Pinion angle

[bsm126]

I have an 02 black front rocket and ive been trying to set the pinion angle but the most angle I can get is 6 degrees before the pinion mount hits the 5th link. Im wondering what I have to do to get more angle. Thanks

[swingarm4life]

You can either order a pinion plate thats notched for the ladder bar or grind a notch in yours. Its best to get the ladder bar that has the bend in it so that you can lower your panhard to the bottom of the pinion or below if you need to. Why would you want much more than 6 degrees anyway?

[bsm126]

My rocket setup book says to start out at 7 degrees. Ive also heard of some guys running as high as 9 degrees. Dont know what the benefit of that is but ive heard of it.

[hpmaster]

Are you adding driveshaft angle to pinion angle to get 7 degrees? Many times I have seen guys having trouble is when they put the angle gauge on the pinion plate and try to set that to 7 degrees, not taking into consideration the driveshaft angle of 2.5 to 4 degrees or so to start with. What I do is get the driveshaft angle then add the pinion angle to get your 7 or whatever. I have seen chassis dyno test runs where they set pinion angle to reduce HP loss, not builder specs.

[JJRT]

how does it prevent horsepower loss ?

[hpmaster]

how does it prevent horsepower loss ?

By setting shaft to be as straight as possiable under load so you don't use HP to move roller bearings to adjust for angle under full load. The loss is not great but does happen, 10 to 15 hp as I remember. By straight as possiable at full load but it can't be too straight or you can ruin the needle bearings because of no load on them, just like you ruin them with too much angle and load. This horsepower loss is part of what is called parasitic loss in the drivetrain. This loss starts with how the transmission is aligned to the engine all the way back to the bearings on the axles and finaly the seals and their drag plus every bearing surface and gear matting surface in between. As for drive angles like everything else there are therories, such as matching the load angles of both front and rear u joints to be working at the same angle under full load. But just as soon as you think you have that all figured out most late models when you move a engine right or left you set up what is called a 2 plane driveshaft, with the drive shaft angled not only up and down but right and left. Talk to chassis dyno operators, its part of trying to get every last drop of power out a car you can.