Pinion Angle/Adjustable Upper Control Arms

[drogg1]

The importance of buying adjustable upper control arms is so that you can set the correct pinion angle right?

Is this because the rear yoke on the pinion needs to be parallel with the slip yoke connected to the transmission in order to prevent driveshaft vibrations?

 

[84cutspreme]

I am not sure of the best pinion angle...but I know from experience and my families racing knowledge that the yoke at the trans and the yoke at the rear Cannot be at the same level, there needs to be some angle to it.

 

[drogg1]

If the two yokes are not parallel to one another this will cause vibration. It has to do with the shaft accelerating and deccelerating several times a rotation. I'm just asking if having the correct pinion angle has to with this same theory.

 

[84cutspreme]

Sorry, I misunderstood.

 

[88olds421]

If I am correct adjusting the pinion angle from what it was stock on the car will change the instant center of the car during the launch. If you adjust to a couple of degrees negative pinion angle it will tend to plant the tires harder at launch than with no angle.

 

[86 regal]

i was told once that there is supposed to be 3 degreese difference between the pinion yoke and the driveshaft

 

[pontiacgp]

if you read up on pinion angle settings experts have varying opinions on setting the angle so I would use that online info to help you set the angle you prefer.

 

[88olds421]

I have a set of Southside Machine lift bars and upper control arms on my cutlass. In following hte directions they called for a 3 to 5 degree negative pinion angle to best load the rear suspension before a launch and in this range there isn't so much angle between the driveshaft and pinion to eat up u joints.

 

[megaladon6]

pinion angle on a street car is for vibration damping. on a race car it's set so that when the suspension is loaded and twists, the driveshaft is straight allowing for greater power transfer. g-body's have a 4link suspension which is very rigid. they require very little pinion angle.

 

[pontiacgp]

The other thing is on an asphalt circle track car the ground clearance and the suspension travel are usually much less than on a street car so the pinion angle doesn't change as much.