Quick Wishbone Question

I'm building my wishbone and have a question. I've read to have atleast a 35 degree angle. Is that from the frame to the side of the wishbone? Is at least 35 necessary? To have the two tubes join near the front link im right around 27 degrees. If if move the bars down a little from the front link it will increase the angle but i didnt know if that is ok to have roughly a 6" tube going to the crossmember. Here is a pic of what im talking about...
 

Jason that frame is looking sick man. My thoughts are ( because I'm backhalfing mine soon and doing a wishbone) that if you were to draw a straight line down the side of your lower bars at ride height toward the front of the truck, then draw a straight line down the side of your wishbone the two lines should meet at your front bumper. Thats what I was always told, it's going to be different for every type of truck because of the length of the truck. Someone on here with alot more experience than me might have some mathmatical other worldly geometry that is right on but thats my two cents. Hurry up and get that thing done so I can paint it! 

Jason the 35° rule is for a triangulated 4link, a wishbone setup usually doesnt follow these rules. Basically the longer the bars, the wider you want the wishbone, so I would push those bar ends on the axle as close to the frame as you can go. Also thats a very good choice using a "super pivot" joint, will def help with articulation.   Mike the measurements youre descibing have to do with instant center. It is said that a good neutral IC is around the front bumper of a vehicle.

Thanks for the help guys. This is my first time building a frame or a link setup but its going pretty smooth so far.

Turn the "super pivot" so the bolt is vertical. This is a practice that needs to be done more often. If it is a super pivot, it will have plenty of travel in it. It will be twice as strong with the bolt vertical. The loading on a wishbone is coming from the side (the wishbone controls the side to side tracking of your rear end), if you run the bolt horizontal it wants to push the ball out the side. If you run the bolt vertical it will push the ball into the side of the ball cup, thus being stronger.   As far as seperation angles (the V) of the wishbone tubes, you want it as wide as possible. There are a lot of things that can limit this, so just stick with as wide as possible.   As far as horizontal angles go, like some one already said... you want the imaginary, extended lines to intersect. Depending on where they intersect will determine how your rear end responds when you get on the gas. They should intersect around the front of the motor, and stay close in height to the front of the crank shaft. So if you aim for your pulley on the crankshaft, that would be perfect.

the purpose of the wishbone is to center the rear end and keep it from moving side to side correct? Seems like with this super pivot i am not going to accomplish this . Am i just losing my mind and over thinking this or am i doing something wrong??? It just looks like the only thing holding it from side to side is the lower bars because of the major pivot on the upper.   I guess i dont understand teh vertical bolt on the super pivot. That seems like it would bind up at lift. I'm not majorly concerned with lift but i need quite a bit to untuck my 24's. Do you have a "how to vertical super pivot for dummies clif notes"

Edited: 3/5/2009 8:10:28 PM by TwistedMinis

Here's one I did with a vertical mounted bolt.  I used a 3/4" rod end with 9/16" misalignment spacers. The bar is less than 30" long, and it cycles roughly 2 feet at the axle. Much more than you should need travel wise. And the pivot joint should travel further than that. It is definitely stronger mounted this way, but not entirely necessary for street driven use.

i need roughly 12-13" of lift to untuck my wheels in the rear. The only time i ever lift it this high is to take the wheels off. i ride it about 2" off the ground everywhere except 90 degree turns for the most part.   So running the super pivot vertically sounds like what i am going to do. I am also going to shorten my lower bars a few inches and put the tabs on the front of the crossmember rather than the bottom to straighten the lower link to the upper (the bars were used in my previous link set up and i was going to try to reuse them without modifications) does this sound like it should work? Thanks so much for all the help!

It's hard to tell what will work for you from that pic. Just run with the imaginary lines and the intersection I already told you about. Maybe it will help you to take a pic level and from the side, throw it up on MS Paint and draw those lines.