I'm building a 4 bar rear end locator setup for my traditional Kustom. I'm Wonderin if the upper and lower bars have to be the same length on each side or can they be different lengths as long as they are level? Will this also effect rearend wrap during acceleration? Any guidance on this would be greatly appreciated.
You threw me a bit when you said "on each side". The left and right side absolutely have to be the same. If they weren't, there'd be major bind due to different arcs, and something would eventually break. The upper and lower bars can be and often are different lengths and situated at different angles. Generally speaking, it doesn't effect axle "wrap" such as an axle will do with leaf springs, because there's no flex...the bars hold the axle tight. However, the different lengths and/or angles do affect how the torque tends to cause the rear of the car to either squat or lift during acceleration, which in-turn affects traction. I'm not exactly sure how it works...we'll have to leave the details for those in the know. But those are the basics.
If the bars are parallel, but are different lengths, they won't have the same arc, and the axle will turn a bit (looking from the side of the vehicle) as the suspension compresses and rebounds. The bars can be the same length, but one situated further back than the other, and they'll still have the same arc...as long as the mounting point at the axle for both bars is the same distance from the centerline of the axle. Lots of variables.
the pinion will rotate if you make them diff. lengths. Pick up a stockcar ch***is book ,it will go into more depth with pictures.
Generally speaking, (there are exceptions...mostly in drag-racing) your pinion angle needs to be parallel with the output shaft of the transmission...probably 3 degrees.
Do some research. Look around on the net...read a book or two, to get a handle on automotive geometry. And don't forget to do searches here. Almost anything you can think of has been discussed.
Which is to say, your pinion angle changes as the ch***is rises and falls. Keep the bars the same length.
You could make the top vs the bottom different lengths no problem. Example: If top arm are shorter, that would cause the rear-end to twist downward/forward. If you had to do it, The longer, the better, Less response/affect. Driver Side vs P***enger Side, Not really. The shorter side would pull in more. However, that pull could work to your advantage if you factor that in with other "Uneven Factors" like Engine rotation and/or non-posi traction. Just add it to its driving characteristics. If you had to do it, The longer, the better, Less response/affect.
Got it. I'm gonna go with bars of equal length top and bottom. I plan on welding the bars together without any adjustment. Maybe a bit risky for an unproven ch***is but I can always make new bars if necessary. I've been going by Tex Smiths book,How to build hot rod ch***is. Great book, really nice job of covering all the bases. Just not alot on rear suspension. Any recommendations on rear suspension books?
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