Spohn Torque Arm Install Question
06-25-2006, 09:31 PM
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Spohn Torque Arm Install Question I installed the Spohn TA today. Not a bad install. Problem comes in with pinion angle. I used the angle finder that Spohn sent with the ta. Heres the problem: I get two different angles depending on which side of the car I read the angle finder. If I read it from the driver side I get -2 on the ds and -2 on the dif. housing. To me that is 0. If I go to the passenger side, I get 3 1/2 on the ds and 2 1/2 on the dif. housing. That is +1 degree. Which side do you read this from? After making the assumption that it is from the driver side (could be wrong assumption) I took car out for a ride and had a vibration in the seat at low speeds. I looked under the car and one thing I see is the y-pipe is right against the ds loop, but I don't think that is causing the vibration. Anybody have any ideas?
06-26-2006, 01:07 AM
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i belive that it is from the driver side but i can be wrong, here's a link maybe it will help http://www.go-fast.org/z28/pinionangle.html
06-28-2006, 09:53 AM
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don't adjust your pinion angle using your driveshaft, as this will not correctly set your pinion angle to match your tranny output angle. If these angles are not the same or close to the same, you will get high speed vibrations.
I just installed a Spohn adjustable TA as I had a high speed vibration and found out I had a difference of 4 degrees between my tranny output shaft angle and pinion angle. I adjusted my new TA so my pinion angle matched my tranny output shaft angle and it made a big difference!!!! No more of that cyclical high speed vibration.
BTW, I measured all my angles from the drivers side.
http://www.streetissuecustoms.com/pinionangle.html
This is what I did:
I just installed a Spohn adjustable TA as I had a high speed vibration and found out I had a difference of 4 degrees between my tranny output shaft angle and pinion angle. I adjusted my new TA so my pinion angle matched my tranny output shaft angle and it made a big difference!!!! No more of that cyclical high speed vibration.
BTW, I measured all my angles from the drivers side.
http://www.streetissuecustoms.com/pinionangle.html
This is what I did:
Measure angles from same side of car. First measure angle at face of crank pulley. This is normal to crank shaft which is parallel to trans shaft. Then measure angle at face of pinion yoke. This is normal to pinion. I want these angles to be the same when the car is under load. From this point while the car is at rest, you adjust the torque arm to move the pinion downward between 0 and 2 degrees depending on your intended usage. Some even go to 3 degrees for racing. Mine is pretty finicky and I get vibration if I go past -1 degree. This downward adjustment is to account for suspension loading while under load. Less angle for highway cruising, more angle for drag racing. Different angles to accomodate different suspension loads. Maximum power is transferred through the drivetrain when the pinion is parallel to the crankshaft at any given load condition--just depends on what you want to optimize for. FYI -- The crankshaft and trans mainshaft are parallel by design (the engine and trans are bolted together).
