rear coil spring specs - installed height/diameter

[lifespeed]

Does anybody here happen to know the installed height and diameter (at the spring perches) of the rear coil springs for 2003+ panthers? I recall the perch diameter both on the axle and the frame is smaller than the coil midsection. I would like to have some aftermarket springs made, but don't have this info. Don't have any rear coils to measure against either, but have air springs instead.

The air suspension works fine, but I need to significantly increase the spring rate as I am converting to torque arm rear suspension without the added "spring" of the four link binding, so what I have now won't work. Let's not do the air vs. coil argument, it doesn't apply here.

[MOTOWN]

Why not go with a set of coilover shocks?

[EMAS]

Does anybody here happen to know the installed height and diameter (at the spring perches) of the rear coil springs for 2003+ panthers? I recall the perch diameter both on the axle and the frame is smaller than the coil midsection. I would like to have some aftermarket springs made, but don't have this info. Don't have any rear coils to measure against either, but have air springs instead.

The air suspension works fine, but I need to significantly increase the spring rate as I am converting to torque arm rear suspension without the added "spring" of the four link binding, so what I have now won't work. Let's not do the air vs. coil argument, it doesn't apply here.

03 up Panthers don't have a triangulated four link, they are parallel, so they don't have "spring" due to binding. That is why the 03+ cars already have the watts linkage.

As far as your custom springs go, I'd contact https://www.eatondetroitspring.com Panther springs are one of their standard items, so they certainly have the various stock specs and will twist them up to your specs for spring rate and ride height if their standard offering doesn't meet your needs.

[RubberCtyRauder]

03 up Panthers don't have a triangulated four link, they are parallel, so they don't have "spring" due to binding. That is why the 03+ cars already have the watts linkage.

As far as your custom springs go, I'd contact https://www.eatondetroitspring.com Panther springs are one of their standard items, so they certainly have the various stock specs and will twist them up to your specs for spring rate and ride height if their standard offering doesn't meet your needs.

He's building a 9" rear so it is all custom. And eaton Detroit spring gets poor ratings on their custom springs from CV.net A better choice is Coil Spring Specialties or Custom Coil Spring. I don't recall the name

[lifespeed]

Why not go with a set of coilover shocks?

The outboard shocks have no clearance to grow to coilover size. Great geometry and 1:1 shock action at their factory location, though.

Besides, I need to be able to put an overload air bag inside the coil. Weight on the rear increases by 600 to 800 lbs on occasion.

[lifespeed]

03 up Panthers don't have a triangulated four link, they are parallel, so they don't have "spring" due to binding. That is why the 03+ cars already have the watts linkage.

This is a common misconception. Visualize the control arms moving through two different arcs at the axle attachment point from the side of the car. Then compress one side of the axle more than the other. Since the axle can't twist the bushings compress and lengthen. Which is why poly control arm bushings stiffen the suspension.

[lifespeed]

He's building a 9" rear so it is all custom. And eaton Detroit spring gets poor ratings on their custom springs from CV.net A better choice is Coil Spring Specialties or Custom Coil Spring. I don't recall the name

I'm going to do something like this (http://www.ground-control-store.com/products/description.php/II=644/CA=96) so I can dial in ride height.

[MOTOWN]

The outboard shocks have no clearance to grow to coilover size. Great geometry and 1:1 shock action at their factory location, though.

Besides, I need to be able to put an overload air bag inside the coil. Weight on the rear increases by 600 to 800 lbs on occasion.

I'm relocating my shocks inboard of the frame rails , and the moving the control arms inside the actual frame rails to accommodate a much wider tire , may go to a 9" rear axle at this point not sure yet.

[lifespeed]

I'm relocating my shocks inboard of the frame rails , and the moving the control arms inside the actual frame rails to accommodate a much wider tire , may go to a 9" rear axle at this point not sure yet.

That thought occurred to me too, but I decided the outboard shocks had to stay. 10" of tire is enough for me, I guess we have different priorities.

[lifespeed]

If anybody needs the info for future reference my installed height is about 9-1/4". Accuracy is probably not perfect, and the car is slightly lowered in the rear to your typical Marauder height with the fender lip 1/4" above the rear tire tread (stock diameter despite the wheel/tire upgrade).

I'll be running about 360 lbs/in with threaded adjusters linked above installed to the axle perch so the ride height can be made correct.

[lifespeed]

I spoke with the folks at Coil Spring Specialties. They were very cooperative and helpful in building something appropriate. The pigtail loop upper and lower is 2.4" I.D. should anybody need to specify a rear coil down the road. I will be using a flat ground lower finish to sit on a flat plate threaded adjuster, but the upper pigtail will remain.