question about adjusting torque arm
Thread Starter
Joined: Mar 2003
Posts: 8,319
Likes: 1
From: North Carolina
question about adjusting torque arm im thinking about getting a spohn torque arm soon. but im just wondering how im gonna fit under the car to get to it lol. i assume that the wheels need to be on the ground for the right measurement. so how do you get it adjusted right?
also, with the car being lowered, what is the correct setting for the pinion angle? or is this something that will be cleared up with the angle finder? i really have no clue, never set one up before
also, with the car being lowered, what is the correct setting for the pinion angle? or is this something that will be cleared up with the angle finder? i really have no clue, never set one up before
TECH Fanatic
Joined: Nov 2004
Posts: 1,118
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From: TX
I'm a skinny guy with long arms, so i was just able to adjust mine with some minor contortions. But my car isnt lowered. If you can't do it in a driveway, get under it with an oil change pit or a drive on lift. As for how to set the angle. You just have to think things through. Think about why you're getting the torque arm.
You should be thinking "cuz the stocker is weak and when i launch hard, the rear axle tries to rotate the opposite direction the wheels are going (its true, just think about it) and the torque arms job is to stop the axle from rotating or 'torqueing'. So since the stocker is weak, it absorbs grunt that could be going into a nice hard launch by its flexing. So this is why you want a stiffer torque arm. Then you think, ahh, but bushings and even beefy steel can still flex, so this is what i need an adjustment for because when i'm in a hard launch, i want the driveline to be nice and straight so nothing binds because i dont want to be robbed of power or break something. So i want to angle the pinion down so it comes close to 0 degrees (aka straight) under hard launches, when its most critical, that way the rest of the time its only a degree or 2 off from straight, but that wont hurt anything because you're not on it hard the rest of the time. The key is, you want the driveshaft angle and the pinion angle to be the same when the axle is under hard torque, so to do this you want to figure how much flex you're going to have and compensate for it by having a 'V' angle (NOT a '^' angle) where the difference is 1 to 3 degrees depending on your setup. I know its challenging concept to grasp for some, but amidst all of the shade tree methods rule's of thumb and lay-mans instruction sheets, there is plain old reasoning
You should be thinking "cuz the stocker is weak and when i launch hard, the rear axle tries to rotate the opposite direction the wheels are going (its true, just think about it) and the torque arms job is to stop the axle from rotating or 'torqueing'. So since the stocker is weak, it absorbs grunt that could be going into a nice hard launch by its flexing. So this is why you want a stiffer torque arm. Then you think, ahh, but bushings and even beefy steel can still flex, so this is what i need an adjustment for because when i'm in a hard launch, i want the driveline to be nice and straight so nothing binds because i dont want to be robbed of power or break something. So i want to angle the pinion down so it comes close to 0 degrees (aka straight) under hard launches, when its most critical, that way the rest of the time its only a degree or 2 off from straight, but that wont hurt anything because you're not on it hard the rest of the time. The key is, you want the driveshaft angle and the pinion angle to be the same when the axle is under hard torque, so to do this you want to figure how much flex you're going to have and compensate for it by having a 'V' angle (NOT a '^' angle) where the difference is 1 to 3 degrees depending on your setup. I know its challenging concept to grasp for some, but amidst all of the shade tree methods rule's of thumb and lay-mans instruction sheets, there is plain old reasoning
Thread Starter
Joined: Mar 2003
Posts: 8,319
Likes: 1
From: North Carolina
yea i know what the torque arm does and the set up of it and that whole deal. i just have no idea how you set them up lol. i am assuming that no matter if the car is lowered or not, that the angle will be set right with the tool on there? i was told 0 deg for street and -2 for the strip. -2 of course like you said the hard launch will bring that close to 0 again.
think i might get that relocation bracket at the same time i do the torque arm. last thing i want to do is have to deal with a broken tranny
think i might get that relocation bracket at the same time i do the torque arm. last thing i want to do is have to deal with a broken tranny
TECH Fanatic
Joined: Nov 2004
Posts: 1,118
Likes: 0
From: TX
You put the angle finder on the driveshaft and on the lower plate that bolts to the diff. The fact that your car is lowered is really of little consequence in terms of pinion angle adjustment, thats the deal with a torque arm setup over a 4-bar setup or other varieties is that the pinion angle stays more or less the same through the normal travel range of the rear suspension. Relocating the torque arm mounting point sorta changes the geometry a little, but the bmr crossmember wont relocate it enough for it to be a concern, it pretty much puts back in the stock position (only, not on the trans). Other chassis-mount torque arms have more of an affect on the geometry.
