mini tub with leaf springs

[72nova]

I have a 72 nova that i am in the process of mini tubbing. I am putting new frame rails in it and want to know about the leaf springs. Should I angle them like they were from the factory or put them in straight? From the factory, the front of the springs were 4" closer in the front than in the back. If you buy the kit from DSE they only move the rear of the spring. Did the factory do this to prevent side to side motion? Why don't the DSE kit have the springs this way. I'm confused, any opinions or answers would be greatly appreciated.

[David Pozzi]

I talked with Kyle about this some time ago. He stated angled was best, but the kit he developed moves just the rear to make it a lot easier to achieve tire clearance.

If you can move the whole frame rail in, that's probably the best way to go. I haven't found the reason for angling the leaf's in any book. It does give you a front intersection point for determining suspension roll axis that way.
David

[72nova]

Thanks for the reply. I am in the process of putting frame rails in now, so I think I am going to put the springs back in at the same angle as factory.

[chicane67]

Mounting the leafs so that the front eyes are slightly inboard of the rear eyes will cause the leafs to have more lateral stiffness. This can make the chassis feel tighter and may help prevent the rear suspension from binding due to lateral deflection of the leaf. However, if the leafs are offset too much, the suspension becomes too stiff laterally and rear side bite is lost.

Whenever the body moves over the rear end during cornering, the splayed leafs can cause rear steer that will help the car to turn. Also, if the right front spring eye is mounted more inboard than the left eye (measured from the corresponding tires), the right rear tire will tend to be loaded less than the left rear tire during acceleration (thanks to the left hand turn club). As a result, the chassis will tend to be tighter off the corner. Corner exit handling tends to be loose under opposite conditions Generally, moving the front spring eye 1 1/2" laterally will produce a noticeable effect to corner exit handling.

If you use a good bushing, to the likes of Global West or DSE delrin lined, you should be in good shape. If you are going to do some real hard driving, the addition of a panhard or watts link would cure you of any lateral effects from taking the angle out of the spring.

[68Formula]

So is a panhard or watts link unnecessary with the stock setup?

[chicane67]

Well, its not necessary with either... but when you remove some of the inhearent lateral stability from moving the springs, you need to get it back some how.