6 and 7 leaf springs...handling?

[Dreamcar]

If I'm not mistaken, the point of having the extra leaf on one side was to help with acceleration, and even the new Mopar XHD springs still come with the extra leaf on one side.

But my question is, how would having this extra leaf affect handling/cornering? Is this not the same as having a stiffer spring on one side? Do you slightly crank up the opposite side torsion bar to make up the difference and make the car handle evenly?

When I emailed Firmfeel about their HD springs, they said they match theirs from side to side for better handling. PST appears to have the same 6 on one side, 7 on the other design.

[HPP]

The extra leaf provides a higher control ratio on the spring set, so it does not have a huge impact on the spring rate. Some, yes, but not a lot. The difference will typically not be enough for most drivers to notice.  However you can get matched sets if that is your preference. I've used the bias design XHD sets without any handling adversity so it isn't like you will introduce a hazardous condition by using them.

[green69rt]

Just looked at mine to remember the setup.  The 7 leaf spring is on the passenger side, and it is actually just a 5 leaf spring with two half leaves in the front.  I seem to remember that the two half leafs are to compensate for body twist and axle windup from the high torque engines during hard acceleration.   My old RT handled good for it's age and I don't think you would notice a difference between mine and a full leaf setup.

After looking around at some vendors, some have 7 full leaves on the passenger side so who knows?? 

[Mike DC]

 
Yeah, it's not technically 7 leafs on the right, its a pair of half-leafs.  And more importantly they are on the front side of the axle.  That means they come into play more when the axle is "winding up" because the pinion is trying to climb up the ring gear (same thing that traction bars are designed to fight).  The extra right side leafs have less of an impact when the car isn't trying to accelerate. 

It's a smart setup for what it is.  I don't think you would notice any real left/right handling difference in normal street situations.

[Dreamcar]

 
Yeah, it's not technically 7 leafs on the right, its a pair of half-leafs.  And more importantly they are on the front side of the axle.  That means they come into play more when the axle is "winding up" because the pinion is trying to climb up the ring gear (same thing that traction bars are designed to fight).  The extra right side leafs have less of an impact when the car isn't trying to accelerate. 

It's a smart setup for what it is.  I don't think you would notice any real left/right handling difference in normal street situations.

I'm wondering if the Mopar XHD (new ones) have 7 full leafs?

[375instroke]

Looking forward, the axle wants to rotate counter clockwise under acceleration, lifting the right tire off the ground, and the pinion wants to rotate upwards.  The stiffer front right segment of the leaf spring uses the rotation of the axle along it's axis to counteract the rotation along the pinion's axis, lifting the right rear of the car instead of squatting, and losing traction.  It's just the front, so I'm sure it balances out, and when you think about it, aren't you accelerating out of turns anyways?  Traction under acceleration is important, too, so unless you want maximum grip on a skid pad with no acceleration, deceleration, or change in direction, or have a puny motor, use the staggered springs.   

[Dreamcar]

Looking forward, the axle wants to rotate counter clockwise under acceleration, lifting the right tire off the ground, and the pinion wants to rotate upwards.  The stiffer front right segment of the leaf spring uses the rotation of the axle along it's axis to counteract the rotation along the pinion's axis, lifting the right rear of the car instead of squatting, and losing traction.  It's just the front, so I'm sure it balances out, and when you think about it, aren't you accelerating out of turns anyways?  Traction under acceleration is important, too, so unless you want maximum grip on a skid pad with no acceleration, deceleration, or change in direction, or have a puny motor, use the staggered springs.   

Good points. Thanks for that.