au/~stmezz/celica.htm
BTW, my Celica should be in Fast Fours in the next addition if your interested....
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Location:
adelaide
Registered:
May 2002
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Re: Cars pulls one way when wheels spin?
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Sun, 13 June 2004 03:02
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yeh il be interested.. hehe
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Cars pulls one way when wheels spin?
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Sun, 13 June 2004 03:06
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| improvedae86 wrote on Sun, 13 June 2004 10:40 |
There is a formula for this that i no doubt Old Corolla will have seen , or know of the top of his head
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not really but i can make something up 
say you make 300nm, in first gear (say 3.5:1) multiplies to 1050Nm applied to tailshaft.
although this torque is usually converted to forward motion, if we assume that it all goes into trying to turn the diff into a big propeller.....
say track is 1400mm, the moment arm to each side is 0.7m
1050/0.7 = 1500N (or is it divided by two? hmm must be otherwise it would spin other way.. still this is the difference in vertical force between the tyres)
so 150kg difference in traction between the tyres.
say car weighs 900kg, 50/50/50 split = 225kg on each rear tyre..
SO.. in 1st gear, 300Nm etc etc, the 'weight' on tyres is 225+-75
= 150/300....
one side has double the traction than the other....
so if your LSD does it's job, and neither wheel spins, you still have a massive difference in force being applied by each wheel and the car spins...
but as IP86 says, with IRS, this is not an issue
Cya, Stewart
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Location:
toowoomba qld
Registered:
March 2004
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Re: Cars pulls one way when wheels spin?
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Sun, 13 June 2004 04:16
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| takai wrote on Sun, 13 June 2004 01:27 |
| pr1nce wrote on Sat, 12 June 2004 21:33 |
the sweet joys of physics my friend!
it's called "torque steer"
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Torque steer is generally an FWD thing attributed to the loss of torque through uneven driveshaft lengths. The slight flexion in the longer drive shaft (Toyota=Drivers side) means that one wheel applies slightly more power down. Very noticible in a GZE Rolla.
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would this be why my FWD drive Camry when racing it changing from 1st to 2nd chirps and pulls slightly to the left?
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Location:
Melbourne
Registered:
January 2003
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Re: Cars pulls one way when wheels spin?
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Sun, 13 June 2004 08:56
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oldcorollas
Great answer as always
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I supported Toymods
Location:
sydney.au
Registered:
August 2002
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Re: Cars pulls one way when wheels spin?
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Sun, 13 June 2004 09:02
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IP86 > punctuation dude!!
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Location:
Melbourne
Registered:
January 2003
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Re: Cars pulls one way when wheels spin?
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Sun, 13 June 2004 09:05
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| ae86drift wrote on Sun, 13 June 2004 19:02 |
IP86 > punctuation dude!!
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Haha , sorry dood , lol , i have been under a dash rewiring a bloody abortion of a 4age conversion and are still suffering from the flu .
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I supported Toymods
Location:
sydney.au
Registered:
August 2002
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Re: Cars pulls one way when wheels spin?
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Sun, 13 June 2004 09:10
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| improvedae86 wrote on Sun, 13 June 2004 19:05 |
| ae86drift wrote on Sun, 13 June 2004 19:02 |
IP86 > punctuation dude!!
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Haha , sorry dood , lol , i have been under a dash rewiring a bloody abortion of a 4age conversion and are still suffering from the flu .
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BAH! NO EXCUSES!
(no worries mate)
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) lol