rear suspension question

[dodge440]

Hey guys, just a quick one, does the leaf springs in a 70 Challenger run parallel, or is the distance between greater at the rear than the front?,ie, are they splayed?

[DartGT66]

The rear section is considerably longer than the front.

[peg leg]

About longitudinal placement, not spring shape.
I can only suggest that you measure, but are you asking whether they should or should not be parallel? I've never measured the Demon. Now I will!

[dodge440]

Hello peg leg, I have measured, and mine are splayed a reasonable amount.
I had the car tubbed to the chassis rails, and the springs have been shifted inside the rails. The company that did this fabricated rear spring mount positions, but they are somewhat further apart than the front spring hangers.

[Tarrbabe]

Comes from the factory with the rear of the springs splayed out 1.67 degrees. That is from my Chassis Book.

[rumblefish360]

Originally Posted by Tarrbabe

Comes from the factory with the rear of the springs splayed out 1.67 degrees. That is from my Chassis Book.

ATTA-BOUI!!!!!!!! Go to the source.

[dodge440]

In simpler terms, if I measured across from spring to spring, front and rear, what would the difference be?

[Tarrbabe]

Length of your spring. You would need to use a degree tool and a straight edge back to the rear, eye center to eye center. I'm sure there is a math formula that can figure it but I've never tried so never took the time to check. I have a Dart and the rear springs were straight on them.
There are several here that answer math questions all the time. Maybe they will chime in. I think it would be simple to obtain a degree tool and straight edge and figure it.

[John Kunkel]

The E body spring is 57", that radius makes a circumference of 358" so each degree would be a little less than an inch. Of course, this doesn't account for the arch in the spring which changes with the ride height.

[dodge440]

Ok, gotcha. circumference= pi D, divide by 360, = 1 (.99)", so each rear mount should be across 1/2" for a total of 1". It looks like I will have to get the spring seats on the diff relocated to bring the rear of the springs closer, I have 3".
Thanks for your help.

[John Kunkel]

If you multiply that .99" by Tarrbabe's 1.67 degrees the total spread should be more like 1 5/8". (again, not accounting for the arch in the spring)